273
Pain, 51 (1992) 273-280 0 1992 Elsevier Science Publishers B.V. All rights reserved 0304-3959/92/$05.00
PAIN 02158
Chronic pain coping measures: individual vs. composite scores Mark P. Jensen a,c,Judith A. Turner a,b,cand Joan M. Roman0 b,c Departments of a Rehabilitation Medicine (RI-30) and b Psychiatry and Behavioral Sciences (RFIO), University of Washington School of Medicine, Seattle, WA 98195 (USA) and ’ Multidisciplinary Pain Center (RC-95), University of Washington Medical Center, Seattle, WA 98195 (USA)
(Received 10 February 1992, revision received 25 June 1992, accepted 26 June 1992)
Differences in the use of coping strategies have been hypothesized to explain some of the variation Summary in adaptation among chronic pain patients. Investigators often assess coping using composite indices of different coping strategies. Although the use of composite measures has advantages, it may obscure the importance of specific coping strategies as they relate to functioning. This study compared composite with individual coping scale scores in the prediction of adjustment among chronic pain patients. One hundred and forty-one patients completed the Coping Strategies Questionnaire (CSQ) and 2 measures of adjustment (Sickness Impact Profile (SIP) and the Beck Depression Inventory (BDI)). The scales and ratings of the CSQ were factor analyzed to create composite measures, and the ability of the composite scores and individual scales to predict adjustment was compared. The results indicated that the individual scales provided more information than the composite measures regarding the relationship between coping and adjustment to chronic pain. The results also suggested that individual scale scores may be more useful than composite scores in identifying the conditions under which coping efforts have their greatest effects on adjustment. Key words: Coping strategies; Chronic Depression Inventory
pain; Coping Strategies
Introduction Chronic pain sufferers use a variety of methods to cope with pain and associated problems. Differences in coping styles and strategies have been hypothesized to explain some of the variation in adaptation observed among those who experience chronic pain (see reviews by Turner 1991 and Jensen et al. 1991a). Unfortunately, methodological problems limit the conclusions that can be drawn from research examining the relationships between coping and adjustment to chronic pain (Jensen et al. 1991a). One such problem concerns the assessment of coping. Most commonly, coping has been measured in terms of composite dimensions rather than individual coping strategies. For example, the Vanderbilt Pain
Correspondence to: Mark P. Jensen, Department of Rehabilitation Medicine (RJ-30), University of Washington School of Medicine, Seattle, WA 98195, USA.
Questionnaire;
Sickness Impact
Profile;
Beck
Management Inventory (Brown and Nicassio 1987) combines numerous coping strategies into 2 composite measures labeled ‘active’ and ‘passive’ coping. Similarly, the coping subscales and control ratings from the Coping Strategies Questionnaire (CSQ) (Rosenstiel and Keefe 1983) are usually combined by factor analysis to produce 2 or 3 composite measures of coping. These factor scores are then used in subsequent analyses to examine relationships between coping and adjustment (Rosenstiel and Keefe 1983; Gross 1986; Turner and Clancy 1986; Keefe et al. 1987a,b, 1990a,b,c; Hagglund et al. 1989; Parker et al. 1989; Spinhoven et al. 1989; Beckham et al. 1991). The use of composite measures of pain coping has several advantages (Jensen et al. 1991a). Composite scores can increase one’s ability to interpret the results of analyses when the individual scores are highly correlated (Tabachnick and Fidel1 1983). By increasing the number of items in the measure, composite scores can also increase the reliability of the assessment procedure. Furthermore, composites can reduce the number
274
of statistical tests performed in any one study, thus reducing the chances of type-1 errors in research. Because a high number of predictors with too few subjects can lead to unreliable results (Tabachnick and Fidel1 1983) a reduction in the number of coping measures makes it possible for researchers to examine the relationship between coping and adjustment in relatively small samples of chronic pain patients. Finally, composite scores may be used to identify overriding dimensions of coping that may impact treatment effectiveness. For example, ‘active’ capers may respond better to direct instruction and skill building, whereas ‘passive’ capers may respond better to family or environmental interventions. Composite measures, like the Vanderbilt Pain Management Inventory (Brown and Nicassio 1987) are necessary to identify such groups of patients. However, the exclusive use of composite measures may obscure the importance of specific pain coping strategies as they relate to functioning. For example, in factor analyses of the CSQ, a factor that frequently emerges has been labeled ‘Pain Control and Rational Thinking’. This composite usually includes the Catastrophizing subscale and 2 control ratings (ability to control pain and ability to decrease pain). ’ This factor is associated consistently with measures of physical and psychological functioning (Rosenstiel and Keefe 1983; Keefe et al. 1987a,b, 1990a,b,c; Parker et al. 1989; Beckham et al. 1991). Those patients who report that they avoid catastrophizing thoughts and believe they can control pain report higher levels of functioning than those patients who endorse catastrophic thinking and the belief that they cannot control pain. Although this research supports the potential importance of this composite measure as a predictor of adjustment, it does not allow one to determine if catastrophizing and control beliefs contribute equally to the prediction of adjustment. In factor analyses, the other CSQ scales tend to load either as a single factor (often labeled ‘Coping Attempts’) or form two additional factors. However, rarely does any factor that does not contain either the Catastrophizing scale or the control ratings predict adjustment (Jensen et al. 1991a). Although this is consistent with the hypothesis that the other subscales of the CSQ do not assess coping responses important to adjustment, it is possible that the use of composite scores has obscured potentially significant relationships between individual CSQ coping scores and adjustment. Evidence supporting such associations comes from
’ This factor is usually labeled ‘Pain Control and Rational Thinking’ when the Catastrophizing subscale loads negatively and the control ratings load positively on it. The opposite pattern of loadings is often labeled ‘Helplessness’.
several studies that examined individual CSQ subscales. In one such study, Keefe and Williams (1990) found 3 subscales (Coping Self-Statements, Catastrophizing, and Increasing Activity Level), as well as the 2 control ratings, to be associated with psychological functioning in a group of chronic pain patients. Sullivan and D’Eon (1990) controlled for all other CSQ scales and ratings (by entering them simultaneously in a regression equation), as well as demographic and pain-related variables, and found that only the Catastrophizing subscale predicted depression in a group of chronic low back and neck pain patients. Finally, Jensen and Karoly (1991) found that 3 CSQ subscales (Ignoring Pain, Coping Self-Statements, and Increasing Activity) were associated positively with psychological functioning. Three subscales (Ignoring Pain, Diverting Attention, and Coping Self-Statements) were associated positively with activity level, but only for patients reporting relatively low levels of pain. Although this research suggests that the use of individual coping scales may shed more light on the coping-adjustment relationship than the use of composite measures, no study has compared the predictive ability of composite scores versus individual scores in the same sample of chronic pain patients. The study by Jensen and Karoly (1991) also points to the need to examine moderating factors in the relationship between coping strategies and adjustment to chronic pain. Potentially important moderating variables include pain intensity (Affleck et al. 1987; Jensen and Karoly 1991) and duration of pain (Jensen and Karoly 1992). There are several reasons to examine patient-reported pain intensity as a moderating variable. First, it is possible that patients’ perceptions of pain intensity may act as a ‘3rd variable’ that can influence both coping efforts (patients with a higher level of perceived pain may make more efforts to cope) and functioning (patients with a higher level of perceived pain may function less well than those with lower levels). Second, our clinical experience suggests that patients reporting relatively low levels of pain intensity are more likely to report that certain coping strategies, such as relaxation and ignoring of pain, are beneficial. Finally, previous research supports the potential moderating influence of pain intensity on the relationship between the use of specific coping strategies and functioning (Jensen and Karoly 1991). Pain. duration may also influence the relationship between coping and adjustment. Theoreticians have argued that individuals tend to use coping strategies when they perceive themselves to be under the greatest threat (cf., Wills 1981). We would anticipate that chronic pain may be perceived as less threatening, on average, after an individual has experienced it for a number of years and develops strategies for coping.
215
Thus, it is likely that coping strategies are used more often, and possibly more effectively, earlier on in the development of chronic pain. Empirical support of this hypothesis comes from research that indicates that the use of cognitive coping strategies are more closely associated with positive psychological functioning among individuals who have experienced chronic pain for a relatively short duration (Jensen and Karoly 1992). The primary purpose of this study was to compare the utility of composite scores versus individual coping scale scores in the prediction of adjustment. The study also attempted to replicate the interactions found previously (Jensen and Karoly 1991) between some of the CSQ-assessed coping strategies and pain intensity in the prediction of physical functioning, and to explore the potential moderating effects of pain duration on the coping-adjustment relationship.
Method Subjects The sample was obtained from patients who were admitted to an Inpatient Multidisciplinary Pain Program over a 22-month period (November 1988 to August 1990) and who were eligible to participate in a larger study examining predictors of successful treatment (Jensen et al. 1991bl. Subjects were eligible to participate if they were between the ages of 18 and 65 years (one of the outcome variables was return to work, and this age group was considered to be the most likely to have this as a treatment goal), could read and write English, and did not have evidence of dementia or brain injury. Of the 190 patients who were admitted for treatment, 170 were eligible for the study, and 141 of these agreed to participate. The average age of the study participants was 41 years, and the average duration of their pain was 5.4 years (range: 3 months-40 years). Fifty-six percent of the subjects were women. Seventy-one percent were married or living with a significant other. The rest reported that they were divorced (13%1, had never been married (7%), were separated from their spouse (8%), or were widowed (1%). Sixty-seven percent reported that they were not working due to pain. The others reported that they were working (16%), homemakers (60/o),not working for reasons other than pain (6%1, retired (4%1, or going to school (1%). The majority of the subjects were Caucasian (92%). The rest reported their race as Hispanic (3%1, Native American (2%), Asian cl%), African-American (1%) or ‘other’ (1%). Most of the subjects (76%) reported that they had at least a high school education or general equivalency diploma. The most frequent primary site of pain was the low back (43%). Other primary sites included leg (14%), head (14%), neck (lo%), shoulder/arm (lo%), abdomen (5%), upper back (lo/o), pelvis (I%), anal/genital region (lo/o), and multiple primary sites (1%). The 141 subjects who agreed to participate were compared with the 29 who declined participation through a series of t tests (for age and duration of pain problem) and chi-square analyses (for educational level, race, pain site, marital status, and employment status). No significant differences emerged between the 2 groups of patients.
Measures Pain intensify. Pain intensity was assessed using a lOl-point Numerical Rating Scale (NRS-1011. Subjects were asked to indicate the average intensity of their pain during the past 2 weeks from 0 (no
pain) to 100 (pain as bad as it could be). The NRS-101 has been demonstrated to be a valid measure of pain intensity through its strong association with a linear combination of several pain intensity measures (Jensen et al. 1986, 1989). Coping Strategies Questionnaire (CSQ). The CSQ (Rosenstiel and Keefe 1983) was designed to assess 6 cognitive coping responses to pain (diverting attention, coping self-statements, praying or hoping, reinterpreting pain sensations, catastrophizing, and ignoring pain) and 1 behavioral response (increased behavioral activities). The CSQ also contains 2 items relating to patients’ perceived ability to control and decrease pain. Sickness Impact Profile (SIP). The SIP (Bergner et al. 1981) is a 136-item self-report checklist that assesses the impact of illness on 12 categories of daily functioning. In addition to an overall score, the SIP yields composite physical and psychosocial dysfunction scores. It has demonstrated good to excellent reliability and validity as a measure of dysfunction in a number of samples of chronic pain patients (Follick et al. 1985; Roman0 et al. 1988). Beck Depression Inventory (Bol). The BDI (Beck et al. 1979) is a 21-item self-report measure that requires subjects to report on the incidence of various symptoms of depression. It has demonstrated excellent reliability and validity (Beck et al. 19881, as well as ability to discriminate depressed from non-depressed pain patients (Turner and Roman0 1984).
Procedure Patients who were admitted to the Inpatient Multidisciplinary Chronic Pain Treatment Program at the University of Washington Medical Center were invited to participate in a program evaluation (Jensen et al. 1991b). Those who agreed to participate were asked to complete the NRS-101 and the CSQ within 2 days after admission. The SIP and the BDI are administered to all patients admitted to the Inpatient Pain Management Program as part of their admission assessment. Completed SIPS and BDIs were available for 128 and 117 of the subjects in this study, respectively.
Results Overview of data analyses
The 7 scales and 2 control ratings from the CSQ were subjected to a principal factors analysis using an oblique rotation. Principal factors analysis (PFA) was chosen over other factor analytic procedures because PFA provides a solution uncontaminated by the error variance of the measures. This procedure is appropriate when the goal of the analysis is to understand the hypothetical dimensions embedded in data (Tabachnick and Fidel1 1983). An oblique rotation was selected over orthogonal procedures because it was expected that the resulting coping factors would be related. Correlational analyses were then performed to examine the degree of overlap among the individual CSQ scales. Close associations between the individual CSQ scales would suggest that they do not assess distinct coping strategies and would argue more strongly for combining them into composite measures for statistical analyses (Tabachnick and Fidel1 1983). Following the correlational analyses, a series of multiple regression analyses were performed to determine the extent to which the CSQ factor scores and the individual CSQ
27h
scales and ratings make unique contributions to the prediction of the SIP Physical Dimension, SIP Psychosocial Dimension, and BDI scores. Factor analysis
Two factors emerged from the factor analysis of the CSQ scores, explaining 55% of the variance. The lst, 2nd, and 3rd eigenvalues that emerged were 3.15, 1.84, and 0.90, respectively. The 1st factor was made up of the majority of the CSQ coping scales (Ignore Pain: loading = 0.74; Divert Attention: 0.72; Coping SelfStatements: 0.71; Increase Activities: 0.70; and Reinterpret Pain Sensations: 0.54). This factor is very similar to the ‘Coping Attempts’ factor identified by Keefe et al. (1987a) and Parker et al. (1989) in their 2-factor solutions of the CSQ scales. The 2nd factor was similar to the ‘Helplessness’ factor identified by a number of researchers (RosenstieI and Keefe 1983; Turner and Clancy 1986; Keefe et al. 1990~1, and consisted of the control ratings (Control over pain: loading = -0.63; Ability to decrease pain: - 0.53); The Catastrophizing scale (0.62) and Praying and Hoping (0.39). The 2 factors demonstrated a weak relationship to each other (Y = -0.10). Correlational analyses
In order to determine the degree of overlap between the CSQ subscales and to examine the first-order relationships between the CSQ scales and the adjustment measures, correlation analyses were performed. Of the 36 correlations computed between pairs of individual CSQ scales, only 4 indicated a large degree of overlap (i.e., r = 0.50 or more>. These included the correlations between Ignore Pain and Reinterpreting Pain scales (r = 0.541, the Ignore Pain and Coping Self-Statement scales (r = 0.661, the Increase Activities and Coping Self-Statement scales (r = 0.531, and the Increase Activities and Divert Attention scales (r = 0.61). Qverail, however, the results indicated little overlap between the CSQ scales. The median correlation coefficient between all scales was 0.22, indicating that each scale accounted for less than 5% of the variance in the other scaIes on average. The correlations between the CSQ scores (including both the individual scaies and the composite factor scores) and measures of adjustment are presented in Table I. As can be seen, the CSQ Helplessness composite factor demonstrated a moderate relationship to both the SIP Psychosocial Dysfunction and the BDI scores (rs = 0.31 and 0.39, both Ps < 0.001, 2-tailed tests), but the Coping Attempts factor was not related significantly to any adjustment measure. Only 1 individual CSQ scale score was associated significantly with the SIP Physical Dysfunction score. The Praying and Hoping scale demonstrated a weak positive relationship to physical dysfunction (r = 0.18, P < 0.05, 2-tailed
TABLE
I
CORRELATIGN COEFFICIENTS BETWEEN THE ADJUSTMENT MEASURES AND THE CSQ FACTOR SCORES, SCALES AND RATINGS CSQ = Coping Strategies Questionnaire; file; BDI = Beck Depression Inventory. CSQ measure
FdCtOr
SIP Physical
SIP = Sickness
SIP Psychosocial
Impact
Pro-
BDI
scores
Coping Attempts
0.09
0.08
Helplessness
0.07
0.31 ***
(1.10 0.14 0.1n 0.03 0. IX * 0.14 - (1.04
0.09 0.25 * * 0.40 * * * 0.00 0.14 0.04 - 0.04
- 0.08 0.04 0.53 *** -0.12 0.10 - 0.03 -0.15
-0.19 * - 0.09
-0.26 -0.16
- 0.08 0.39 * * *
Scale scores
Divert Attention Reinterpret Pain Catastrophizing Ignore Pain Pray and Hope Coping Self-Statements Increase Activities Ratings Ability to Control Pain Ability to Decrease Pain -
0.01 0.03
**
* P < O.05; ** P < 0.01; * ** P < 0,001.
test). Reinterpreting Pain Sensations and Catastrophizing were both related positively to the SIP Psychosocial Dysfunction scale (rs = 0.25 and 0.40, Ps < 0.01 and 0.001, respectively, 2-tailed tests), and sense of control over pain was associated negatively with SIP Psychosocial Dysfunction (r = -0.19, P < 0.05, 2-tailed test). BDI scores correlated with Catastrophizing (r = 0.53, P < 0.001, 2-tailed test) and the Pain Control Rating (r = -0.26, P < 0.01, Z-tailed test). Six of the CSQ individual measures demonstrated no significant relationship to the adjustment measures. Multiple regression analyses
A series of 6 regression analyses were performed to determine the relationship between the CSQ scales and the 3 adjustment measures (SIP Physical, SIP Psychosocial, and BDI) while controlling for demographic variables (age, gender), pain-related variables (duration of pain, pain intensity, pain site), and each CSQ measure. Site of pain was defined as low back versus other because the low back pain group was the largest subgroup defined by single pain site (43%). The major predictors (coping measures) were entered in the 3rd step as a block. Interactions of the predictors with the pain-related (moderator) variables were entered in the 4th step in a stepwise fashion (that is, only those that were significant were entered into the equations) using the procedure outlined by Cohen and Cohen (1983) to examine whether pain intensity or duration of the pain problem moderate the relationship between coping and adjustment. Three analyses were conducted to predict the adjustment measures using the CSQ
277
TABLE II RESULTS OF THE MULTIPLE REGRESSION ANALYSES PREDICTING ADJUSTMENT FROM CSQ FACTOR SCORES SIP = Sickness Impact Profile. Step and variable
Total
Change
R2
R2
Beta to enter
F
Criterion: SIP Psychosocial Dysfunction
1 Demographics Age Gender 2 Pain-related variables Pain intensity Pain site Pain duration 3 CSQ factor scores Coping Attempts Helplessness
0.02
0.02
1.37 0.03 -0.14
0.06
0.04
1.86 - 0.01 - 0.02 -0.21 *
0.20
0.13
9.96 * * * 0.19 * 0.38 * * *
Criterion: Beck Depression Inventory
1 Demographics Age Gender 2 Pain-related variables Pain intensity Pain site Pain duration 3 CSQ factor scores Coping Attempts Helplessness
0.01
0.01
0.47 0.07 0.06
0.06
0.06
2.21
0.10 0.01 -0.22 0.22
0.15
*
10.50 *** 0.00 0.40 * * *
* P < 0.05; * * P < 0.01; * * * P < 0.001.
ing relatively low levels of pain (r = 0.171, but was related moderately to physical dysfunction among those reporting medium (r = 0.41, P < 0.01, 2-tailed test) and high levels of pain intensity (r = 0.51, P < 0.001, 2tailed test). Both Reinterpreting Pain Sensations and Catastrophizing made independent contributions to the prediction of SIP Psychosocial Dysfunction when controlling for demographic variables and pain-related variables. In addition, a significant Catastrophizing x Pain Duration interaction emerged in the analysis predicting SIP Psychosocial Dysfunction. To examine this interaction, the subjects were divided into 3 equal groups based on pain duration. Correlations between Catastrophizing and SIP Psychosocial Dysfunction for subjects presenting with pain of relatively short (3 months-2.3 years), medium (2.3-5.2 years), and long (5.3-38.8 years) duration indicated strong relationships among patients with short and medium pain duration (rs = 0.50 and 0.51, Ps < 0.01 and 0.001, respectively, 2-tailed tests), and a non-significant relationship between Catastrophizing and Psychosocial Dysfunction among patients with a long history of pain. The only individual CSQ measure that predicted depression (as measured by the BDI) was the Catastrophizing scale. No interactions of the individual CSQ scales and pain intensity or pain duration were significant in the prediction of depression.
Discussion
factor scores (shown in Table II>, and 3 using the CSQ individual scores (shown in Table III). CSQ composite scores as predictors of adjustment. Both Helplessness and Coping Attempts demonstrated positive relationships to the SIP Psychosocial Dysfunction score. Only the Helplessness factor was associated with the BDI. Neither CSQ factor score was related to the SIP Physical Dysfunction score, and neither interacted with pain intensity or pain duration in the prediction of adjustment. CSQ individual scores as predictors of adjustment. Although no individual CSQ scale demonstrated a significant direct relationship to the SIP Physical Dysfunction score when demographic and pain-related measures were controlled, a significant Coping SelfStatements x Pain Intensity interaction did emerge. In order to examine this interaction more closely, subjects were divided into 3 equal groups based on their pain intensity ratings. Separate correlations were then computed between Coping Self-Statements and SIP Physical Dysfunction for those reporting low (lo-45 on a lOl-point scale), medium (50-651, and high (70-100) levels of pain intensity. The results indicated that the endorsement of Coping Self-Statements was unrelated to SIP Physical Dysfunction for those subjects report-
The primary purpose of this study was to compare the utility of composite versus individual coping measures in the prediction of adjustment among chronic pain patients. The results underscore several important differences between the 2 scoring methods. First, the CSQ factor scores were not superior to individual scale scores in predicting adjustment in this study. That is, the ability to predict outcome was not improved with the use of composite measures. Second, the use of individual scores appears to provide a better understanding of the specific coping strategies that best predict adjustment. For example, even though the Helplessness factor was associated with both measures of psychological functioning, only in the analyses using the individual CSQ scores was it apparent that this relationship was primarily due to Catastrophizing, and not to the control appraisals. Similarly, although the Coping Attempts factor predicted Psychosocial Dysfunction, individual scale analysis revealed that this relationship was mostly due to Reinterpreting Pain Sensations. The present analyses suggest that, of the individual CSQ measures examined, Catastrophizing and Reinterpreting Pain Sensations appear to be the responses that were associated directly with adjust-
278 TABLE
III
TABLE
RESULTS OF PREDICTING SCORES SIP = Sickness
THE MULTIPLE ADJUSTMENT
Impact
REGRESSION FROM CSQ
ANALYSES INDIVIDUAL
Profile.
Step and variable
Total
Change
R2
R=
F
0.02
1.20
Criterion: SIP Physical Dysfunction 1 Demographics 0.02 Age Gender 2 Pain-related variables Pain intensity Pain site Pain duration 3 CSQ individual scores Coping Self-Statements Pray and Hope Reinterpret Pain Sensations Catastrophize Divert Attention Increase Activities Ignore Pain Ability to Control Pain Ability to Decrease Pain 4 Interaction Coping Self-Statements X Pain Intensity
Total
Change
R2
n
Increase Activities Ignore Pain Ability to Control Pain Ability to Decrease Pain
Beta to enter
Beta to enter -0.22 0.02 - 0.03 - 0.06
* P < 0.05; * * P < 0.01; * * * P < 0.001.
0.12
0.10
4.76 * * 0.08 -0.24 ** -0.18 *
0.08
0.20
1.24 0.20 0.12 0.15 0.10 0.08 -0.17 -0.16 0.05 0.02
0.24
0.04
5.60 *
0.02
1.37
-0.81
*
0.03 -0.14 0.06
0.04
1.86 - 0.01 - 0.02 -0.21 *
0.29
0.21
3.91 * * * 0.01 0.00 0.23 * 0.38 *** 0.10 - 0.06 - 0.02 - 0.07 0.01
0.31
0.03
4.32 *
Criterion: Beck Depression Imentory 1 Demographics 0.01
0.01
0.47
Age Gender 2 Pain-related variables Pain intensity Pain site Pain duration 3 CSQ individual scores Coping Self-Statements Pray and Hope Reinterpret Pain Sensations Catastrophize Divert Attention
Step and variable
0.14 - 0.01
Criterion: SIP Psychosocial Dysfunction 1 Demographics 0.02 Age Gender 2 Pain-related variables Pain intensity Pain site Pain duration 3 CSQ individual scores Coping Self-Statements Pray and Hope Reinterpret Pain Sensations Catastrophize Divert Attention Increase Activities Ignore Pain Ability to Control Pain Ability to Decrease Pain 4 Interaction Catastrophize x Pain Duration
III (continued)
-0.32
*
0.07 0.06 0.06
0.06
2.21 0.10 0.01 -0.22 *
0.38
0.31
5.71 * ** 0.15 -0.08 0.03 0.54 * * * 0.02
ment. These results need to be cross-validated and then tested using experimental designs to determine whether causal relationships exist between these responses and dimensions of adjustment. Further evidence supporting the usefulness of individual scale scores comes from the significant interactions that emerged in the prediction of adjustment. Although no interactions were found using the composite measures, 2 interactions emerged when the individual scores were used. This finding suggests that the use of individual scale scores may lead to a better understanding of the more complex relationships that can exist between coping and adjustment. One of the interactions found was inconsistent with results of previous research. In the present study, the use of coping self-statements was related positively to physical dysfunction among those who reported higher levels of pain, whereas in previous research coping self-statements were related negatively to physical dysfunction, but only among subjects reporting relatively low levels of pain intensity (Jensen and Karoly 1991). There are several possible explanations for this discrepant finding. First, there may be differences specific to the pain populations studied. Patients differ across treatment sites (Holzman et al. 1985), and it is possible that unique characteristics of each population may have influenced the findings. Second, the criterion measures differed in the two studies. The use of coping selfstatements may have a different relationship to activity level as assessed by the activity scales of the Multidimensional Pain Inventory (the criterion used in Jensen and Karoly 1991) than to physical dysfunction as assessed by the SIP (the criterion used in the present study), which encompasses other dimensions of functioning such as ambulation, mobility, and body care. Additional studies are needed to replicate and explore further these findings. The interaction found in the present study between the use of catastrophizing and pain duration in the prediction of psychosocial dysfunction is similar to findings of previous research (Jensen and Karoly 1992). In both studies, cognitive responses to pain (catastrophizing in the present study and not making positive comparisons of oneself and one’s situation to other people and situations in Jensen and Karoly’s
279
study (1992)) were more strongly associated with poor psychological functioning among those with pain of a shorter duration. It is possible that cognitive responses have their greatest impact upon psychological adjustment in the first few years following the onset of pain. One limitation of this study is its reliance on self-report measures of coping and adjustment. A replication of the present findings with other measures (including observational measures) of coping and functioning is indicated. Also, given that the study is a cross-sectional correlational design, it is not possible to make causal statements regarding the association between coping strategies and adjustment based on the findings. A third limitation is that the results have unknown generalizability. Because the sample was obtained from a group of patients admitted to an Inpatient Pain Program, the findings may not generalize to other populations of individuals experiencing pain. Also, the pain coping measure used (CSQ) is primarily a measure of cognitive, not behavioral, pain coping strategies. The results might have been different if additional pain strategies had been assessed. Despite these limitations, this study involved the first comparison of composite coping scores to individual coping strategy measures in the prediction of adjustment to chronic pain. Although the results indicate that the use of individual scale scores may be more informative, the use of composites still has merit, and should not be abandoned (see Jensen et al. 1991a). However, when measuring dimensions that may be only weakly to moderately related to one another (as appears to be the case among the subscales of the CSQ), the exclusive use of composites potentially can impede the understanding of how coping relates to adjustment.
Acknowledgements
This research was supported by a National Research Service Award (F32 NS08545) to M.P.J. and a Graduate School Research Fund grant from the University of Washington to J.M.R.
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disability, depression and daily hassles, Behav. Ther., 22 (1991) 113-124. Bergner, M., Bobbitt, R.A., Carter, W.B. and Gilson, B.S., The Sickness Impact Profile: development and final revision of a health status measure, Hlth Care, 19 (1981) 787-805. Brown, G.K. and Nicassio, P.M., The development of a questionnaire for the assessment of active and passive coping strategies in chronic pain patients, Pain, 31 (1987) 53-65. Cohen, J. and Cohen, P., Applied Multiple Regression/Correlation Analysis for the Behavioral Sciences, 2nd edn., Erlbaum, Hillsdale, NJ, 1983. Follick, M.J., Smith, T.W. and Ahern, D.K., The Sickness Impact Profile: a global measure of disability in chronic low back pain, Pain, 21 (1985) 67-76. Gross, A.R., The effect of coping strategies on the relief of pain following surgical interventions for lower back pain, Psychosom. Med., 48 (1986) 229-241. Hagglund, K.J., Haley, W.E., Reveille, J.D. and Alarcon, G.S., Predicting individual differences in pain and functional impairment among patients with rheumatoid arthritis, Arthr. Rheum., 32 (1989) 851-858. Holzman, A.D., Rudy, T.E., Gerber, K.E., Turk, D.C., Sanders, S.H., Zimmerman, J. and Kerns, R.D., Chronic pain: a multiple-setting comparison of patient characteristics, J. Behav. Med., 8 (1985) 411-422. Jensen, M.P. and Karoly, P., Control beliefs, coping efforts and adjustment to chronic pain, J. Consult. Clin. Psychol., 59 (1991) 431-438. Jensen, M.P. and Karoly, P., Comparative self-evaluation and depressive affect among chronic pain patients: an examination of selective evaluation theory, Cogn. Ther. Res., 16 (1992) 297-308. Jensen, M.P., Karoly, P. and Braver, S., The measurement of clinical pain severity: a comparison of six methods, Pain, 27 (1986) 117-126. Jensen, M.P., Karoly, P., O’Riordan, E.F., Bland, E.F., Jr. and Burns, R.S., The subjective experience of acute pain: an assessment of the utility of ten indices, Clin. J. Pain, 5 (1989) 153-159. Jensen, M.P., Turner, J.A., Romano, J.M. and Karoly, P., Coping with chronic pain: a critical review of the literature, Pain, 47 (1991a) 249-283. Jensen, M.P., Turner, J.A., Romano, J.M. and Martinez, J.R., Multidisciplinary treatment of chronic pain: a process analysis. Poster presented at the 10th Annual Meeting of the American Pain Society, New Orleans, LO, 1991b. Keefe, F.J., Caldwell, D.S., Queen, K.T., Gil, K.M., Martinez, S., Crisson, J.E., Ogden, W. and Nunley, J., Osteoarthritic knee pain: a behavioral analysis, Pain, 28 (1987a) 309-321. Keefe, F.J., Caldwell, D.S., Queen, K.T., Gil, K.M., Martinez, S., Crisson, J.E., Ogden, W. and Nunley, J., Pain coping strategies in osteoarthritis patients, J. Consult. Clin. Psychol., 55 (1987b) 208212. Keefe, F.J., Caldwell, D.S., Williams, D.A., Gil, K.M., Mitchell, D., Martinez, S., Nunley, J., Beckham, J.C., Crisson, J.E. and Helms, M., Pain coping skills training in the management of osteoarthritic knee pain: a comparative study, Behav. Ther., 21 (1990a) 49-62. Keefe, F.J., Caldwell, D.S., Williams, D.A., Gil, K.M., Mitchell, D., Robertson, C., Martinez, S., Nunley, J., Beckham, J.C. and Helms, M., Pain coping skills training in the management of osteoarthritic knee pain. II. Follow-up results, Behav. Ther., 21 (1990b) 435-447. Keefe, F.J., Crisson, J., Urban, B.J. and Williams, D.A., Analyzing chronic low back pain: the relative contribution of pain coping strategies, Pain, 40 (1990~) 293-301. Keefe, F.J. and Williams, D.A., A comparison of coping strategies in chronic pain patients in different age groups, J. Gerontol., 45 (1990) 161-165.
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Parker, J.C., Smarr, K.L., Buescher, K.L., Phillips, L.R., Frank, R.G., Beck, N.C. Anderson, S.K. and Walker, SE., Pain control and rational thinking, Arthr. Rheum., 32 (1989) 984-990. Romano, J.M., Syrjala, K., Levy, R., Turner, J.A., Evans, P. and Keefe, F., Overt pain behaviors: relationship to patient functioning and treatment outcome, Behav. Ther., 19 (1988) 191-266. Rosenstiel, A.K. and Keefe, F.J., The use of coping strategies in chronic low back pain patients: relationship to patient characteristics and current adjustment, Pain, 17 (1983) 33-44. Spinhoven, P., Ter Kuile, M.M., Linssen, A.C.G. and Gazendam, B., Pain coping strategies in a Dutch population of chronic low back pain patients, Pain, 37 (1989) 77-83. Sullivan, M.J.L. and D’Eon, J.L., Relation between catastrophizing and depression in chronic pain patients, J. Abnorm. Psychol., 99 (1990) 260-263.
Tabachnick, B.G. and Fidell, L.S., Using Multivariate Statistics, Harper and Row, New York, 1983. Turner, J.A., Coping and chronic pain. In: M. Bond, J.E. Charlton and C.J. Woolfe (Eds.), Pain Research and Clinical Management, Proc. VIth World Congress on Pain, Vol. 4, Elsevier, New York, 1991, 219-227. Turner, J.A. and Clancy, S., Strategies for coping with chronic low back pain: relationships to pain and disability, Pain, 24 (1986) 355-364. Turner, J.A. and Romano, J.M., Self-report screening measures for depression in chronic pain patients, J. Clin. Psychol., 40 (1984) 909-913. Wills, T.A., Downward comparison principles in social psychology, Psychol. Bull., 90 (1981) 245-271.
Pain, 51 (1992) 273-280 0 1992 Elsevier Science Publishers B.V. All rights reserved 0304-3959/92/$05.00
PAIN 02158
Chronic pain coping measures: individual vs. composite scores Mark P. Jensen a,c,Judith A. Turner a,b,cand Joan M. Roman0 b,c Departments of a Rehabilitation Medicine (RI-30) and b Psychiatry and Behavioral Sciences (RFIO), University of Washington School of Medicine, Seattle, WA 98195 (USA) and ’ Multidisciplinary Pain Center (RC-95), University of Washington Medical Center, Seattle, WA 98195 (USA)
(Received 10 February 1992, revision received 25 June 1992, accepted 26 June 1992)
Differences in the use of coping strategies have been hypothesized to explain some of the variation Summary in adaptation among chronic pain patients. Investigators often assess coping using composite indices of different coping strategies. Although the use of composite measures has advantages, it may obscure the importance of specific coping strategies as they relate to functioning. This study compared composite with individual coping scale scores in the prediction of adjustment among chronic pain patients. One hundred and forty-one patients completed the Coping Strategies Questionnaire (CSQ) and 2 measures of adjustment (Sickness Impact Profile (SIP) and the Beck Depression Inventory (BDI)). The scales and ratings of the CSQ were factor analyzed to create composite measures, and the ability of the composite scores and individual scales to predict adjustment was compared. The results indicated that the individual scales provided more information than the composite measures regarding the relationship between coping and adjustment to chronic pain. The results also suggested that individual scale scores may be more useful than composite scores in identifying the conditions under which coping efforts have their greatest effects on adjustment. Key words: Coping strategies; Chronic Depression Inventory
pain; Coping Strategies
Introduction Chronic pain sufferers use a variety of methods to cope with pain and associated problems. Differences in coping styles and strategies have been hypothesized to explain some of the variation in adaptation observed among those who experience chronic pain (see reviews by Turner 1991 and Jensen et al. 1991a). Unfortunately, methodological problems limit the conclusions that can be drawn from research examining the relationships between coping and adjustment to chronic pain (Jensen et al. 1991a). One such problem concerns the assessment of coping. Most commonly, coping has been measured in terms of composite dimensions rather than individual coping strategies. For example, the Vanderbilt Pain
Correspondence to: Mark P. Jensen, Department of Rehabilitation Medicine (RJ-30), University of Washington School of Medicine, Seattle, WA 98195, USA.
Questionnaire;
Sickness Impact
Profile;
Beck
Management Inventory (Brown and Nicassio 1987) combines numerous coping strategies into 2 composite measures labeled ‘active’ and ‘passive’ coping. Similarly, the coping subscales and control ratings from the Coping Strategies Questionnaire (CSQ) (Rosenstiel and Keefe 1983) are usually combined by factor analysis to produce 2 or 3 composite measures of coping. These factor scores are then used in subsequent analyses to examine relationships between coping and adjustment (Rosenstiel and Keefe 1983; Gross 1986; Turner and Clancy 1986; Keefe et al. 1987a,b, 1990a,b,c; Hagglund et al. 1989; Parker et al. 1989; Spinhoven et al. 1989; Beckham et al. 1991). The use of composite measures of pain coping has several advantages (Jensen et al. 1991a). Composite scores can increase one’s ability to interpret the results of analyses when the individual scores are highly correlated (Tabachnick and Fidel1 1983). By increasing the number of items in the measure, composite scores can also increase the reliability of the assessment procedure. Furthermore, composites can reduce the number
274
of statistical tests performed in any one study, thus reducing the chances of type-1 errors in research. Because a high number of predictors with too few subjects can lead to unreliable results (Tabachnick and Fidel1 1983) a reduction in the number of coping measures makes it possible for researchers to examine the relationship between coping and adjustment in relatively small samples of chronic pain patients. Finally, composite scores may be used to identify overriding dimensions of coping that may impact treatment effectiveness. For example, ‘active’ capers may respond better to direct instruction and skill building, whereas ‘passive’ capers may respond better to family or environmental interventions. Composite measures, like the Vanderbilt Pain Management Inventory (Brown and Nicassio 1987) are necessary to identify such groups of patients. However, the exclusive use of composite measures may obscure the importance of specific pain coping strategies as they relate to functioning. For example, in factor analyses of the CSQ, a factor that frequently emerges has been labeled ‘Pain Control and Rational Thinking’. This composite usually includes the Catastrophizing subscale and 2 control ratings (ability to control pain and ability to decrease pain). ’ This factor is associated consistently with measures of physical and psychological functioning (Rosenstiel and Keefe 1983; Keefe et al. 1987a,b, 1990a,b,c; Parker et al. 1989; Beckham et al. 1991). Those patients who report that they avoid catastrophizing thoughts and believe they can control pain report higher levels of functioning than those patients who endorse catastrophic thinking and the belief that they cannot control pain. Although this research supports the potential importance of this composite measure as a predictor of adjustment, it does not allow one to determine if catastrophizing and control beliefs contribute equally to the prediction of adjustment. In factor analyses, the other CSQ scales tend to load either as a single factor (often labeled ‘Coping Attempts’) or form two additional factors. However, rarely does any factor that does not contain either the Catastrophizing scale or the control ratings predict adjustment (Jensen et al. 1991a). Although this is consistent with the hypothesis that the other subscales of the CSQ do not assess coping responses important to adjustment, it is possible that the use of composite scores has obscured potentially significant relationships between individual CSQ coping scores and adjustment. Evidence supporting such associations comes from
’ This factor is usually labeled ‘Pain Control and Rational Thinking’ when the Catastrophizing subscale loads negatively and the control ratings load positively on it. The opposite pattern of loadings is often labeled ‘Helplessness’.
several studies that examined individual CSQ subscales. In one such study, Keefe and Williams (1990) found 3 subscales (Coping Self-Statements, Catastrophizing, and Increasing Activity Level), as well as the 2 control ratings, to be associated with psychological functioning in a group of chronic pain patients. Sullivan and D’Eon (1990) controlled for all other CSQ scales and ratings (by entering them simultaneously in a regression equation), as well as demographic and pain-related variables, and found that only the Catastrophizing subscale predicted depression in a group of chronic low back and neck pain patients. Finally, Jensen and Karoly (1991) found that 3 CSQ subscales (Ignoring Pain, Coping Self-Statements, and Increasing Activity) were associated positively with psychological functioning. Three subscales (Ignoring Pain, Diverting Attention, and Coping Self-Statements) were associated positively with activity level, but only for patients reporting relatively low levels of pain. Although this research suggests that the use of individual coping scales may shed more light on the coping-adjustment relationship than the use of composite measures, no study has compared the predictive ability of composite scores versus individual scores in the same sample of chronic pain patients. The study by Jensen and Karoly (1991) also points to the need to examine moderating factors in the relationship between coping strategies and adjustment to chronic pain. Potentially important moderating variables include pain intensity (Affleck et al. 1987; Jensen and Karoly 1991) and duration of pain (Jensen and Karoly 1992). There are several reasons to examine patient-reported pain intensity as a moderating variable. First, it is possible that patients’ perceptions of pain intensity may act as a ‘3rd variable’ that can influence both coping efforts (patients with a higher level of perceived pain may make more efforts to cope) and functioning (patients with a higher level of perceived pain may function less well than those with lower levels). Second, our clinical experience suggests that patients reporting relatively low levels of pain intensity are more likely to report that certain coping strategies, such as relaxation and ignoring of pain, are beneficial. Finally, previous research supports the potential moderating influence of pain intensity on the relationship between the use of specific coping strategies and functioning (Jensen and Karoly 1991). Pain. duration may also influence the relationship between coping and adjustment. Theoreticians have argued that individuals tend to use coping strategies when they perceive themselves to be under the greatest threat (cf., Wills 1981). We would anticipate that chronic pain may be perceived as less threatening, on average, after an individual has experienced it for a number of years and develops strategies for coping.
215
Thus, it is likely that coping strategies are used more often, and possibly more effectively, earlier on in the development of chronic pain. Empirical support of this hypothesis comes from research that indicates that the use of cognitive coping strategies are more closely associated with positive psychological functioning among individuals who have experienced chronic pain for a relatively short duration (Jensen and Karoly 1992). The primary purpose of this study was to compare the utility of composite scores versus individual coping scale scores in the prediction of adjustment. The study also attempted to replicate the interactions found previously (Jensen and Karoly 1991) between some of the CSQ-assessed coping strategies and pain intensity in the prediction of physical functioning, and to explore the potential moderating effects of pain duration on the coping-adjustment relationship.
Method Subjects The sample was obtained from patients who were admitted to an Inpatient Multidisciplinary Pain Program over a 22-month period (November 1988 to August 1990) and who were eligible to participate in a larger study examining predictors of successful treatment (Jensen et al. 1991bl. Subjects were eligible to participate if they were between the ages of 18 and 65 years (one of the outcome variables was return to work, and this age group was considered to be the most likely to have this as a treatment goal), could read and write English, and did not have evidence of dementia or brain injury. Of the 190 patients who were admitted for treatment, 170 were eligible for the study, and 141 of these agreed to participate. The average age of the study participants was 41 years, and the average duration of their pain was 5.4 years (range: 3 months-40 years). Fifty-six percent of the subjects were women. Seventy-one percent were married or living with a significant other. The rest reported that they were divorced (13%1, had never been married (7%), were separated from their spouse (8%), or were widowed (1%). Sixty-seven percent reported that they were not working due to pain. The others reported that they were working (16%), homemakers (60/o),not working for reasons other than pain (6%1, retired (4%1, or going to school (1%). The majority of the subjects were Caucasian (92%). The rest reported their race as Hispanic (3%1, Native American (2%), Asian cl%), African-American (1%) or ‘other’ (1%). Most of the subjects (76%) reported that they had at least a high school education or general equivalency diploma. The most frequent primary site of pain was the low back (43%). Other primary sites included leg (14%), head (14%), neck (lo%), shoulder/arm (lo%), abdomen (5%), upper back (lo/o), pelvis (I%), anal/genital region (lo/o), and multiple primary sites (1%). The 141 subjects who agreed to participate were compared with the 29 who declined participation through a series of t tests (for age and duration of pain problem) and chi-square analyses (for educational level, race, pain site, marital status, and employment status). No significant differences emerged between the 2 groups of patients.
Measures Pain intensify. Pain intensity was assessed using a lOl-point Numerical Rating Scale (NRS-1011. Subjects were asked to indicate the average intensity of their pain during the past 2 weeks from 0 (no
pain) to 100 (pain as bad as it could be). The NRS-101 has been demonstrated to be a valid measure of pain intensity through its strong association with a linear combination of several pain intensity measures (Jensen et al. 1986, 1989). Coping Strategies Questionnaire (CSQ). The CSQ (Rosenstiel and Keefe 1983) was designed to assess 6 cognitive coping responses to pain (diverting attention, coping self-statements, praying or hoping, reinterpreting pain sensations, catastrophizing, and ignoring pain) and 1 behavioral response (increased behavioral activities). The CSQ also contains 2 items relating to patients’ perceived ability to control and decrease pain. Sickness Impact Profile (SIP). The SIP (Bergner et al. 1981) is a 136-item self-report checklist that assesses the impact of illness on 12 categories of daily functioning. In addition to an overall score, the SIP yields composite physical and psychosocial dysfunction scores. It has demonstrated good to excellent reliability and validity as a measure of dysfunction in a number of samples of chronic pain patients (Follick et al. 1985; Roman0 et al. 1988). Beck Depression Inventory (Bol). The BDI (Beck et al. 1979) is a 21-item self-report measure that requires subjects to report on the incidence of various symptoms of depression. It has demonstrated excellent reliability and validity (Beck et al. 19881, as well as ability to discriminate depressed from non-depressed pain patients (Turner and Roman0 1984).
Procedure Patients who were admitted to the Inpatient Multidisciplinary Chronic Pain Treatment Program at the University of Washington Medical Center were invited to participate in a program evaluation (Jensen et al. 1991b). Those who agreed to participate were asked to complete the NRS-101 and the CSQ within 2 days after admission. The SIP and the BDI are administered to all patients admitted to the Inpatient Pain Management Program as part of their admission assessment. Completed SIPS and BDIs were available for 128 and 117 of the subjects in this study, respectively.
Results Overview of data analyses
The 7 scales and 2 control ratings from the CSQ were subjected to a principal factors analysis using an oblique rotation. Principal factors analysis (PFA) was chosen over other factor analytic procedures because PFA provides a solution uncontaminated by the error variance of the measures. This procedure is appropriate when the goal of the analysis is to understand the hypothetical dimensions embedded in data (Tabachnick and Fidel1 1983). An oblique rotation was selected over orthogonal procedures because it was expected that the resulting coping factors would be related. Correlational analyses were then performed to examine the degree of overlap among the individual CSQ scales. Close associations between the individual CSQ scales would suggest that they do not assess distinct coping strategies and would argue more strongly for combining them into composite measures for statistical analyses (Tabachnick and Fidel1 1983). Following the correlational analyses, a series of multiple regression analyses were performed to determine the extent to which the CSQ factor scores and the individual CSQ
27h
scales and ratings make unique contributions to the prediction of the SIP Physical Dimension, SIP Psychosocial Dimension, and BDI scores. Factor analysis
Two factors emerged from the factor analysis of the CSQ scores, explaining 55% of the variance. The lst, 2nd, and 3rd eigenvalues that emerged were 3.15, 1.84, and 0.90, respectively. The 1st factor was made up of the majority of the CSQ coping scales (Ignore Pain: loading = 0.74; Divert Attention: 0.72; Coping SelfStatements: 0.71; Increase Activities: 0.70; and Reinterpret Pain Sensations: 0.54). This factor is very similar to the ‘Coping Attempts’ factor identified by Keefe et al. (1987a) and Parker et al. (1989) in their 2-factor solutions of the CSQ scales. The 2nd factor was similar to the ‘Helplessness’ factor identified by a number of researchers (RosenstieI and Keefe 1983; Turner and Clancy 1986; Keefe et al. 1990~1, and consisted of the control ratings (Control over pain: loading = -0.63; Ability to decrease pain: - 0.53); The Catastrophizing scale (0.62) and Praying and Hoping (0.39). The 2 factors demonstrated a weak relationship to each other (Y = -0.10). Correlational analyses
In order to determine the degree of overlap between the CSQ subscales and to examine the first-order relationships between the CSQ scales and the adjustment measures, correlation analyses were performed. Of the 36 correlations computed between pairs of individual CSQ scales, only 4 indicated a large degree of overlap (i.e., r = 0.50 or more>. These included the correlations between Ignore Pain and Reinterpreting Pain scales (r = 0.541, the Ignore Pain and Coping Self-Statement scales (r = 0.661, the Increase Activities and Coping Self-Statement scales (r = 0.531, and the Increase Activities and Divert Attention scales (r = 0.61). Qverail, however, the results indicated little overlap between the CSQ scales. The median correlation coefficient between all scales was 0.22, indicating that each scale accounted for less than 5% of the variance in the other scaIes on average. The correlations between the CSQ scores (including both the individual scaies and the composite factor scores) and measures of adjustment are presented in Table I. As can be seen, the CSQ Helplessness composite factor demonstrated a moderate relationship to both the SIP Psychosocial Dysfunction and the BDI scores (rs = 0.31 and 0.39, both Ps < 0.001, 2-tailed tests), but the Coping Attempts factor was not related significantly to any adjustment measure. Only 1 individual CSQ scale score was associated significantly with the SIP Physical Dysfunction score. The Praying and Hoping scale demonstrated a weak positive relationship to physical dysfunction (r = 0.18, P < 0.05, 2-tailed
TABLE
I
CORRELATIGN COEFFICIENTS BETWEEN THE ADJUSTMENT MEASURES AND THE CSQ FACTOR SCORES, SCALES AND RATINGS CSQ = Coping Strategies Questionnaire; file; BDI = Beck Depression Inventory. CSQ measure
FdCtOr
SIP Physical
SIP = Sickness
SIP Psychosocial
Impact
Pro-
BDI
scores
Coping Attempts
0.09
0.08
Helplessness
0.07
0.31 ***
(1.10 0.14 0.1n 0.03 0. IX * 0.14 - (1.04
0.09 0.25 * * 0.40 * * * 0.00 0.14 0.04 - 0.04
- 0.08 0.04 0.53 *** -0.12 0.10 - 0.03 -0.15
-0.19 * - 0.09
-0.26 -0.16
- 0.08 0.39 * * *
Scale scores
Divert Attention Reinterpret Pain Catastrophizing Ignore Pain Pray and Hope Coping Self-Statements Increase Activities Ratings Ability to Control Pain Ability to Decrease Pain -
0.01 0.03
**
* P < O.05; ** P < 0.01; * ** P < 0,001.
test). Reinterpreting Pain Sensations and Catastrophizing were both related positively to the SIP Psychosocial Dysfunction scale (rs = 0.25 and 0.40, Ps < 0.01 and 0.001, respectively, 2-tailed tests), and sense of control over pain was associated negatively with SIP Psychosocial Dysfunction (r = -0.19, P < 0.05, 2-tailed test). BDI scores correlated with Catastrophizing (r = 0.53, P < 0.001, 2-tailed test) and the Pain Control Rating (r = -0.26, P < 0.01, Z-tailed test). Six of the CSQ individual measures demonstrated no significant relationship to the adjustment measures. Multiple regression analyses
A series of 6 regression analyses were performed to determine the relationship between the CSQ scales and the 3 adjustment measures (SIP Physical, SIP Psychosocial, and BDI) while controlling for demographic variables (age, gender), pain-related variables (duration of pain, pain intensity, pain site), and each CSQ measure. Site of pain was defined as low back versus other because the low back pain group was the largest subgroup defined by single pain site (43%). The major predictors (coping measures) were entered in the 3rd step as a block. Interactions of the predictors with the pain-related (moderator) variables were entered in the 4th step in a stepwise fashion (that is, only those that were significant were entered into the equations) using the procedure outlined by Cohen and Cohen (1983) to examine whether pain intensity or duration of the pain problem moderate the relationship between coping and adjustment. Three analyses were conducted to predict the adjustment measures using the CSQ
277
TABLE II RESULTS OF THE MULTIPLE REGRESSION ANALYSES PREDICTING ADJUSTMENT FROM CSQ FACTOR SCORES SIP = Sickness Impact Profile. Step and variable
Total
Change
R2
R2
Beta to enter
F
Criterion: SIP Psychosocial Dysfunction
1 Demographics Age Gender 2 Pain-related variables Pain intensity Pain site Pain duration 3 CSQ factor scores Coping Attempts Helplessness
0.02
0.02
1.37 0.03 -0.14
0.06
0.04
1.86 - 0.01 - 0.02 -0.21 *
0.20
0.13
9.96 * * * 0.19 * 0.38 * * *
Criterion: Beck Depression Inventory
1 Demographics Age Gender 2 Pain-related variables Pain intensity Pain site Pain duration 3 CSQ factor scores Coping Attempts Helplessness
0.01
0.01
0.47 0.07 0.06
0.06
0.06
2.21
0.10 0.01 -0.22 0.22
0.15
*
10.50 *** 0.00 0.40 * * *
* P < 0.05; * * P < 0.01; * * * P < 0.001.
ing relatively low levels of pain (r = 0.171, but was related moderately to physical dysfunction among those reporting medium (r = 0.41, P < 0.01, 2-tailed test) and high levels of pain intensity (r = 0.51, P < 0.001, 2tailed test). Both Reinterpreting Pain Sensations and Catastrophizing made independent contributions to the prediction of SIP Psychosocial Dysfunction when controlling for demographic variables and pain-related variables. In addition, a significant Catastrophizing x Pain Duration interaction emerged in the analysis predicting SIP Psychosocial Dysfunction. To examine this interaction, the subjects were divided into 3 equal groups based on pain duration. Correlations between Catastrophizing and SIP Psychosocial Dysfunction for subjects presenting with pain of relatively short (3 months-2.3 years), medium (2.3-5.2 years), and long (5.3-38.8 years) duration indicated strong relationships among patients with short and medium pain duration (rs = 0.50 and 0.51, Ps < 0.01 and 0.001, respectively, 2-tailed tests), and a non-significant relationship between Catastrophizing and Psychosocial Dysfunction among patients with a long history of pain. The only individual CSQ measure that predicted depression (as measured by the BDI) was the Catastrophizing scale. No interactions of the individual CSQ scales and pain intensity or pain duration were significant in the prediction of depression.
Discussion
factor scores (shown in Table II>, and 3 using the CSQ individual scores (shown in Table III). CSQ composite scores as predictors of adjustment. Both Helplessness and Coping Attempts demonstrated positive relationships to the SIP Psychosocial Dysfunction score. Only the Helplessness factor was associated with the BDI. Neither CSQ factor score was related to the SIP Physical Dysfunction score, and neither interacted with pain intensity or pain duration in the prediction of adjustment. CSQ individual scores as predictors of adjustment. Although no individual CSQ scale demonstrated a significant direct relationship to the SIP Physical Dysfunction score when demographic and pain-related measures were controlled, a significant Coping SelfStatements x Pain Intensity interaction did emerge. In order to examine this interaction more closely, subjects were divided into 3 equal groups based on their pain intensity ratings. Separate correlations were then computed between Coping Self-Statements and SIP Physical Dysfunction for those reporting low (lo-45 on a lOl-point scale), medium (50-651, and high (70-100) levels of pain intensity. The results indicated that the endorsement of Coping Self-Statements was unrelated to SIP Physical Dysfunction for those subjects report-
The primary purpose of this study was to compare the utility of composite versus individual coping measures in the prediction of adjustment among chronic pain patients. The results underscore several important differences between the 2 scoring methods. First, the CSQ factor scores were not superior to individual scale scores in predicting adjustment in this study. That is, the ability to predict outcome was not improved with the use of composite measures. Second, the use of individual scores appears to provide a better understanding of the specific coping strategies that best predict adjustment. For example, even though the Helplessness factor was associated with both measures of psychological functioning, only in the analyses using the individual CSQ scores was it apparent that this relationship was primarily due to Catastrophizing, and not to the control appraisals. Similarly, although the Coping Attempts factor predicted Psychosocial Dysfunction, individual scale analysis revealed that this relationship was mostly due to Reinterpreting Pain Sensations. The present analyses suggest that, of the individual CSQ measures examined, Catastrophizing and Reinterpreting Pain Sensations appear to be the responses that were associated directly with adjust-
278 TABLE
III
TABLE
RESULTS OF PREDICTING SCORES SIP = Sickness
THE MULTIPLE ADJUSTMENT
Impact
REGRESSION FROM CSQ
ANALYSES INDIVIDUAL
Profile.
Step and variable
Total
Change
R2
R=
F
0.02
1.20
Criterion: SIP Physical Dysfunction 1 Demographics 0.02 Age Gender 2 Pain-related variables Pain intensity Pain site Pain duration 3 CSQ individual scores Coping Self-Statements Pray and Hope Reinterpret Pain Sensations Catastrophize Divert Attention Increase Activities Ignore Pain Ability to Control Pain Ability to Decrease Pain 4 Interaction Coping Self-Statements X Pain Intensity
Total
Change
R2
n
Increase Activities Ignore Pain Ability to Control Pain Ability to Decrease Pain
Beta to enter
Beta to enter -0.22 0.02 - 0.03 - 0.06
* P < 0.05; * * P < 0.01; * * * P < 0.001.
0.12
0.10
4.76 * * 0.08 -0.24 ** -0.18 *
0.08
0.20
1.24 0.20 0.12 0.15 0.10 0.08 -0.17 -0.16 0.05 0.02
0.24
0.04
5.60 *
0.02
1.37
-0.81
*
0.03 -0.14 0.06
0.04
1.86 - 0.01 - 0.02 -0.21 *
0.29
0.21
3.91 * * * 0.01 0.00 0.23 * 0.38 *** 0.10 - 0.06 - 0.02 - 0.07 0.01
0.31
0.03
4.32 *
Criterion: Beck Depression Imentory 1 Demographics 0.01
0.01
0.47
Age Gender 2 Pain-related variables Pain intensity Pain site Pain duration 3 CSQ individual scores Coping Self-Statements Pray and Hope Reinterpret Pain Sensations Catastrophize Divert Attention
Step and variable
0.14 - 0.01
Criterion: SIP Psychosocial Dysfunction 1 Demographics 0.02 Age Gender 2 Pain-related variables Pain intensity Pain site Pain duration 3 CSQ individual scores Coping Self-Statements Pray and Hope Reinterpret Pain Sensations Catastrophize Divert Attention Increase Activities Ignore Pain Ability to Control Pain Ability to Decrease Pain 4 Interaction Catastrophize x Pain Duration
III (continued)
-0.32
*
0.07 0.06 0.06
0.06
2.21 0.10 0.01 -0.22 *
0.38
0.31
5.71 * ** 0.15 -0.08 0.03 0.54 * * * 0.02
ment. These results need to be cross-validated and then tested using experimental designs to determine whether causal relationships exist between these responses and dimensions of adjustment. Further evidence supporting the usefulness of individual scale scores comes from the significant interactions that emerged in the prediction of adjustment. Although no interactions were found using the composite measures, 2 interactions emerged when the individual scores were used. This finding suggests that the use of individual scale scores may lead to a better understanding of the more complex relationships that can exist between coping and adjustment. One of the interactions found was inconsistent with results of previous research. In the present study, the use of coping self-statements was related positively to physical dysfunction among those who reported higher levels of pain, whereas in previous research coping self-statements were related negatively to physical dysfunction, but only among subjects reporting relatively low levels of pain intensity (Jensen and Karoly 1991). There are several possible explanations for this discrepant finding. First, there may be differences specific to the pain populations studied. Patients differ across treatment sites (Holzman et al. 1985), and it is possible that unique characteristics of each population may have influenced the findings. Second, the criterion measures differed in the two studies. The use of coping selfstatements may have a different relationship to activity level as assessed by the activity scales of the Multidimensional Pain Inventory (the criterion used in Jensen and Karoly 1991) than to physical dysfunction as assessed by the SIP (the criterion used in the present study), which encompasses other dimensions of functioning such as ambulation, mobility, and body care. Additional studies are needed to replicate and explore further these findings. The interaction found in the present study between the use of catastrophizing and pain duration in the prediction of psychosocial dysfunction is similar to findings of previous research (Jensen and Karoly 1992). In both studies, cognitive responses to pain (catastrophizing in the present study and not making positive comparisons of oneself and one’s situation to other people and situations in Jensen and Karoly’s
279
study (1992)) were more strongly associated with poor psychological functioning among those with pain of a shorter duration. It is possible that cognitive responses have their greatest impact upon psychological adjustment in the first few years following the onset of pain. One limitation of this study is its reliance on self-report measures of coping and adjustment. A replication of the present findings with other measures (including observational measures) of coping and functioning is indicated. Also, given that the study is a cross-sectional correlational design, it is not possible to make causal statements regarding the association between coping strategies and adjustment based on the findings. A third limitation is that the results have unknown generalizability. Because the sample was obtained from a group of patients admitted to an Inpatient Pain Program, the findings may not generalize to other populations of individuals experiencing pain. Also, the pain coping measure used (CSQ) is primarily a measure of cognitive, not behavioral, pain coping strategies. The results might have been different if additional pain strategies had been assessed. Despite these limitations, this study involved the first comparison of composite coping scores to individual coping strategy measures in the prediction of adjustment to chronic pain. Although the results indicate that the use of individual scale scores may be more informative, the use of composites still has merit, and should not be abandoned (see Jensen et al. 1991a). However, when measuring dimensions that may be only weakly to moderately related to one another (as appears to be the case among the subscales of the CSQ), the exclusive use of composites potentially can impede the understanding of how coping relates to adjustment.
Acknowledgements
This research was supported by a National Research Service Award (F32 NS08545) to M.P.J. and a Graduate School Research Fund grant from the University of Washington to J.M.R.
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