ORIGINAL ARTICLE
High Self-efficacy Predicts Adherence to Surveillance Colonoscopy in Inflammatory Bowel Disease Sonia Friedman, MD,* Adam S. Cheifetz, MD,† Francis A. Farraye, MD, MSc,‡ Peter A. Banks, MD,* Frederick L. Makrauer, MD,* Robert Burakoff, MPH, MD,* Barbara Farmer, BA,* Leanne N. Torgersen, MPH, MS,* and Kelly E. Wahl, MFA§
Background: Patients with extensive ulcerative colitis or Crohn’s disease of the colon have an increased risk of colon cancer and require colonoscopic surveillance. In this study, we assessed individual self-efficacy (SE) to estimate the probability of adherence to surveillance colonoscopies.
Methods: Three hundred seventy-eight patients with ulcerative colitis or Crohn’s disease of the colon for at least 7 years and with at least one third of the colon involved participated in this cross-sectional questionnaire study performed at 3 tertiary referral inflammatory bowel disease clinics. Medical charts were abstracted for demographic and clinical variables. The questionnaire contained a group of items assessing SE for undergoing colonoscopy.
Results: We validated our 20-question SE scale and used 8 of the items that highlighted scheduling, preparation, and postprocedure recovery, to develop 2 shorter SE scales. All 3 scales were reliable with Cronbach’s a ranging from 0.845 to 0.905 and correlated with chart-documented adherence to surveillance colonoscopy (P , 0.001). We then developed logistic regression models to predict adherence to surveillance colonoscopy using each scale separately along with other key variables (i.e., disease location, knowledge of correct adherence intervals, and information sources of patients consulted regarding Crohn’s disease and ulcerative colitis) and demonstrated model accuracy up to 74%.
Conclusions: SE, as measured by our validated scales, correlates with chart-adherence to surveillance colonoscopy. Our adherence model, which includes SE, predicts adherence with 74% certainty. An 8-item validated clinical questionnaire can be administered to assess whether patients in this population may require further intervention for adherence. (Inflamm Bowel Dis 2014;20:1602–1610) Key Words: colonoscopy, adherence, self-efficacy, ulcerative colitis, Crohn’s disease
I
t is well established that patients with chronic and extensive ulcerative colitis (UC) or Crohn’s disease of the colon have an increased risk of developing colorectal cancer. From one large meta-analysis, the risk of cancer in patients with UC is estimated at 2% after 10 years, 8% after 20 years, and 18% after 30 years of disease.1 Data from a 30-year surveillance program in the United Kingdom calculated the risk of colorectal cancer to be 7.7% at 20 years and 15.8% at 30 years of disease.2 Studies of patients with extensive Crohn’s colitis have quoted a similarly increased risk.3,4 Because of this increased risk of colon cancer, individuals with chronic extensive UC and Crohn’s colitis need periodic colonoscopic surveillance. The Crohn’s and Colitis Foundation of Received for publication April 24, 2014; Accepted May 27, 2014. From the *Department of Medicine, Division of Gastroenterology, Brigham and Women’s Hospital; †Department of Medicine, Division of Gastroenterology, Beth Israel Deaconess Medical Center; ‡Department of Medicine, Section of Gastroenterology, Boston Medical Center, Boston, Massachusetts; and §Department of Analysis and Information Management, University of California, Los Angeles, California. Supported by an unrestricted grant from Procter and Gamble. The authors have no conflicts of interest to disclose. Reprints: Sonia Friedman, MD, Center for Crohn’s and Colitis, 850 Boylston Street, Chestnut Hill, Boston, MA 02467 (e-mail: [email protected]). Copyright © 2014 Crohn’s & Colitis Foundation of America, Inc. DOI 10.1097/MIB.0000000000000125 Published online 16 July 2014.
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America recommends to have a colonoscopy every 2 years after 8 to 10 years of disease.5 The American Gastroenterological Association recommends that with a negative surveillance colonoscopy, subsequent surveillance examinations should be performed in 1 to 3 years until UC has been present for 20 years with subsequent examinations every 1 to 2 years.6,7 In our previous study, we have shown that only about three-fourths of our patients with chronic extensive colitis had surveillance colonoscopies at less than 3-year intervals.8 The mean interval between surveillance colonoscopies was 2.71 years. There were multiple statistically significant categories of reasons patients gave for nonadherence including logistics, health perceptions, procedure problems, and stress regarding the procedure, job, or personal life. The most frequently cited most important reason for nonadherence was difficulty with the bowel preparation. Given the importance of surveillance colonoscopies and the significant difficulties associated with adherence, we wanted to predict which patients were most likely not to adhere to recommendations and might benefit from educational or behavioral intervention. In this study, we assessed self-efficacy (SE) to help calculate the probability of adherence. Social cognitive theory has established the association of SE with a person’s ability to perform specific tasks. Perceived SE, as a psychological construct, measures a person’s beliefs in his/her ability to undertake Inflamm Bowel Dis Volume 20, Number 9, September 2014
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High SE Predicts Colonoscopy Adherence in IBD
(i.e., organize and execute) the behaviors necessary to finish a given task, such as completing the process of having a successful colonoscopy.9 SE beliefs have a significant effect on how a person will persist in performing a task over time, how much effort a person will expend despite obstacles, and how engaged the person’s coping behaviors will be when he or she masters a skill or a regimen. As a judgment of capability, perceived SE is task specific. In the context of surveillance colonoscopies in patients with inflammatory bowel disease (IBD), those who are most certain that they “can do” all of the steps it takes to undergo a colonoscopy should be the most successful at completing them. To measure the SE of our patients to undergo a surveillance colonoscopy, we developed and validated a specialized SE scale. We then correlated this scale and other factors measured in a larger questionnaire study to develop a model that predicts which patients are most likely to adhere to colonoscopic surveillance recommendations.
MATERIALS AND METHODS All patients with UC or Crohn’s colitis for at least 7 years with at least one third of the colon affected were asked to participate in a large cross-sectional study. The study’s questionnaire included items exploring adherence to surveillance colonoscopies, patients’ risk perception and worry, quality of life, attitudes toward colonoscopies and IBD, and sources of information about IBD. Results from parts of this questionnaire have been reported previously.8,10 The 20-page questionnaire was self-administered by each patient and took approximately 40 minutes to complete. Part of this questionnaire included an SE scale regarding the ability to undergo a colonoscopy successfully (Fig. 1). Patients were paid $20.00 to respond to the survey. The study was conducted from October 2007 to May 2009. The Inflammatory Bowel Disease Centers of 3 major Boston hospitals participated in this study: Brigham and Women’s Hospital, Beth Israel Deaconess Medical Center, and Boston Medical Center. The institutional review board at each institution approved the study. Consent was obtained from each patient before administering the questionnaire and performing chart review.
Validation
FIGURE 1. Original colonoscopy SE scale with 20 items (n ¼ 353).
study and completed the questionnaire (72%). Of 222 eligible patients from the Beth Israel Deaconess Medical Center group, 180 patients consented and completed the questionnaire (81%). Of 53 eligible patients from the Boston Medical Center group, 38 patients consented and completed the questionnaire (72%).
Chart Review A chart review was performed for each patient, and all colonoscopies and histopathology were recorded. Charts were abstracted for demographic data, medication use, colonoscopy and pathology results, any surgical intervention, and disease type, location, and severity.
Surveillance Protocol
The questionnaire was first validated using focus groups of health care workers (physicians, physician assistants, nurses, and administrative staff) and then piloted in 3 different focus groups of 20 patients with IBD. After each focus group, the questionnaire was revised to make it more understandable to patients and more reflective of common patient concerns regarding colonoscopy and IBD.
Our protocol for surveillance colonoscopies was to perform 4-quadrant biopsies every 10 cm and biopsies from masses, strictures, and other suspicious lesions or to obtain 6 biopsies from each segment of the colon with more frequent sampling of the sigmoid and rectum.
Patients
In this study and in our previous study, we used chartdocumented rather than self-documented adherence. To measure chart-documented adherence, we calculated mean time between surveillance colonoscopies by chart review. For this study and our previous study,8 our inclusion criteria were more restrictive so that we could accurately assess chart-adherence to correlate it with SE
Of the medical records queried at all 3 hospitals, in our original study population, there were 514 patients with either Crohn’s or UC who met the inclusion criteria and consented to participate in the study. Of 411 eligible patients from the Brigham and Women’s Hospital group, 296 patients consented for the
Measurement of Chart-documented Adherence
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and other variables measured in our questionnaire. To calculate the chart-reported surveillance intervals, we included only the colonoscopies performed at the 3 study hospitals and only the colonoscopies performed after 7 years of disease. Before we calculated the surveillance intervals, we ensured that all patients in this study had their colonoscopies performed at the study hospitals and none at outside hospitals, so that we had accurate records of all colonoscopies. If a patient participated in this study before 3 years had elapsed since the 7-year anniversary mark of their IBD diagnosis, but they had not yet had a colonoscopy after the 7-year mark, they were not included in this study. If a patient participated in this study after 3 years had elapsed since the 7-year anniversary, but had not yet had a colonoscopy, they were counted as nonadherent. For patients who had a colonoscopy ,3 years after the 7-year anniversary and then another procedure after the initial one, only the second interval was counted in our adherence calculations. Finally, if there were .3 years since the last procedure for a qualifying case, we used that last interval in the analysis. For all of the analyses in this article, we used a 3-year chart-reported surveillance interval. In all, 378 patients met the entry criteria for this study.
SE Questionnaire All of the 378 patients in our restricted study population filled out a group of SE assessment items included as part of our larger questionnaire. We called this SE scale as the Colonoscopy SE Scale (Fig. 1).11 The scale for each SE question ranged from
0 (“Cannot Do At All”) to 10 (“Highly Certain Can Do”). We included in this initial SE analysis only those patients of the 378 who responded to all 20 questions of the scale (n ¼ 353). The scale is reliable with a Cronbach’s a of 0.905. The content validity of the scale was verified by close examination of the items that constitute the scale. We confirmed that they accurately reflect important elements of colonoscopy experience of patients with IBD by testing the relevant items in this survey bank (along with the entire questionnaire) on focus groups of health care workers and pilot groups of patients. Of 6 physicians on a panel reviewing this scale’s content, 100% concurred that none of the scale’s 20 items should be excluded from the questionnaire. No additional items not already included on the survey instrument were endorsed by 100% of the panel. Of all 20 items on the Colonoscopy SE Scale, the mean response was 8.835 with a range of means of 7.380 to 9.567 depending on the item; an additive scale score constructed from these items has a mean of 176.7 out of 200 (SD ¼ 24.12) (Table 1). Because of this high mean compared with the scale score’s midpoint of 100, with limited variance among responses, we readministered a shorter 11-question version of the Colonoscopy SE Scale with heightened language defining the endpoints, i.e., “Cannot Do EVERY TIME I have a colonoscopy” to “Highly Certain Can Do EVERY TIME I have a colonoscopy.” We called this 11-question version the New SE Scale (Fig. 2). The New SE Scale had a lower mean response for all items (7.678) and range of means for items (5.319–8.582), and proved reliable with
TABLE 1. Summary Statistics of All 4 Self-Efficacy Scales
Colonoscopy SE Scale: summary item statistics Item means Item variances Interitem covariances Interitem correlations New SE scale: summary item statistics Item means Item variances Interitem covariances Interitem correlations Top Five SE scale: summary item statistics Item means Item variances Interitem covariances Interitem correlations Highly Certain SE Scale: summary item statistics Item means Item variances Interitem covariances Interitem correlations
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Mean
Minimum
Maximum
Range
Maximum/Minimum
Variance
No. Items
8.835 4.088 1.316 0.345
7.380 1.468 0.417 0.112
9.567 8.833 4.218 0.735
2.187 7.365 3.801 0.623
1.296 6.017 10.115 6.566
0.387 3.828 0.301 0.011
20 20 20 20
7.678 7.042 2.135 0.311
5.319 4.456 0.885 0.113
8.582 11.649 6.478 0.649
3.262 7.192 5.592 0.536
1.613 2.614 7.316 5.733
0.956 4.553 0.927 0.014
11 11 11 11
3.969 2.181 0.884 0.415
3.292 1.492 0.533 0.262
4.429 3.039 1.878 0.633
1.137 1.546 1.344 0.371
1.345 2.036 3.520 2.419
0.235 0.417 0.090 0.013
8 8 8 8
0.638 0.212 0.087 0.412
0.434 0.168 0.052 0.254
0.787 0.251 0.152 0.616
0.352 0.083 0.100 0.362
1.811 1.491 2.938 2.422
0.022 0.001 0.000 0.009
8 8 8 8
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FIGURE 3. Top box and highly certain SE scales, each with the same 8 items selected from the colonoscopy SE scale (n ¼ 366).
FIGURE 2. New SE scale with 11 items (n ¼ 282).
a Cronbach’s a of 0.827; however, we were able to collect responses to the New SE Scale for only a subset of our study population: 282 of 378 patients. Our priority was to include the greatest number of patient responses possible in our development of these SE scales, which led us to choose 8 items from the original Colonoscopy SE Scale (n ¼ 353), items that highlighted scheduling, the colonoscopy preparation process, and recovery after the procedure. We recoded the items’ responses as follows: 0 to 6 recoded to 1, 7 recoded to 2, 8 recoded to 3, 9 recoded to 4, and 10 recoded to 5 (the scale’s midpoint becoming 3, which was formerly 8). We renamed this 8-item recode of the Colonoscopy SE Scale the Top Five SE Scale (Fig. 3), given its source was the top 5 points of the original scale items, with the bottom of the scale collapsed into the lowest point of the new scale. The Top Five SE Scale correlated highly with the New SE Scale, and it was reliable with a Cronbach’s a of 0.845 (n ¼ 366). The mean of all items was 3.969, with 3.292 to 4.429 as the range of means; the additive scale score had a mean of 31.75 (SD ¼ 8.18). The Top Five SE Scale correlated highly with the Colonoscopy SE Scale. To create a scale that could be administered more simply on an ad hoc basis in clinic, we chose from our original survey instrument the same 8 questions as the Top Five SE Scale and
recoded the responses of 0 to 9 as 0 and the responses of 10 as 1. We named this scale as the Highly Certain SE Scale, given how patients received 1 point for choosing the top of the scale (“Highly Certain Can Do”) for each item. For the Highly Certain SE Scale, 133 patients (36.3%) had additive scores from 0 to 4, and 233 patients (63.7%) had scores from 5 to 8. This cut point, between 4 and 5, represented the greatest change in adherence rate between recipients of any 2 consecutive Highly Certain SE Scale scores: patients with scores of 4 adhered at 61.1%, whereas those with a score of 5 adhered at 87.2% (Fig. 4). Patients who scored 5 or above on the Highly Certain SE Scale (i.e., patients who marked 10 on at least 5 of the 8 items) were more likely to adhere
FIGURE 4. Highly certain SE scale scores compared with the percentage of patients who adhere to surveillance colonoscopies. Scores of 5 and above belong to patients more likely to adhere. www.ibdjournal.org |
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than lower scoring patients (P , 0.001). This Highly Certain SE Scale (Fig. 3) was reliable with a Cronbach’s a of 0.848 (n ¼ 366) and correlated highly with the original Colonoscopy SE Scale and the Top Five SE Scale. Creating and validating these shorter, 8-item scales yielded item means closer to the scale midpoints, promoted variance, and included the largest number of patient responses, which provided us an array of SE measures from which to choose in building our adherence models. We confirmed the construct validity for each of the 3 scales (Colonoscopy SE Scale, Top Five SE Scale, and Highly Certain SE Scale) individually by using a multigroup factor analysis approach.12,13 Multiple groups of variables were selected from the data collected for this study including multiple traits assessed (i.e., patients’ self-reported quality of life, patients’ perception of cancer risk if they did not have routine colonoscopies, whether patients could accurately report how frequently they need colonoscopies and patients’ UC or CD clinical score), and 2 methods (survey data collection and chart extraction). A principal component analysis without rotation confirmed the separate groups of variables that would be used for the multiple-group factor analysis and which variables belonged in each variable group. Two factors formed consistently, with psychological characteristics (SE levels, knowledge, and beliefs) loading together and disease characteristics (clinical score and quality of life) loading together. A second set of principal components analyses calculated each variable group’s separate single-factor score using the regression method. Both convergent and divergent validity were demonstrated by
a correlation matrix of the factor scores (Table 2). Measures that correlated with all 3 scale scores, such as quality of life, supported convergent validity, whereas measures assessing distinct phenomena, such as clinical score, perception of cancer risk, and patients’ accurate report of how often they need colonoscopies, did not correlate with any of the 3 scales and thus supported divergent validity. We then confirmed the scales’ concurrent validity (criterion-related validity) through correlations of all 3 scales with categories of reasons why patients did not adhere to surveillance colonoscopies and also through multiple correlations with survey and chart-collected items, which are reported in detail in the Results section. All statistical analyses were performed using SPSS for Macintosh software (version 21, Chicago, IL). Descriptive statistics were calculated to report the items’ central tendencies and distributions. When data did not distribute normally, nonparametric statistical analyses were performed.14 A Spearman’s correlation coefficient was calculated to ascertain any statistical relationship between 2 ordinal fields or 1 ordinal and 1 continuous field. A Mann–Whitney U test was performed when dichotomous variables indicated group membership and nonnormally distributed fields were the test variables. Kruskal–Wallis H tests were performed on nonnormally distributed fields when the group variables were nominal and indicated 3 or more groups. Logistic regression models were built using adherence as the dichotomous categorical outcome variable, with both nominal
TABLE 2. Validation of Colonoscopy SE, Top Five SE, and Highly Certain SE Scales Correlation Coefficient with Colonoscopy SE Scale Multiple-group factor analysis factors Clinical scorea/SIBDQ factor scoreb Psychology/Colonoscopy SE scale factor scorec Psychology/Top Five SE Scale factor scorec Psychology/Highly Certain SE Scale factor scorec Individual items and scores Clinical scorea Patients’ perception of cancer risk (1) Patients’ accurate report of how often they need colonoscopies (2) SIBDQ (Quality of Life Scale)
Correlation Coefficient with Top Five SE Scale
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P Significance (2-tailed)
0.287 0.394
0.246 0.345
0.215 0.364
,0.001 ,0.001
0.363
0.370
0.379
,0.001
0.392
0.401
0.439
,0.001
20.062 0.091 0.064
20.063 0.062 0.045
20.050 0.079 0.057
0.284
0.244
0.217
Clinical Score/SIBDQ factor score does not correlate with any Psychology/SE Scale factor score (P . 0.15). a Clinical Score indicates disease remission (HBI #4; Mayo #2). b Clinical Score included in factor score with SIBDQ. c Each SE Scale included in factor score with additional psychological measures (1) and (2). HBI, Harvey–Bradshaw Index.
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NS NS NS ,0.001
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and continuous variables serving as the predictors. The models were developed through exploratory stepwise methods. All predictors met our criteria for inclusion in the models by demonstrating no statistically significant correlation (P , 0.05) with any other predictor variable. A listwise deletion strategy was used to account for missing values. The models were assessed for multicollinearity, and an examination of the models’ residuals was performed. No cases were excluded as outliers from the models.
RESULTS Three hundred seventy-eight patients were included in this study. One hundred eighty-nine patients (50%) had UC and 189 patients (50%) had CD. Two hundred eight patients (55%) were female and 170 (45%) were male. Altogether, 90.8% had extensive colitis. The mean age was 49.9 (range, 24–88), and the mean disease duration was 22.9 years (range, 8.19–51.40). The total number of surveillance colonoscopies performed was 1529. The mean number of colonoscopies performed per patient after 7 years of disease was 4.01 (range, 1–12). Only 24 colonoscopies (1.6%) were performed for increased symptoms. Altogether, 1465 colonoscopies (95.8%) were complete examinations to the cecum. The mean interval between surveillance colonoscopies was 2.71 years (range, 0.27–36.8). By chart review, 282 patients (74.5%) had chart-documented adherence or less than 3-year intervals, on average, between colonoscopies. More detailed demographic data have been reported in our 2 previous studies with the same population of patients.8,10 In all, 353 patients were included when creating the Colonoscopy SE scale, and 366 were included in the Top Five and Highly Certain SE Scales. Mean, range, and variance are included for all scale items in Table 1. All 3 SE scales (Colonoscopy SE Scale, Top Five SE Scale, and Highly Certain SE Scale) correlated with chart-documented adherence (P , 0.001). All 3 SE scales also correlated with increasing age (P , 0.01) and retirement status (P , 0.01). In our previous article, we examined categories of reasons why patients do not adhere to surveillance colonoscopies. These categories included logistics, procedure problems, health perceptions, stress, prep issues, money/insurance, and misinformation. All 3 SE scales correlated negatively with patients reporting that they missed colonoscopies because of misinformation, logistics, health perceptions, stress, procedure problems, and prep issues (P , 0.01). We included the validated Short Form Inflammatory Bowel Disease Questionnaire (SIBDQ) in our large patient questionnaire.15 The SIBDQ is a simple, 10-item questionnaire that can be easily scored and interpreted by clinicians. The SIBDQ measurement of health-related quality of life in patients with IBD provides results parallel to those obtained with the full 32-item IBDQ.16 In this study, all 3 SE scales correlated positively with quality of life (P , 0.01). Given that adherence to surveillance colonoscopy is such an important part of IBD treatment, we sought to develop a model that would predict which patients were more or less
High SE Predicts Colonoscopy Adherence in IBD
likely to adhere. SE correlated highly with adherence, thus serving as a foundation for our model. Our larger IBD questionnaire and chart review collected demographic information, colon cancer risk perception, clinical disease extent and activity, sources of information about IBD, patients’ feelings about IBD and colon cancer, categories of reasons for nonadherence, quality of life, perception of doctor messages, and comorbidities. For identifying other variables for inclusion in our model, we used factor analysis to associate groups of related variables and to create single measures of relevant phenomena. Initial analysis to recognize potential predictors of adherence was performed using adherence and nonadherence group comparisons for continuous factor scores and variables and nonparametric tests for categorical variables. Correlations were assessed among all potential factors and variables for significance of confounding. Variables that correlated with adherence but did not correlate with each other were included in our logistic regression model. All 3 SE scales correlated positively with adherence and were used in 3 separate models with the following 2 variables entering each model: patients reporting a need for surveillance at incorrect intervals (negative correlation) and the extent to which patients reported using sources of information that are nonmedical people (e.g., friends, family, and other patients with IBD rather than physicians) (negative correlation). In an initial step, we forced a count of patients’ locations of disease to enter the model, because this predictor represented the initial physical state that may have precipitated any subsequent health-related knowledge or behavior (Table 3). Controlling for count of disease locations and taking all of the above variables into account in our model, we could predict adherence to surveillance colonoscopy with 74% certainty (Table 4). In our 3 separate adherence models, each of the 3 SE scales proved useful. To decrease the number of questions necessary to assess SE, we recommend using one of the two 8-question versions of the SE scales (Top Five or Highly Certain). In the context of seeing patients in the IBD clinic, we recommend scoring the questionnaire using the Highly Certain method. Those patients who score below 10 (“Highly Certain Can Do”) on 5 or more of the 8 items would be candidates for educational or psychological intervention.
DISCUSSION SE is understood to be an individual’s perception that he or she is likely to attain a specific goal; as a consequence, it must focus on a particular area of functioning. Although people might have high levels of SE regarding 1 realm of their personal performance, such as their ability to complete tasks at their jobs, they may harbor much lower SE when considering their attainment of health-related goals. The stronger the sense of a patient’s taskspecific SE, the greater the patient’s perseverance will be and the higher the likelihood that this given activity will be performed successfully. In light of the task-specific nature of any SE measurement, we must consider the targeted set of beliefs to be www.ibdjournal.org |
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TABLE 3. Frequencies of Outcome and Predictor Variables from Logistic Regression Models Colonoscopy SE Scale Top Five SE Scale and Highly Certain SE Scale (n ¼ 353 for scale; n ¼ 350 for model) (n ¼ 366 for scales; n ¼ 362 for models) On average, fewer than 3 years between colonoscopies No Yes Total Number of disease locationsa 2 3 4 5 6 7 8 Total Cases deleted from model Total scale creation cases Believed 3 or more years between scopes is recommended (or Did not know/Was not told) No Yes Total Scale: information sources are nonmedical peopleb Scale score 3 4 5 6 7 8 9 Total
Frequency 89 261 350 Frequency 29 58 82 64 79 30 8 350 3 353
Percent 25.4 74.6 100.0 Percent 8.3 16.6 23.4 18.3 22.6 8.6 2.3 100.0 Missing
Frequency 91 271 362 Frequency 29 60 84 67 80 33 9 362 4 366
Percent 25.1 74.9 100.0 Percent 8.0 16.6 23.2 18.5 22.1 9.1 2.5 100.0 Missing
Frequency 295 55 350
Percent 84.3 15.7 100
Frequency 303 59 362
Percent 83.7 16.3 100.0
Frequency 133 78 73 54 7 2 3 350
Percent 38.0 22.3 20.9 15.4 2.0 0.6 0.9 100.0
Frequency 140 78 75 55 9 2 3 362
Percent 38.7 21.5 20.7 15.2 2.5 0.6 0.8 100.0
Locations are ileum, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, and anus. At least one third or more of colon is involved in all patients. a Three types of nonmedical people were included: family, friends, and other patients with CD or UC. b Three-point scoring per item: “I have not used” ¼ 1; “I have used this source sometimes” ¼ 2; “I have used this source extensively” ¼ 3. Additive scale created, with Cronbach’s a of 0.598.
assessed for a relevant statistical construct. In our study, we used a specifically designed SE questionnaire to determine which patients had high SE for completing the colonoscopy process, and our instrument concentrated on a validated list of that process’s task components. We then found a positive correlation between our SE scores and the likelihood of adhering to a surveillance colonoscopy. We created a series of logistic regression models that included our SE scales (1 scale per model) to predict which patients with IBD were most likely to adhere to surveillance colonoscopies. Based on our models, patients demonstrating a high SE score on any of our 3 scales (Colonoscopy SE Scale,
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Top Five SE Scale, or Highly Certain SE Scale) were predicted to be more likely to adhere, and patients (1) having the wrong idea regarding when to come in for surveillance colonoscopies or (2) having reported themselves as more often receiving their diseaserelated information from nonmedical people were predicted to be less likely to adhere (P , 0.0001 for all 3 scales). A simple SE questionnaire administered in the gastroenterologist’s office, along with answers to a few additional questions, can help predict adherence at the 74% level. Useful SE assessments must be task-specific instead of overly broad or all encompassing in their scope; thus, generalized
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High SE Predicts Colonoscopy Adherence in IBD
TABLE 4. Logistic Regression Models of Adherence to Colonoscopy Surveillance Recommendations
Model 1: Included 20-item scale (n ¼ 350)a Constant No. disease locations Colonoscopy SE Scale Wrong idea regarding colonoscopy adherence interval Use of nonmedical people as information sources Model 2: Included 8-item scale, scale items recoded to top 5 points of scale (n ¼ 362)b Constant No. of disease locations Top Five SE Scale Wrong idea regarding colonoscopy adherence interval Use of nonmedical people as information sources Model 3: Included 8-item scale, only “highly certain” responses tallied (n ¼ 362)c Constant No. disease locations Highly Certain SE Scale Wrong idea regarding colonoscopy adherence interval Use of nonmedical people as information sources
95% CI for Odds Ratio Odds (Lower–Upper)
b
SE
Significance (P)
21.553 0.225 0.018 21.944 20.252
1.140 0.094 0.006 0.335 0.104
0.173 0.016 0.001 ,0.001 0.016
1.253 1.018 0.143 0.777
(1.043–1.505) (1.007–1.029) (0.074–0.276) (0.633–0.953)
20.254 0.207 0.060 21.899 20.237
0.778 0.092 0.016 0.326 0.103
0.744 0.024 ,0.001 ,0.001 0.021
1.230 1.062 0.150 0.789
(1.027–1.472) (1.030–1.095) (0.079–0.284) (0.644–0.965)
0.689 0.207 0.183 21.876 20.234
0.673 0.091 0.051 0.325 0.103
0.306 0.024 ,0.001 ,0.001 0.023
1.230 1.201 0.153 0.791
(1.028–1.472) (1.086–1.328) (0.081–0.289) (0.647–0.968)
R ¼ 0.174 (Cox & Snell), 0.257 (Nagelkerke). Model x2(4) ¼ 67.087; P , 0.0001. R ¼ 0.173 (Cox & Snell), 0.256 (Nagelkerke). Model x2(4) ¼ 68.745; P , 0.0001. c 2 R ¼ 0.169 (Cox & Snell), 0.250 (Nagelkerke). Model x2(4) ¼ 66.938; P , 0.0001. a 2
b 2
SE scales were not worthwhile for our predictive modeling effort. In this study, we have developed the first SE questionnaire that can be used uniquely in our population of patients with IBD for the specific issue of undergoing colonoscopies. Unlike the general population without IBD, our patients must undergo regular colonoscopies at short intervals for the rest of their lives. Because our patients are often diagnosed at a young age, this could mean 20 to 30 colonoscopies in a lifetime. Patients with high SE scores on our scales are more likely to demonstrate mastery of the colonoscopy experience and are thus more likely to complete it successfully and return on time for future colonoscopies. Our questionnaire could certainly be modified and tested in the general population to see which patients may need educational counseling before scheduling a colonoscopy for the appropriate surveillance of non-IBD populations. Another correlate with SE in our study was health-related quality of life. The higher a person’s health-related quality of life, the higher his or her SE. This reasonably follows because patients with better health are more likely to tolerate the colonoscopy process. Patients who gave reasons for missing a colonoscopy that included the categories of misinformation, logistics, health perceptions, stress, procedure problems, and prep issues had lower SE scores, which is not surprising becasue offering such
reasons or excuses would indicate unsuccessful mastery and therefore low SE for the colonoscopy process. Perceived SE has been investigated thrice before to assess its role in the management of IBD in general. Keefer at al17 developed and validated an IBD-specific SE scale to evaluate how well patients were coping with stress and emotions, managing medical care, managing symptoms of disease, and maintaining remission. Zijlstra et al18 developed a questionnaire to look at SE in adolescents with IBD and Izaguirre et al19 looked qualitatively at SE in adolescents and young adults with IBD. In other non-IBD studies, perceived SE has been shown to affect physical, psychological, and social functioning in patients with cancer, multiple sclerosis, and diabetes.20–22 High SE has been linked to success in health screening for breast cancer,23 decreasing fear of childbirth and decreasing preference for cesarean section,24 smoking cessation,25 and prevention of eating disorders in adolescents.26 Because the first study to develop an SE scale specifically targeted towards patients with IBD who require surveillance colonoscopies, the strengths of our study are the high number of patients enrolled, the high response rates to the questionnaires, and the extensive analysis of all the interrelated questions and responses. To participate, the patients all visited university-based practices, which suggests a study weakness in that responses www.ibdjournal.org |
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found in private practice may not be similar. Additionally, the sample was predominantly white, was one-third Jewish (higher than average for patients with IBD), and had attained higher levels of education and higher levels of household income on average. Another factor that might affect adherence is that all patients in Massachusetts are mandated to have health insurance; thus the patients in this study might have had greater medical access than others in different states, consequently increasing their adherence. An additional factor that might have influenced SE is any colonoscopy preparation teaching undertaken by doctors and office staff. In general, patients received only the formal set of preparation instructions by e-mail or on paper and scheduled the appointment by e-mail or phone. There was no formal written, phone, or in-person colonoscopy education or teaching in any of the practices. In our previous study, we measured doctor message about colonoscopy by formally validating our Doctor Told Scale in this same population of patients.10 Although our Doctor Told Scale did correlate with chart-reported adherence (P , 0.01), it did not correlate with SE. Thus, although doctors may have spoken with patients about the colonoscopy procedure, we did not find that this communication was associated with improved SE. Patients who reported for more frequent colonoscopies had higher SE scores, and patients with a lower average time between screenings had a higher score on all 3 SE scales (P , 0.01). This aligns with social cognitive theory, which states that the more frequently a person successfully performs a task, the better his or her potential for SE enhancement. In summary, we demonstrate that high SE can predict adherence to surveillance colonoscopies in patients with IBD. We have validated a SE efficacy questionnaire specifically designed for patients with IBD undergoing surveillance colonoscopies, and we propose that it can be used in the IBD clinic to predict which patients will need educational intervention. In addition, we developed an adherence model, of which SE is a critical component, and this model can be used to predict adherence at the 74% level.
REFERENCES
1. Eadon JA, Abrams KR, Mayberry JF. The risk of colorectal cancer in ulcerative colitis: a meta-analysis. Gut. 2001;48:526–535. 2. Rutter MD, Saunders BP, Wilkinson KH, et al. Thirty-year analysis of a colonoscopic surveillance program for neoplasia in ulcerative colitis. Gastroenterology. 2006;130:1030–1038. 3. Friedman S, Rubin PH, Bodian C, et al. Screening and surveillance colonoscopy in chronic Crohn’s colitis: results of a surveillance program spanning 25 year. Clin Gastroenterol Hepatol. 2008;6:993–998. 4. Jess T, Loftus EV Jr, Velayos FS, et al. Risk of intestinal cancer in inflammatory bowel disease: a populations-based study from Olmstead County, Minnesota. Gastroenterology. 2006;130:1039–1046. 5. Itzkowitz SH, Present DH; Crohn’s and Colitis Foundation of America Colon Cancer in IBD Study Group. Consensus conference: colorectal cancer screening and surveillance in inflammatory bowel disease. Inflamm Bowel Dis. 2005;11:314–321.
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6. Farraye F, Odze RD, Eaden J, et al. AGA technical review on the diagnosis and management of colorectal neoplasia in inflammatory bowel disease. Gastroenterology. 2010;138:746–774. 7. Farraye FA, Odze RD, Eaden J, et al. AGA Institute Medical Position Panel on the diagnosis and management of colorectal neoplasia in inflammatory bowel disease. Gastroenterology. 2010;138:738–745. 8. Friedman S, Cheifetz A, Farraye FA, et al. Factors that affect adherence to surveillance colonoscopy in patients with inflammatory bowel disease. Inflamm Bowel Dis. 2013;19:534–539. 9. Bandura A. Health promotion by social cognitive means. Health Educ Behav. 2004;31:143–164. 10. Friedman S, Cheifetz A, Farraye FA, et al. Doctor message can alter patients’ behavior and attitudes regarding inflammatory bowel disease and colon cancer. Inflamm Bowel Dis. 2012;18:1531–1539. 11. DeVellis RF. Scale Development: Theory and Applications. 2nd ed. Thousand Oaks, CA: Sage Publications; 2003. 12. IBM SPSS Manual. Confirmatory factor analysis in SPSS [IBM SPSS Website]. 2011. Available at: http://www.304.ibd.com/support/docview. Accessed June 8, 2013. 13. IBM SPSS Manual. Multiple group factor analysis in SPSS [IBM SPSS Website]. 2011. Available at: http://www.304.ibd.com/support/docview. Accessed June 8, 2013. 14. Field A. Discovering Statistics Using IBM SPSS Statistics. 4th ed. Washington, DC: Sage Publications; 2013. 15. Irvine EJ, Zhou Q, Thompson AK. The Short Inflammatory Bowel Disease Questionnaire: a quality of life instrument for community physicians managing inflammatory bowel disease. CCRPT Investigators, Canadian Crohn’s Relapse Prevention Trial. Am J Gastroenterol. 1996;91:1571–1578. 16. Irvine EJ, Feagan B, Rochon J, et al. Quality of life: a valid and reliable measure of therapeutic efficacy in the treatment of inflammatory bowel disease: Canadian Crohn’s Relapse Prevention Trial Study Group. Gastroenterology. 1994;106:287–296. 17. Keefer L, Kiebles JL, Taft TH. The role of self-efficacy in inflammatory bowel disease management: preliminary validation of a disease-specific measure. Inflamm Bowel Dis. 2011;17:614–620. 18. Zijlstra M, De Bie C, Breif L, et al. Self-efficacy in adolescents with inflammatory bowel disease: a pilot study of “IBD-yourself”, a diseasespecific questionnaire. J Crohns Colitis. 2013;7:375–385. 19. Izaguirre MR, Keefer L. Development of a self-efficacy scale for adolescents and young adults with inflammatory bowel disease: a qualitative study. J Pediatr Gastroenterol Nutr. [published online ahead of print February 28, 2014]. doi: 10.1097/MPG.0000000000000357. 20. Phillips SM, McAuley E. Physical activity and quality of life in breast cancer survivors: the role of self-efficacy and health status. Psychooncology. 2014;23:27–34. 21. Nickel D, Spink K, Andersen M, et al. Attributions and self-efficacy for physical activity in multiple sclerosis. Psychol Health Med. 2014; 19:433–441. 22. Campbell T, Dunt D, Fitzgerald JL, et al. The impact of patient narratives on self-efficacy and self-care in Australians with type 2 diabetes: stage 1 results of a randomized trial. Health Promot Int. [published online ahead of print August 28, 2014]. doi: 10.1093/heapro/dat058. 23. Molina Y, Martinez-Gutierrez J, Pusche K, et al. Plans to obtain a mammogram among Chilean women: the roles of recommendations and selfefficacy. Health Educ Res. 2013;28:784–792. 24. Salomonsso B, Gullberg MT, Alehagen S, et al. Self-efficacy beliefs and fear of childbirth in nulliparous women. J Psychosom Obstet Gynaecol. 2013;34:116–121. 25. Sterling KL, Ford KH, Park H, et al. Scales of smoking-related selfefficacy, beliefs, and intention: assessing measurement invariance among intermittent and daily high school smokers. Am J Health Promot. 2014; 28:310–315. 26. Glasofer DR, Haaga DA, Hannallah L, et al. Self-efficacy beliefs and eating behavior in adolescent girls at-risk for excess weight gain and binge eating disorder. Int J Eat Disord. 2013;46:663–668.
High Self-efficacy Predicts Adherence to Surveillance Colonoscopy in Inflammatory Bowel Disease Sonia Friedman, MD,* Adam S. Cheifetz, MD,† Francis A. Farraye, MD, MSc,‡ Peter A. Banks, MD,* Frederick L. Makrauer, MD,* Robert Burakoff, MPH, MD,* Barbara Farmer, BA,* Leanne N. Torgersen, MPH, MS,* and Kelly E. Wahl, MFA§
Background: Patients with extensive ulcerative colitis or Crohn’s disease of the colon have an increased risk of colon cancer and require colonoscopic surveillance. In this study, we assessed individual self-efficacy (SE) to estimate the probability of adherence to surveillance colonoscopies.
Methods: Three hundred seventy-eight patients with ulcerative colitis or Crohn’s disease of the colon for at least 7 years and with at least one third of the colon involved participated in this cross-sectional questionnaire study performed at 3 tertiary referral inflammatory bowel disease clinics. Medical charts were abstracted for demographic and clinical variables. The questionnaire contained a group of items assessing SE for undergoing colonoscopy.
Results: We validated our 20-question SE scale and used 8 of the items that highlighted scheduling, preparation, and postprocedure recovery, to develop 2 shorter SE scales. All 3 scales were reliable with Cronbach’s a ranging from 0.845 to 0.905 and correlated with chart-documented adherence to surveillance colonoscopy (P , 0.001). We then developed logistic regression models to predict adherence to surveillance colonoscopy using each scale separately along with other key variables (i.e., disease location, knowledge of correct adherence intervals, and information sources of patients consulted regarding Crohn’s disease and ulcerative colitis) and demonstrated model accuracy up to 74%.
Conclusions: SE, as measured by our validated scales, correlates with chart-adherence to surveillance colonoscopy. Our adherence model, which includes SE, predicts adherence with 74% certainty. An 8-item validated clinical questionnaire can be administered to assess whether patients in this population may require further intervention for adherence. (Inflamm Bowel Dis 2014;20:1602–1610) Key Words: colonoscopy, adherence, self-efficacy, ulcerative colitis, Crohn’s disease
I
t is well established that patients with chronic and extensive ulcerative colitis (UC) or Crohn’s disease of the colon have an increased risk of developing colorectal cancer. From one large meta-analysis, the risk of cancer in patients with UC is estimated at 2% after 10 years, 8% after 20 years, and 18% after 30 years of disease.1 Data from a 30-year surveillance program in the United Kingdom calculated the risk of colorectal cancer to be 7.7% at 20 years and 15.8% at 30 years of disease.2 Studies of patients with extensive Crohn’s colitis have quoted a similarly increased risk.3,4 Because of this increased risk of colon cancer, individuals with chronic extensive UC and Crohn’s colitis need periodic colonoscopic surveillance. The Crohn’s and Colitis Foundation of Received for publication April 24, 2014; Accepted May 27, 2014. From the *Department of Medicine, Division of Gastroenterology, Brigham and Women’s Hospital; †Department of Medicine, Division of Gastroenterology, Beth Israel Deaconess Medical Center; ‡Department of Medicine, Section of Gastroenterology, Boston Medical Center, Boston, Massachusetts; and §Department of Analysis and Information Management, University of California, Los Angeles, California. Supported by an unrestricted grant from Procter and Gamble. The authors have no conflicts of interest to disclose. Reprints: Sonia Friedman, MD, Center for Crohn’s and Colitis, 850 Boylston Street, Chestnut Hill, Boston, MA 02467 (e-mail: [email protected]). Copyright © 2014 Crohn’s & Colitis Foundation of America, Inc. DOI 10.1097/MIB.0000000000000125 Published online 16 July 2014.
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America recommends to have a colonoscopy every 2 years after 8 to 10 years of disease.5 The American Gastroenterological Association recommends that with a negative surveillance colonoscopy, subsequent surveillance examinations should be performed in 1 to 3 years until UC has been present for 20 years with subsequent examinations every 1 to 2 years.6,7 In our previous study, we have shown that only about three-fourths of our patients with chronic extensive colitis had surveillance colonoscopies at less than 3-year intervals.8 The mean interval between surveillance colonoscopies was 2.71 years. There were multiple statistically significant categories of reasons patients gave for nonadherence including logistics, health perceptions, procedure problems, and stress regarding the procedure, job, or personal life. The most frequently cited most important reason for nonadherence was difficulty with the bowel preparation. Given the importance of surveillance colonoscopies and the significant difficulties associated with adherence, we wanted to predict which patients were most likely not to adhere to recommendations and might benefit from educational or behavioral intervention. In this study, we assessed self-efficacy (SE) to help calculate the probability of adherence. Social cognitive theory has established the association of SE with a person’s ability to perform specific tasks. Perceived SE, as a psychological construct, measures a person’s beliefs in his/her ability to undertake Inflamm Bowel Dis Volume 20, Number 9, September 2014
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(i.e., organize and execute) the behaviors necessary to finish a given task, such as completing the process of having a successful colonoscopy.9 SE beliefs have a significant effect on how a person will persist in performing a task over time, how much effort a person will expend despite obstacles, and how engaged the person’s coping behaviors will be when he or she masters a skill or a regimen. As a judgment of capability, perceived SE is task specific. In the context of surveillance colonoscopies in patients with inflammatory bowel disease (IBD), those who are most certain that they “can do” all of the steps it takes to undergo a colonoscopy should be the most successful at completing them. To measure the SE of our patients to undergo a surveillance colonoscopy, we developed and validated a specialized SE scale. We then correlated this scale and other factors measured in a larger questionnaire study to develop a model that predicts which patients are most likely to adhere to colonoscopic surveillance recommendations.
MATERIALS AND METHODS All patients with UC or Crohn’s colitis for at least 7 years with at least one third of the colon affected were asked to participate in a large cross-sectional study. The study’s questionnaire included items exploring adherence to surveillance colonoscopies, patients’ risk perception and worry, quality of life, attitudes toward colonoscopies and IBD, and sources of information about IBD. Results from parts of this questionnaire have been reported previously.8,10 The 20-page questionnaire was self-administered by each patient and took approximately 40 minutes to complete. Part of this questionnaire included an SE scale regarding the ability to undergo a colonoscopy successfully (Fig. 1). Patients were paid $20.00 to respond to the survey. The study was conducted from October 2007 to May 2009. The Inflammatory Bowel Disease Centers of 3 major Boston hospitals participated in this study: Brigham and Women’s Hospital, Beth Israel Deaconess Medical Center, and Boston Medical Center. The institutional review board at each institution approved the study. Consent was obtained from each patient before administering the questionnaire and performing chart review.
Validation
FIGURE 1. Original colonoscopy SE scale with 20 items (n ¼ 353).
study and completed the questionnaire (72%). Of 222 eligible patients from the Beth Israel Deaconess Medical Center group, 180 patients consented and completed the questionnaire (81%). Of 53 eligible patients from the Boston Medical Center group, 38 patients consented and completed the questionnaire (72%).
Chart Review A chart review was performed for each patient, and all colonoscopies and histopathology were recorded. Charts were abstracted for demographic data, medication use, colonoscopy and pathology results, any surgical intervention, and disease type, location, and severity.
Surveillance Protocol
The questionnaire was first validated using focus groups of health care workers (physicians, physician assistants, nurses, and administrative staff) and then piloted in 3 different focus groups of 20 patients with IBD. After each focus group, the questionnaire was revised to make it more understandable to patients and more reflective of common patient concerns regarding colonoscopy and IBD.
Our protocol for surveillance colonoscopies was to perform 4-quadrant biopsies every 10 cm and biopsies from masses, strictures, and other suspicious lesions or to obtain 6 biopsies from each segment of the colon with more frequent sampling of the sigmoid and rectum.
Patients
In this study and in our previous study, we used chartdocumented rather than self-documented adherence. To measure chart-documented adherence, we calculated mean time between surveillance colonoscopies by chart review. For this study and our previous study,8 our inclusion criteria were more restrictive so that we could accurately assess chart-adherence to correlate it with SE
Of the medical records queried at all 3 hospitals, in our original study population, there were 514 patients with either Crohn’s or UC who met the inclusion criteria and consented to participate in the study. Of 411 eligible patients from the Brigham and Women’s Hospital group, 296 patients consented for the
Measurement of Chart-documented Adherence
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and other variables measured in our questionnaire. To calculate the chart-reported surveillance intervals, we included only the colonoscopies performed at the 3 study hospitals and only the colonoscopies performed after 7 years of disease. Before we calculated the surveillance intervals, we ensured that all patients in this study had their colonoscopies performed at the study hospitals and none at outside hospitals, so that we had accurate records of all colonoscopies. If a patient participated in this study before 3 years had elapsed since the 7-year anniversary mark of their IBD diagnosis, but they had not yet had a colonoscopy after the 7-year mark, they were not included in this study. If a patient participated in this study after 3 years had elapsed since the 7-year anniversary, but had not yet had a colonoscopy, they were counted as nonadherent. For patients who had a colonoscopy ,3 years after the 7-year anniversary and then another procedure after the initial one, only the second interval was counted in our adherence calculations. Finally, if there were .3 years since the last procedure for a qualifying case, we used that last interval in the analysis. For all of the analyses in this article, we used a 3-year chart-reported surveillance interval. In all, 378 patients met the entry criteria for this study.
SE Questionnaire All of the 378 patients in our restricted study population filled out a group of SE assessment items included as part of our larger questionnaire. We called this SE scale as the Colonoscopy SE Scale (Fig. 1).11 The scale for each SE question ranged from
0 (“Cannot Do At All”) to 10 (“Highly Certain Can Do”). We included in this initial SE analysis only those patients of the 378 who responded to all 20 questions of the scale (n ¼ 353). The scale is reliable with a Cronbach’s a of 0.905. The content validity of the scale was verified by close examination of the items that constitute the scale. We confirmed that they accurately reflect important elements of colonoscopy experience of patients with IBD by testing the relevant items in this survey bank (along with the entire questionnaire) on focus groups of health care workers and pilot groups of patients. Of 6 physicians on a panel reviewing this scale’s content, 100% concurred that none of the scale’s 20 items should be excluded from the questionnaire. No additional items not already included on the survey instrument were endorsed by 100% of the panel. Of all 20 items on the Colonoscopy SE Scale, the mean response was 8.835 with a range of means of 7.380 to 9.567 depending on the item; an additive scale score constructed from these items has a mean of 176.7 out of 200 (SD ¼ 24.12) (Table 1). Because of this high mean compared with the scale score’s midpoint of 100, with limited variance among responses, we readministered a shorter 11-question version of the Colonoscopy SE Scale with heightened language defining the endpoints, i.e., “Cannot Do EVERY TIME I have a colonoscopy” to “Highly Certain Can Do EVERY TIME I have a colonoscopy.” We called this 11-question version the New SE Scale (Fig. 2). The New SE Scale had a lower mean response for all items (7.678) and range of means for items (5.319–8.582), and proved reliable with
TABLE 1. Summary Statistics of All 4 Self-Efficacy Scales
Colonoscopy SE Scale: summary item statistics Item means Item variances Interitem covariances Interitem correlations New SE scale: summary item statistics Item means Item variances Interitem covariances Interitem correlations Top Five SE scale: summary item statistics Item means Item variances Interitem covariances Interitem correlations Highly Certain SE Scale: summary item statistics Item means Item variances Interitem covariances Interitem correlations
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Mean
Minimum
Maximum
Range
Maximum/Minimum
Variance
No. Items
8.835 4.088 1.316 0.345
7.380 1.468 0.417 0.112
9.567 8.833 4.218 0.735
2.187 7.365 3.801 0.623
1.296 6.017 10.115 6.566
0.387 3.828 0.301 0.011
20 20 20 20
7.678 7.042 2.135 0.311
5.319 4.456 0.885 0.113
8.582 11.649 6.478 0.649
3.262 7.192 5.592 0.536
1.613 2.614 7.316 5.733
0.956 4.553 0.927 0.014
11 11 11 11
3.969 2.181 0.884 0.415
3.292 1.492 0.533 0.262
4.429 3.039 1.878 0.633
1.137 1.546 1.344 0.371
1.345 2.036 3.520 2.419
0.235 0.417 0.090 0.013
8 8 8 8
0.638 0.212 0.087 0.412
0.434 0.168 0.052 0.254
0.787 0.251 0.152 0.616
0.352 0.083 0.100 0.362
1.811 1.491 2.938 2.422
0.022 0.001 0.000 0.009
8 8 8 8
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FIGURE 3. Top box and highly certain SE scales, each with the same 8 items selected from the colonoscopy SE scale (n ¼ 366).
FIGURE 2. New SE scale with 11 items (n ¼ 282).
a Cronbach’s a of 0.827; however, we were able to collect responses to the New SE Scale for only a subset of our study population: 282 of 378 patients. Our priority was to include the greatest number of patient responses possible in our development of these SE scales, which led us to choose 8 items from the original Colonoscopy SE Scale (n ¼ 353), items that highlighted scheduling, the colonoscopy preparation process, and recovery after the procedure. We recoded the items’ responses as follows: 0 to 6 recoded to 1, 7 recoded to 2, 8 recoded to 3, 9 recoded to 4, and 10 recoded to 5 (the scale’s midpoint becoming 3, which was formerly 8). We renamed this 8-item recode of the Colonoscopy SE Scale the Top Five SE Scale (Fig. 3), given its source was the top 5 points of the original scale items, with the bottom of the scale collapsed into the lowest point of the new scale. The Top Five SE Scale correlated highly with the New SE Scale, and it was reliable with a Cronbach’s a of 0.845 (n ¼ 366). The mean of all items was 3.969, with 3.292 to 4.429 as the range of means; the additive scale score had a mean of 31.75 (SD ¼ 8.18). The Top Five SE Scale correlated highly with the Colonoscopy SE Scale. To create a scale that could be administered more simply on an ad hoc basis in clinic, we chose from our original survey instrument the same 8 questions as the Top Five SE Scale and
recoded the responses of 0 to 9 as 0 and the responses of 10 as 1. We named this scale as the Highly Certain SE Scale, given how patients received 1 point for choosing the top of the scale (“Highly Certain Can Do”) for each item. For the Highly Certain SE Scale, 133 patients (36.3%) had additive scores from 0 to 4, and 233 patients (63.7%) had scores from 5 to 8. This cut point, between 4 and 5, represented the greatest change in adherence rate between recipients of any 2 consecutive Highly Certain SE Scale scores: patients with scores of 4 adhered at 61.1%, whereas those with a score of 5 adhered at 87.2% (Fig. 4). Patients who scored 5 or above on the Highly Certain SE Scale (i.e., patients who marked 10 on at least 5 of the 8 items) were more likely to adhere
FIGURE 4. Highly certain SE scale scores compared with the percentage of patients who adhere to surveillance colonoscopies. Scores of 5 and above belong to patients more likely to adhere. www.ibdjournal.org |
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than lower scoring patients (P , 0.001). This Highly Certain SE Scale (Fig. 3) was reliable with a Cronbach’s a of 0.848 (n ¼ 366) and correlated highly with the original Colonoscopy SE Scale and the Top Five SE Scale. Creating and validating these shorter, 8-item scales yielded item means closer to the scale midpoints, promoted variance, and included the largest number of patient responses, which provided us an array of SE measures from which to choose in building our adherence models. We confirmed the construct validity for each of the 3 scales (Colonoscopy SE Scale, Top Five SE Scale, and Highly Certain SE Scale) individually by using a multigroup factor analysis approach.12,13 Multiple groups of variables were selected from the data collected for this study including multiple traits assessed (i.e., patients’ self-reported quality of life, patients’ perception of cancer risk if they did not have routine colonoscopies, whether patients could accurately report how frequently they need colonoscopies and patients’ UC or CD clinical score), and 2 methods (survey data collection and chart extraction). A principal component analysis without rotation confirmed the separate groups of variables that would be used for the multiple-group factor analysis and which variables belonged in each variable group. Two factors formed consistently, with psychological characteristics (SE levels, knowledge, and beliefs) loading together and disease characteristics (clinical score and quality of life) loading together. A second set of principal components analyses calculated each variable group’s separate single-factor score using the regression method. Both convergent and divergent validity were demonstrated by
a correlation matrix of the factor scores (Table 2). Measures that correlated with all 3 scale scores, such as quality of life, supported convergent validity, whereas measures assessing distinct phenomena, such as clinical score, perception of cancer risk, and patients’ accurate report of how often they need colonoscopies, did not correlate with any of the 3 scales and thus supported divergent validity. We then confirmed the scales’ concurrent validity (criterion-related validity) through correlations of all 3 scales with categories of reasons why patients did not adhere to surveillance colonoscopies and also through multiple correlations with survey and chart-collected items, which are reported in detail in the Results section. All statistical analyses were performed using SPSS for Macintosh software (version 21, Chicago, IL). Descriptive statistics were calculated to report the items’ central tendencies and distributions. When data did not distribute normally, nonparametric statistical analyses were performed.14 A Spearman’s correlation coefficient was calculated to ascertain any statistical relationship between 2 ordinal fields or 1 ordinal and 1 continuous field. A Mann–Whitney U test was performed when dichotomous variables indicated group membership and nonnormally distributed fields were the test variables. Kruskal–Wallis H tests were performed on nonnormally distributed fields when the group variables were nominal and indicated 3 or more groups. Logistic regression models were built using adherence as the dichotomous categorical outcome variable, with both nominal
TABLE 2. Validation of Colonoscopy SE, Top Five SE, and Highly Certain SE Scales Correlation Coefficient with Colonoscopy SE Scale Multiple-group factor analysis factors Clinical scorea/SIBDQ factor scoreb Psychology/Colonoscopy SE scale factor scorec Psychology/Top Five SE Scale factor scorec Psychology/Highly Certain SE Scale factor scorec Individual items and scores Clinical scorea Patients’ perception of cancer risk (1) Patients’ accurate report of how often they need colonoscopies (2) SIBDQ (Quality of Life Scale)
Correlation Coefficient with Top Five SE Scale
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P Significance (2-tailed)
0.287 0.394
0.246 0.345
0.215 0.364
,0.001 ,0.001
0.363
0.370
0.379
,0.001
0.392
0.401
0.439
,0.001
20.062 0.091 0.064
20.063 0.062 0.045
20.050 0.079 0.057
0.284
0.244
0.217
Clinical Score/SIBDQ factor score does not correlate with any Psychology/SE Scale factor score (P . 0.15). a Clinical Score indicates disease remission (HBI #4; Mayo #2). b Clinical Score included in factor score with SIBDQ. c Each SE Scale included in factor score with additional psychological measures (1) and (2). HBI, Harvey–Bradshaw Index.
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NS NS NS ,0.001
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and continuous variables serving as the predictors. The models were developed through exploratory stepwise methods. All predictors met our criteria for inclusion in the models by demonstrating no statistically significant correlation (P , 0.05) with any other predictor variable. A listwise deletion strategy was used to account for missing values. The models were assessed for multicollinearity, and an examination of the models’ residuals was performed. No cases were excluded as outliers from the models.
RESULTS Three hundred seventy-eight patients were included in this study. One hundred eighty-nine patients (50%) had UC and 189 patients (50%) had CD. Two hundred eight patients (55%) were female and 170 (45%) were male. Altogether, 90.8% had extensive colitis. The mean age was 49.9 (range, 24–88), and the mean disease duration was 22.9 years (range, 8.19–51.40). The total number of surveillance colonoscopies performed was 1529. The mean number of colonoscopies performed per patient after 7 years of disease was 4.01 (range, 1–12). Only 24 colonoscopies (1.6%) were performed for increased symptoms. Altogether, 1465 colonoscopies (95.8%) were complete examinations to the cecum. The mean interval between surveillance colonoscopies was 2.71 years (range, 0.27–36.8). By chart review, 282 patients (74.5%) had chart-documented adherence or less than 3-year intervals, on average, between colonoscopies. More detailed demographic data have been reported in our 2 previous studies with the same population of patients.8,10 In all, 353 patients were included when creating the Colonoscopy SE scale, and 366 were included in the Top Five and Highly Certain SE Scales. Mean, range, and variance are included for all scale items in Table 1. All 3 SE scales (Colonoscopy SE Scale, Top Five SE Scale, and Highly Certain SE Scale) correlated with chart-documented adherence (P , 0.001). All 3 SE scales also correlated with increasing age (P , 0.01) and retirement status (P , 0.01). In our previous article, we examined categories of reasons why patients do not adhere to surveillance colonoscopies. These categories included logistics, procedure problems, health perceptions, stress, prep issues, money/insurance, and misinformation. All 3 SE scales correlated negatively with patients reporting that they missed colonoscopies because of misinformation, logistics, health perceptions, stress, procedure problems, and prep issues (P , 0.01). We included the validated Short Form Inflammatory Bowel Disease Questionnaire (SIBDQ) in our large patient questionnaire.15 The SIBDQ is a simple, 10-item questionnaire that can be easily scored and interpreted by clinicians. The SIBDQ measurement of health-related quality of life in patients with IBD provides results parallel to those obtained with the full 32-item IBDQ.16 In this study, all 3 SE scales correlated positively with quality of life (P , 0.01). Given that adherence to surveillance colonoscopy is such an important part of IBD treatment, we sought to develop a model that would predict which patients were more or less
High SE Predicts Colonoscopy Adherence in IBD
likely to adhere. SE correlated highly with adherence, thus serving as a foundation for our model. Our larger IBD questionnaire and chart review collected demographic information, colon cancer risk perception, clinical disease extent and activity, sources of information about IBD, patients’ feelings about IBD and colon cancer, categories of reasons for nonadherence, quality of life, perception of doctor messages, and comorbidities. For identifying other variables for inclusion in our model, we used factor analysis to associate groups of related variables and to create single measures of relevant phenomena. Initial analysis to recognize potential predictors of adherence was performed using adherence and nonadherence group comparisons for continuous factor scores and variables and nonparametric tests for categorical variables. Correlations were assessed among all potential factors and variables for significance of confounding. Variables that correlated with adherence but did not correlate with each other were included in our logistic regression model. All 3 SE scales correlated positively with adherence and were used in 3 separate models with the following 2 variables entering each model: patients reporting a need for surveillance at incorrect intervals (negative correlation) and the extent to which patients reported using sources of information that are nonmedical people (e.g., friends, family, and other patients with IBD rather than physicians) (negative correlation). In an initial step, we forced a count of patients’ locations of disease to enter the model, because this predictor represented the initial physical state that may have precipitated any subsequent health-related knowledge or behavior (Table 3). Controlling for count of disease locations and taking all of the above variables into account in our model, we could predict adherence to surveillance colonoscopy with 74% certainty (Table 4). In our 3 separate adherence models, each of the 3 SE scales proved useful. To decrease the number of questions necessary to assess SE, we recommend using one of the two 8-question versions of the SE scales (Top Five or Highly Certain). In the context of seeing patients in the IBD clinic, we recommend scoring the questionnaire using the Highly Certain method. Those patients who score below 10 (“Highly Certain Can Do”) on 5 or more of the 8 items would be candidates for educational or psychological intervention.
DISCUSSION SE is understood to be an individual’s perception that he or she is likely to attain a specific goal; as a consequence, it must focus on a particular area of functioning. Although people might have high levels of SE regarding 1 realm of their personal performance, such as their ability to complete tasks at their jobs, they may harbor much lower SE when considering their attainment of health-related goals. The stronger the sense of a patient’s taskspecific SE, the greater the patient’s perseverance will be and the higher the likelihood that this given activity will be performed successfully. In light of the task-specific nature of any SE measurement, we must consider the targeted set of beliefs to be www.ibdjournal.org |
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TABLE 3. Frequencies of Outcome and Predictor Variables from Logistic Regression Models Colonoscopy SE Scale Top Five SE Scale and Highly Certain SE Scale (n ¼ 353 for scale; n ¼ 350 for model) (n ¼ 366 for scales; n ¼ 362 for models) On average, fewer than 3 years between colonoscopies No Yes Total Number of disease locationsa 2 3 4 5 6 7 8 Total Cases deleted from model Total scale creation cases Believed 3 or more years between scopes is recommended (or Did not know/Was not told) No Yes Total Scale: information sources are nonmedical peopleb Scale score 3 4 5 6 7 8 9 Total
Frequency 89 261 350 Frequency 29 58 82 64 79 30 8 350 3 353
Percent 25.4 74.6 100.0 Percent 8.3 16.6 23.4 18.3 22.6 8.6 2.3 100.0 Missing
Frequency 91 271 362 Frequency 29 60 84 67 80 33 9 362 4 366
Percent 25.1 74.9 100.0 Percent 8.0 16.6 23.2 18.5 22.1 9.1 2.5 100.0 Missing
Frequency 295 55 350
Percent 84.3 15.7 100
Frequency 303 59 362
Percent 83.7 16.3 100.0
Frequency 133 78 73 54 7 2 3 350
Percent 38.0 22.3 20.9 15.4 2.0 0.6 0.9 100.0
Frequency 140 78 75 55 9 2 3 362
Percent 38.7 21.5 20.7 15.2 2.5 0.6 0.8 100.0
Locations are ileum, cecum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum, and anus. At least one third or more of colon is involved in all patients. a Three types of nonmedical people were included: family, friends, and other patients with CD or UC. b Three-point scoring per item: “I have not used” ¼ 1; “I have used this source sometimes” ¼ 2; “I have used this source extensively” ¼ 3. Additive scale created, with Cronbach’s a of 0.598.
assessed for a relevant statistical construct. In our study, we used a specifically designed SE questionnaire to determine which patients had high SE for completing the colonoscopy process, and our instrument concentrated on a validated list of that process’s task components. We then found a positive correlation between our SE scores and the likelihood of adhering to a surveillance colonoscopy. We created a series of logistic regression models that included our SE scales (1 scale per model) to predict which patients with IBD were most likely to adhere to surveillance colonoscopies. Based on our models, patients demonstrating a high SE score on any of our 3 scales (Colonoscopy SE Scale,
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Top Five SE Scale, or Highly Certain SE Scale) were predicted to be more likely to adhere, and patients (1) having the wrong idea regarding when to come in for surveillance colonoscopies or (2) having reported themselves as more often receiving their diseaserelated information from nonmedical people were predicted to be less likely to adhere (P , 0.0001 for all 3 scales). A simple SE questionnaire administered in the gastroenterologist’s office, along with answers to a few additional questions, can help predict adherence at the 74% level. Useful SE assessments must be task-specific instead of overly broad or all encompassing in their scope; thus, generalized
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High SE Predicts Colonoscopy Adherence in IBD
TABLE 4. Logistic Regression Models of Adherence to Colonoscopy Surveillance Recommendations
Model 1: Included 20-item scale (n ¼ 350)a Constant No. disease locations Colonoscopy SE Scale Wrong idea regarding colonoscopy adherence interval Use of nonmedical people as information sources Model 2: Included 8-item scale, scale items recoded to top 5 points of scale (n ¼ 362)b Constant No. of disease locations Top Five SE Scale Wrong idea regarding colonoscopy adherence interval Use of nonmedical people as information sources Model 3: Included 8-item scale, only “highly certain” responses tallied (n ¼ 362)c Constant No. disease locations Highly Certain SE Scale Wrong idea regarding colonoscopy adherence interval Use of nonmedical people as information sources
95% CI for Odds Ratio Odds (Lower–Upper)
b
SE
Significance (P)
21.553 0.225 0.018 21.944 20.252
1.140 0.094 0.006 0.335 0.104
0.173 0.016 0.001 ,0.001 0.016
1.253 1.018 0.143 0.777
(1.043–1.505) (1.007–1.029) (0.074–0.276) (0.633–0.953)
20.254 0.207 0.060 21.899 20.237
0.778 0.092 0.016 0.326 0.103
0.744 0.024 ,0.001 ,0.001 0.021
1.230 1.062 0.150 0.789
(1.027–1.472) (1.030–1.095) (0.079–0.284) (0.644–0.965)
0.689 0.207 0.183 21.876 20.234
0.673 0.091 0.051 0.325 0.103
0.306 0.024 ,0.001 ,0.001 0.023
1.230 1.201 0.153 0.791
(1.028–1.472) (1.086–1.328) (0.081–0.289) (0.647–0.968)
R ¼ 0.174 (Cox & Snell), 0.257 (Nagelkerke). Model x2(4) ¼ 67.087; P , 0.0001. R ¼ 0.173 (Cox & Snell), 0.256 (Nagelkerke). Model x2(4) ¼ 68.745; P , 0.0001. c 2 R ¼ 0.169 (Cox & Snell), 0.250 (Nagelkerke). Model x2(4) ¼ 66.938; P , 0.0001. a 2
b 2
SE scales were not worthwhile for our predictive modeling effort. In this study, we have developed the first SE questionnaire that can be used uniquely in our population of patients with IBD for the specific issue of undergoing colonoscopies. Unlike the general population without IBD, our patients must undergo regular colonoscopies at short intervals for the rest of their lives. Because our patients are often diagnosed at a young age, this could mean 20 to 30 colonoscopies in a lifetime. Patients with high SE scores on our scales are more likely to demonstrate mastery of the colonoscopy experience and are thus more likely to complete it successfully and return on time for future colonoscopies. Our questionnaire could certainly be modified and tested in the general population to see which patients may need educational counseling before scheduling a colonoscopy for the appropriate surveillance of non-IBD populations. Another correlate with SE in our study was health-related quality of life. The higher a person’s health-related quality of life, the higher his or her SE. This reasonably follows because patients with better health are more likely to tolerate the colonoscopy process. Patients who gave reasons for missing a colonoscopy that included the categories of misinformation, logistics, health perceptions, stress, procedure problems, and prep issues had lower SE scores, which is not surprising becasue offering such
reasons or excuses would indicate unsuccessful mastery and therefore low SE for the colonoscopy process. Perceived SE has been investigated thrice before to assess its role in the management of IBD in general. Keefer at al17 developed and validated an IBD-specific SE scale to evaluate how well patients were coping with stress and emotions, managing medical care, managing symptoms of disease, and maintaining remission. Zijlstra et al18 developed a questionnaire to look at SE in adolescents with IBD and Izaguirre et al19 looked qualitatively at SE in adolescents and young adults with IBD. In other non-IBD studies, perceived SE has been shown to affect physical, psychological, and social functioning in patients with cancer, multiple sclerosis, and diabetes.20–22 High SE has been linked to success in health screening for breast cancer,23 decreasing fear of childbirth and decreasing preference for cesarean section,24 smoking cessation,25 and prevention of eating disorders in adolescents.26 Because the first study to develop an SE scale specifically targeted towards patients with IBD who require surveillance colonoscopies, the strengths of our study are the high number of patients enrolled, the high response rates to the questionnaires, and the extensive analysis of all the interrelated questions and responses. To participate, the patients all visited university-based practices, which suggests a study weakness in that responses www.ibdjournal.org |
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found in private practice may not be similar. Additionally, the sample was predominantly white, was one-third Jewish (higher than average for patients with IBD), and had attained higher levels of education and higher levels of household income on average. Another factor that might affect adherence is that all patients in Massachusetts are mandated to have health insurance; thus the patients in this study might have had greater medical access than others in different states, consequently increasing their adherence. An additional factor that might have influenced SE is any colonoscopy preparation teaching undertaken by doctors and office staff. In general, patients received only the formal set of preparation instructions by e-mail or on paper and scheduled the appointment by e-mail or phone. There was no formal written, phone, or in-person colonoscopy education or teaching in any of the practices. In our previous study, we measured doctor message about colonoscopy by formally validating our Doctor Told Scale in this same population of patients.10 Although our Doctor Told Scale did correlate with chart-reported adherence (P , 0.01), it did not correlate with SE. Thus, although doctors may have spoken with patients about the colonoscopy procedure, we did not find that this communication was associated with improved SE. Patients who reported for more frequent colonoscopies had higher SE scores, and patients with a lower average time between screenings had a higher score on all 3 SE scales (P , 0.01). This aligns with social cognitive theory, which states that the more frequently a person successfully performs a task, the better his or her potential for SE enhancement. In summary, we demonstrate that high SE can predict adherence to surveillance colonoscopies in patients with IBD. We have validated a SE efficacy questionnaire specifically designed for patients with IBD undergoing surveillance colonoscopies, and we propose that it can be used in the IBD clinic to predict which patients will need educational intervention. In addition, we developed an adherence model, of which SE is a critical component, and this model can be used to predict adherence at the 74% level.
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