ORIGINAL ARTICLE
Hospital-based Acute Care After Outpatient Colonoscopy Implications for Quality Measurement in the Ambulatory Setting Justin P. Fox, MD, MHS,* Deepika D’Cunha Burkardt, DO,* Isuru Ranasinghe, MBChB, MMed, PhD,w and Cary P. Gross, MDz
Introduction: Ambulatory surgery centers now report immediate hospital transfer rates as a measure of quality. For patients undergoing colonoscopy, this measure may fail to capture adverse events, which occur after discharge yet still require a hospital-based acute care encounter. Objective: We conducted this study to estimate rates of immediate hospital transfer and hospital-based acute care following outpatient colonoscopy performed in ambulatory surgery centers. Research Design and Subjects: Using state ambulatory surgery databases from the 2009–2010 Healthcare Cost and Utilization Project, we identified adult patients who underwent colonoscopy. Immediate hospital transfer and overall acute health care utilization in the 14 days following colonoscopy was determined from corresponding inpatient, ambulatory surgery, and emergency department databases. To compare rates across centers while accounting for differences in patient populations, we calculated risk-standardized rates using hierarchical generalized linear modeling. Results: The final sample included 1,137,381 colonoscopy discharges from 1019 centers. At the ambulatory surgery center level, the median risk-standardized hospital transfer rate was 0.0% (interquartile range = 0.0%), whereas the hospital-based acute care rate was 2.1% (interquartile range = 0.6%), with few centers (N = 36) having no observed encounters. No correlation was noted between From the *Department of Surgery, Boonshoft School of Medicine, Wright State University, Dayton, OH; wCenter for Outcomes Research and Evaluation; and zRobert Wood Johnson Foundation Clinical Scholars Program, Section of General Internal Medicine, and Cancer Outcomes Policy and Effectiveness Research (COPPER) Center, Yale University School of Medicine, New Haven, CT. The views expressed in this article are those of the authors and do not reflect the official policy of the United States Air Force, Department of Defense, Centers for Medicare & Medicaid Services, or the US Government. I.R. works under contract with the Centers for Medicare & Medicaid Services to develop and maintain performance measures, and is supported by an Early Career Fellowship co-funded by the National Health and Medical Research Council of Australia and the National Heart Foundation of Australia. The remaining authors declare no conflict of interest. Reprints: Justin P. Fox, MD, MHS, Miami Valley Hospital, One Wyoming Street, Suite 7000 WCHE, Dayton, OH 45409. E-mail: justin_p_fox@ yahoo.com. Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Website, www.lww-medical care.com. Copyright r 2014 by Lippincott Williams & Wilkins ISSN: 0025-7079/14/5209-0801
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the risk-standardized hospital transfer and hospital-based acute care rates (volume weighted correlation coefficient = 0.04, P = 0.16). Conclusions: Patients more frequently experience hospital-based acute care encounters after colonoscopy than the need for immediate hospital transfer. Broadening existing quality measures to include hospital-based acute care in the postdischarge period may provide a more complete measure of quality. Key Words: hospital based acute care, ambulatory surgery center, quality measurement (Med Care 2014;52: 801–808)
Q
uality improvement initiatives, including value-based purchasing programs, have been evaluating health care outcomes and assessing relative performance among hospitals and providers for several years. Most notably, a hospital’s mortality and readmission rates for selected conditions are publically reported and financial reimbursement adjusted based on performance. As the delivery of health care shifts from the inpatient to the outpatient setting,1 quality measurement efforts have followed. Beginning in 2012, the Centers for Medicare and Medicaid Services (CMS) expanded quality measurement efforts to ambulatory surgery centers (ASC).2,3 These efforts require ASC to self-report 5 quality measures, including the rate at which patients are immediately transferred to a hospital rather than discharged home. This measure is meant to serve as a surrogate marker for serious adverse events. For colonoscopy, which accounts for nearly 1 in every 5 discharges from ASC,4 the immediate hospital transfer rates may not be an accurate barometer for the quality of care provided. Although colonoscopy can often be accomplished safely, the procedure is associated with a measurable rate of adverse events both during the procedure and after discharge.5,6 Prior studies have found patients may re-present to health care after being discharged home for diagnoses ranging from pain and nausea to gastrointestinal bleeding and colonic perforation.7–11 Although some symptoms may be expected following colonoscopy, acute-onset symptoms that prompt presentation to medical attention, whether as return ASC encounters, emergency department visits, or hospital admissions, can adversely affect a patient’s quality of life and result in additional health care expenditures.10 As medical and surgical procedures are migrating to ambulatory setting, including ASC and hospital-based outwww.lww-medicalcare.com |
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patient departments, a critical assessment of accompanying quality metrics is needed to determine their ability to adequately inform patient and payer decision making. Currently, little is known regarding the frequency or variation in hospital transfer rates when applying contemporary risk standardization methods or if focusing on this time period may miss important adverse events after home discharge. If the hospital transfer rate is exceptionally uncommon, misses a substantial number of events, or varies little across ambulatory centers, its ability to provide meaningful information for quality assessment is limited. To this end, we analyzed data from patients undergoing colonoscopy in ASC and hospital-based outpatient departments across 4 states to determine variation in risk standardized, immediate hospital transfer and hospital-based acute care rates within 14 days of discharge. We hypothesized that immediate hospital transfer would be uncommon and underestimate the frequency of adverse events following colonoscopy.
METHODS We conducted a retrospective cohort study using administrative data from the 2009–2010 California (CA), Florida (FL), Nebraska (NE), and New York (NY) state ambulatory surgery, inpatient, and emergency department databases. These data are compiled at the state level from administrative, clinical, and billing information, standardized across states, and then made available through the Healthcare Cost and Utilization Project (HCUP).12 The ASC database is either a census of discharges from free-standing ASC and hospital-based outpatient departments (CA, FL, and NY) or free-standing ASC alone (NE). The inpatient databases are a census of discharges from all acute care, non-federal, community hospitals, whereas the emergency department databases are a census of emergency department encounters which do not result in hospital admission. However, if a patient presents to the hospital emergency department and is subsequently admitted to the hospital, the patient would be captured by the inpatient database. Each discharge abstract contains at least 9 Current Procedural Terminology (CPT) or International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes, 15 diagnostic ICD-9-CM codes, and information about patient demographics, anticipated payer, and discharge disposition. These states were selected for analysis because of their geographic diversity, large populations, and availability of the encrypted identifiers which allow patients to be followed over time and across health care settings. In 2010, the population of these states accounted for 25% of the total US population.13
Patient Selection From the ASC databases, we identified discharges for state residents at least 18 years of age, had an encrypted patient identifier, and underwent colonoscopy as their primary procedure (CPT-4 codes 45378, 45380, 45381, 45383, 45384, 45385, 45391, and HCPCS codes G0105, G0121) between July 2009 and September 2010. From this population (N = 1,379,549), we sequentially excluded discharges with a concurrent procedure code for upper endoscopy
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(N = 182,408) and where the discharge disposition was recorded as missing, death, or left against medical advice (N = 1179). To create a more homogenous sample of patients and for consistency with prior reports,7 we excluded patients with a diagnosis of inflammatory bowel disease (N = 25,573) or recent diagnoses of diverticulitis (N = 10,517) or colorectal cancer (N = 7203). Finally, we excluded ASC reporting 1 of these outcomes within 14 days, we also calculated event rates per 1000 discharges with 95% confidence intervals (CI). Finally, we evaluated the variation in risk-standardized outcomes across ASC by creating 2-level (patient and ASC) hierarchical logistic regression models for each outcome, using similar methods to those used by the CMS.19 The previously described covariates were entered into 3 separate logistic regression models, 1 for each outcome. Using a backward selection process with a retention P-value of 0.05, we created the most parsimonious models. All authors then reviewed these variables to ensure they were clinically appropriate. The final variables for risk adjustment included: age, sex, anticipated primary payer, 26 medical comorbidities, discharge diagnosis, and whether a biopsy or polypectomy was performed. Models also included ASC-level random intercepts to account for clustering of patients within ASC and permit separation of the within and between ASC variation in outcomes after accounting for patient characteristics. The predicted-to-estimated ratio obtained from these models was then multiplied by the mean unadjusted outcome rate among all ASC included in the study to yield the risk-standardized rates. Finally, we conducted these same analyses among 3 subgroups: the non-Medicare population, discharges from free-standing ASC, and the “screening” colonoscopy cohort which was identified using diagnostic coding. All analyses were conducted using SAS version 9.3 (SAS Institute, Cary, NC). Because this study used publicly available data that does not include patient identifiers, it was considered exempt from review by the Wright State University Institutional Review Board and Yale University Human Investigations Committee.
RESULTS The final sample included 1,137,381 discharges from 1019 ASC in 4 states. Over half of the discharges were for women (52.5%) without significant medical comorbidity (77.2%) and with private insurance (56.0%). A biopsy or polypectomy was performed during more than half (54.8%) of the procedures. The most common primary diagnosis associated with the colonoscopy discharge was “screening” (31.9%) or “benign neoplasms” (28.7%; Table 1).”
Description of Hospital Transfer and Hospitalbased Acute Care Within 14 Days Relatively few discharges were associated with an immediate hospital transfer (N = 344; 0.03%). When a hospital transfer did occur, the most commonly associated diagnoses were for accidental operative laceration, abdominal pain, and cardiopulmonary complications. Conversely, 24,513 discharges (2.2%) were associated with a hospitalr
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No. discharges Age, median (SD) (y) Sex Male Female Missing Race and ethnicity White Black Hispanic Other Missing Primary payer Medicare Medicaid Private Other State of residence California Florida Nebraska New York Free-standing ambulatory surgery center Comorbid medical conditions No conditions 1–2 conditions 3–4 conditions Z5 conditions Diagnosis associated with colonoscopy Screening Benign neoplasms Diverticulosis Other gastrointestinal disorders Gastrointestinal hemorrhage All other diagnoses Colonoscopy with biopsy
1,137,381 (100.0) 60.0 (12.3) 527,949 (46.4) 596,624 (52.5) 12,808 (1.1) 733,160 89,795 128,915 98,651 86,860
(64.5) (7.9) (11.3) (8.7) (7.6)
374,888 61,595 637,350 63,548
(33.0) (5.4) (56.0) (5.6)
327,963 512,859 13,072 283,487 546,003
(28.8) (45.1) (1.2) (24.9) (48.0)
878,326 217,253 32,653 9,149
(77.2) (19.1) (2.9) (0.8)
362,842 326,935 64,362 107,495 76,746 199,001 622,847
(31.9) (28.7) (5.7) (9.5) (6.8) (17.5) (54.8)
based acute care encounter within 14 days of discharge for a rate of 24.2 encounters (95% CI, 23.9–24.5)/1000 discharges (Fig. 1). Hospital admissions [0.9%; 9.7 (9.5–9.8)/1000] and emergency department visits [1.3%; 12.6 (12.4–12.8)/1000] occurred with similar frequency, but for different associated diagnoses. Hemorrhage, diverticulitis, benign neoplasms, accidental operative laceration, and coronary artery disease were common diagnoses associated with hospital admission. For emergency department visits, symptoms such as abdominal or chest pain and urinary tract infection were more common. Finally, a subsequent ASC encounter due to bleeding within 14 days of colonoscopy occurred with a frequency similar to hospital transfer (0.03%; Table 2).
Factors Associated With Hospital-based Acute Care From the final model used for risk adjustment, several variables were associated with more frequent hospital-based acute care within 14 days of discharge. Regarding the type of colonoscopy, those who had an associated diagnosis other than “screening” or had a concurrent biopsy performed [adjusted odds ratio (AOR) = 1.32 (95% CI, 1.29–1.36)] more frequently had a hospital-based acute care encounter www.lww-medicalcare.com |
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FIGURE 1. Frequency of hospital-based acute care encounters (y-axis) in the overall population according to the number of days before or after colonoscopy (x-axis).
after discharge. Differences were also noted across payers. With Medicare as the reference, discharges where Medicaid [AOR = 1.38 (95% CI, 1.32–1.45)] was the anticipated primary payer was associated with more frequent hospital-based acute care encounters, whereas Private [AOR = 0.59 (0.57–0.61)] forms of insurance were associated with less frequent encounters. Patient comorbidity was also related to these postdischarge events, including several cardiopulmonary
conditions and a history of metastatic cancer [AOR = 2.18 (1.72–2.75)]. Notably, discharges where the patient had known fluid or electrolyte disorders [AOR = 1.90 (1.76–2.06)] were associated with more frequent hospital-based acute care encounters (Table 3). Similar findings were noted in the model for immediate hospital transfer (see Supplemental Digital Content 3, http://links.lww.com/MLR/A752 for full results of the immediate hospital transfer model).
TABLE 2. Hospital-based Acute Care and Adverse Events Within 14 Days of Outpatient Colonoscopy Rate/1000 discharges (95% CI)z N* (%w) Hospital-based acute care Immediate hospital transfer
24,513 (2.2)
Estimate LCI UCI 24.2
23.9
Most common
Second
Third
Hemorrhage complicating a procedure 0.34 Accidental operative laceration 0.33 Rectal and anal hemorrhage
Abdominal pain
Diverticulitis
24.5
344 (0.0)
0.30
0.27
Ambulatory 327 (0.0) surgery center encounter Hospital admission 10,533 (0.9)
0.29
0.26
9.7
9.5
9.8
12.6
12.4
12.8
Emergency 14,407 (1.3) department visit
Associated diagnosesy
Hemorrhage complicating a procedure Abdominal pain
Fourth Chest pain
Atrial Abdominal pain fibrillation
Fifth Gastrointestinal hemorrhage
Respiratory Surgical complications complications: cardiac Gastrointestinal Surgical hemorrhage complications: gastrointestinal tract Accidental Coronary artery operative disease laceration Chest pain Gastrointestinal hemorrhage
Melena
Hemorrhage complicating a procedure Diverticulitis Benign neoplasm of the colon
Urinary tract Rectal and anal infection hemorrhage
*Number of patients in the total sample experiencing at least 1 event. w Percentage of patients in the total sample experiencing at least 1 event. z Number of events per 1000 discharges experienced by the total population. y On the basis of first listed ICD-9-CM diagnostic code.
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TABLE 3. Results From the Hierarchical Logistic Regression Model for Hospital-based Acute Care Within 14 Days of Colonoscopy Diagnosis associated with colonoscopy Screening Benign neoplasms Diverticulosis Other gastrointestinal disorders Gastrointestinal hemorrhage All other diagnoses Colonoscopy with biopsy Age (y) Sex Male Female Primary payer Medicare Medicaid Private Other Medical comorbidity Congestive heart failure Cardiac arrhythmia Valvular disease Peripheral vascular disorders Hypertension uncomplicated Other neurological disorders Chronic pulmonary disease Diabetes uncomplicated Diabetes complicated Renal failure Liver disease Peptic ulcer disease, excluding bleeding Lymphoma Metastatic cancer Solid tumor without metastasis Rheumatoid arthritis/collagen vascular disease Coagulopathy Obesity Weight loss Fluid and electrolyte disorders Blood loss anemia Deficiency anemia Alcohol abuse Drug abuse Psychoses Depression
N* (%w)
Odds Ratio
Lower 95% CI
Upper 95% CI
362,842 (1.5) 326,935 (2.3) 64,362 (2.5) 107,495 (2.7) 76,746 (2.5) 199,001 (2.7) 622,847 (2.4) —
1.36 1.58 1.60 1.60 1.62 1.32 0.99
Reference 1.31 1.49 1.53 1.52 1.55 1.29 0.99
1.42 1.68 1.68 1.69 1.68 1.36 0.99
527,949 (2.1) 596,624 (2.2)
1.08
Reference 1.05
1.11
374,888 61,595 637,350 63,548
(2.8) (4.5) (1.5) (2.3)
1.38 0.59 0.83
Reference 1.32 0.57 0.78
1.45 0.61 0.88
6757 19,776 6769 5239 169,371 6254 34,781 62,379 3847 7885 6484 1701 978 945 4094 4227 1932 16,936 8863 8947 1698 14,046 3153 1977 1770 16,315
(10.6) (6.8) (5.7) (8.0) (3.6) (8.0) (6.2) (4.6) (10.3) (9.0) (7.0) (9.2) (6.9) (10.8) (6.4) (6.6) (10.7) (5.1) (6.0) (13.0) (8.7) (4.8) (10.3) (14.3) (11.1) (7.1)
1.25 1.56 1.11 1.24 1.32 1.49 1.54 1.30 1.31 1.49 1.30 1.53 1.67 2.18 1.46 1.47 1.21 1.11 1.51 1.90 1.41 1.31 1.47 1.78 1.53 1.51
1.13 1.46 0.99 1.11 1.28 1.35 1.46 1.25 1.16 1.35 1.17 1.28 1.29 1.72 1.27 1.29 1.03 1.02 1.37 1.76 1.17 1.20 1.29 1.54 1.30 1.41
1.38 1.67 1.25 1.39 1.37 1.65 1.62 1.37 1.49 1.64 1.46 1.84 2.18 2.75 1.69 1.67 1.43 1.20 1.66 2.06 1.70 1.42 1.69 2.06 1.81 1.62
C-statistic = 0.66. *Number of patients in the sample within given variable. w Percentage of patients within given variable experiencing the outcome. CI indicates confidence interval.
Variation in Hospital Transfer and Hospitalbased Acute Care Across Centers At the ASC level, the risk-standardized hospital transfer rate was low (median = 0.0%, interquartile range = 0.0%), with minimal variation across centers, and nearly 89.2% of centers had no hospital transfers. Conversely, the risk-standardized hospital-based acute care rate was more common (median = 2.1%, interquartile range = 0.6%), had more variability, and fewer centers (3.5%) had no observed encounters. No correlation was noted between the risk-standardized hospital transfer and hospital-based acute care rates (volume-weighted correlation coefficient = 0.04, P = 0.16). After accounting for differences in patient case-mix across facilities, the composite measure including immediate hospital transfer and hospitalr
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based acute care in the postdischarge period varied >3-fold across ASC (median = 2.2%, 1st percentile = 1.2%, 99th percentile = 3.7%; Fig. 2).
Subgroup Analysis The same analyses described above were conducted among the non-Medicare population (discharges = 762,493, centers = 1018), those treated at free-standing ASC (discharges = 559,075, centers = 365), and among the “screening” colonoscopy cohort (discharges = 362,842, centers = 997). Although the exact transfer and hospital-based acute care rates differed slightly among these subgroups, the overall finding that hospital-based acute care rates were much larger than hospital transfer rates was consistent with the overall www.lww-medicalcare.com |
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FIGURE 2. A, Variation in ambulatory surgery centers’ risk-standardized hospital transfer rate at the time of discharge following colonoscopy. B, Variation in ambulatory surgery centers’ risk-standardized hospital-based acute care rate within 14 days of discharge following colonoscopy.
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sample (see Supplemental Digital Content 4, http://links. lww.com/MLR/A753 for detailed results of the subgroup analyses).
DISCUSSION Outpatient colonoscopy remains a safe procedure; however, monitoring hospital transfer rates as a measure of quality will fail to identify 98% of hospital-based acute care utilization after home discharge. As scrutiny of outpatient quality and outcomes increases, it is essential to assess the validity and potential impact of proposed performance measures. The acute care events that our approach identified represent important patient outcomes, as they were often associated with symptoms or diagnoses likely related to the procedure including bleeding and perforation, and may add to the costs of care. The utility of hospital transfer rates as a quality measure is further limited by the lack of variation in this outcomes noted across centers, thus preventing meaningful stratification of centers into those that are high or low performing. Broadening the current quality measure beyond the immediate discharge disposition may be warranted to more completely capture adverse events related to care and more accurately determine ASC performance. Failing to account for these postdischarge events may misinform health care payers and patients by not accurately identifying centers as high or low performing. The diagnoses associated with the need for immediate hospital transfer are similar to those seen among patients discharged home and returning to the hospital, further supporting their inclusion in a quality measure. Among those transferred to the hospital, cardiorespiratory complications, gastrointestinal perforation, and abdominal pain were common diagnoses. These diagnoses are likely related to the bowel preparation, sedation for the procedure,11 or the procedure itself.6,20 Yet, it is important to note that patients who were discharged home and readmitted within 14 days had similar diagnoses. This raises the possibility that those transferred to the hospital from an ASC represents a cohort of patients for whom a complication of care was identified before discharge. Conversely, patients who were discharged home only to return to the hospital may represent a cohort of patients with missed complications at the time of the procedure. The failure of current quality measures3 that focus on the immediate hospital transfer fail to capture adverse events occurring after a home discharge has important implications for quality measurement efforts, health care providers, and ultimately patients. First, this measure may have unintended consequences whereby health care providers err on the side of home discharge rather than hospital transfer for further evaluation for patients in whom an obvious disposition is not clear. If the patient then develops an adverse event at home prompting a return to the hospital, the encounter would not count toward an adverse event for the ambulatory surgery but has the potential to be detrimental for patients. Second, ASC with liberal home discharge policies, whether appropriate or not, will seem to be better performing than more conservative centers with similar hospital-based acute care rates. r
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Hospital-based Acute Care After Colonoscopy
If performance on the current hospital transfer measure is then tied to financial reimbursement, these ASC with higher hospital transfer rates but lower hospital-based acute care rates could be unfairly penalized. Measuring hospital-based acute care after outpatient colonoscopy may have some advantages over other proposed colonoscopy quality measures, including patient satisfaction scores21 and technical competence as reflected by cecal intubation and colonoscopy completion rates.22 Although patient surveys provide important information about the patient experience, broad implementation would require significant efforts to develop, test, and implement standardized colonoscopy-specific surveys across ASC. Cecal intubation and colonoscopy completion rates are critically important to the effectiveness of colonoscopy; however, these outcomes would likely require self-reporting posing a conflict of interest and sacrificing objectivity. Monitoring the postdischarge period may provide an opportunity to compare outcomes across centers with a low burden to individual ASC while maintaining objectivity. This is not without its own limitations, including attributing all hospital-based acute care visits to the colonoscopy and the potential for capturing visits as part of a planned treatment course (ie, colon resection after a cancer is diagnosed). Further efforts should develop a postdischarge algorithm to maximize capturing events which are likely complications of care while minimizing identification of planned or unrelated health care contacts. The variation in hospital-based acute care encounters across ASC likely represents a modifiable outcome. Health care providers in ASC have previously recognized patient’s needs after discharge23–25 and described practices throughout the patient encounter which may mitigate hospital-based acute care utilization after discharge. These practices begin before the procedure with ensuring the patient has an adequate indication for the colonoscopy and then identifying patients at risk for periprocedural complications.26 In the current study, patients with significant heart disease including arrhythmias, cardiac valvular disease, and heart failure were more likely to return to the hospital.27 This may be reflected in diagnoses of cardiac arrhythmias and chest pain frequently being seen associated with hospital return. Further, patients with fluid and electrolyte disorders, renal failure, and liver disease were also more likely to return to the hospital. This raises the question of how well the bowel preparation is tolerated in these patients.28 During the procedure, it is important to ensure anesthesia is provided safely29,30 and that the patient recovers from these medications before discharge to minimize adverse events.31 Finally, after patients are discharged some centers have provided telephonic follow-up to monitor recovery, provided patients with after-hours contact information, and focused on patient education regarding expected symptoms following colonoscopy.21,32 The current study should be interpreted in the context of several limitations. First, patients who were readmitted to a hospital outside their state of residence could not be accounted for in this study. In addition, if patients lived in “border towns” and underwent colonoscopy in one state, but sought postdischarge care in another, these events could be missed leading www.lww-medicalcare.com |
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to an underestimation of postdischarge hospital-based acute care. To limit the influence of this factor, we restricted our population to state residents. Second, we did not include visits to physician offices in the 7 days following colonoscopy. Therefore, if adverse events were effectively managed in the physician’s office without subsequent emergency department visits or hospital admissions, they would not be included in this study further leading to an underestimation of adverse events. Finally, the dataset utilized is subject to the accuracy of the coding provided. Identifying specific complications from administrative data can be problematic.33 By focusing on the frequency of health care contacts experienced by patients following the procedure, we do not rely on the accuracy of specific ICD-9-CM code selection for identifying patients. In conclusion, hospital transfer at the time of discharge fails to adequately capture adverse events related to outpatient colonoscopy. Broadening the quality measurement period to the 14 days following discharge may provide a more patient-centered outcome while better assessing the quality of care provided and a more meaningful determination of “high” and “low” performing centers. REFERENCES 1. Manchikanti L, Singh V, Hirsch JA. Saga of payment systems of ambulatory surgery centers for interventional techniques: an update. Pain Physician. 2012;15:109–130. 2. Rollins G. Final five: ASCs told to target patient safety. Hosp Health Netw. 2007;81:53–54, 56, 51. 3. Centers for Medicare & Medicaid Services (CMS), HHS. Medicare program; revised payment system policies for services furnished in ambulatory surgical centers (ASCs) beginning in CY 2008. Final rule. Fed Regist. 2007;72:42469–42626. 4. Russo A, Elixhauser A, Steiner C, et al. Utilization Project Statistical B. Hospital-Based Ambulatory Surgery, 2007: Statistical Brief #862006. 5. Day LW, Kwon A, Inadomi JM, et al. Adverse events in older patients undergoing colonoscopy: a systematic review and meta-analysis. Gastrointest Endosc. 2011;74:885–896. 6. Ko CW, Riffle S, Michaels L, et al. Serious complications within 30 days of screening and surveillance colonoscopy are uncommon. Clin Gastroenterol Hepatol. 2010;8:166–173. 7. Warren JL, Klabunde CN, Mariotto AB, et al. Adverse events after outpatient colonoscopy in the Medicare population. Ann Intern Med. 2009;150:849–857, W152. 8. Stock C, Ihle P, Sieg A, et al. Adverse events requiring hospitalization within 30 days after outpatient screening and nonscreening colonoscopies. Gastrointest Endosc. 2013;77:419–429. 9. Rabeneck L, Saskin R, Paszat LF. Onset and clinical course of bleeding and perforation after outpatient colonoscopy: a population-based study. Gastrointest Endosc. 2011;73:520–523. 10. Leffler DA, Kheraj R, Garud S, et al. The incidence and cost of unexpected hospital use after scheduled outpatient endoscopy. Arch Intern Med. 2010;170:1752–1757. 11. Cooper GS, Kou TD, Rex DK. Complications following colonoscopy with anesthesia assistance: a population-based analysis. JAMA Intern Med. 2013;173:551–556. 12. HCUP. Overview of healthcare cost and utilization project, 2012. Available at: http://www.hcup-us.ahrq.gov/overview.jsp. Accessed May 8, 2012.
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13. US Census Bureau. Summary File 1. 2010. Available at: http:// www.census.gov/2010census/. Accessed October 10, 2013. 14. AGA. AGA quality and outcomes measures. Available at: http://www. gastro.org/practice/quality-initiatives/performance-measures/aga-qualityand-outcomes-measures. Accessed August 3, 2013. 15. Rex DK, Petrini JL, Baron TH, et al. Quality indicators for colonoscopy. Am J Gastroenterol. 2006;101:873–885. 16. HCUP. Clinical classifications software (CCS) for ICD-9-CM, 2012. Available at: http://www.hcup-us.ahrq.gov/toolssoftware/ccs/ccs.jsp. Accessed April 16, 2012. 17. Elixhauser A, Steiner C, Harris DR, et al. Comorbidity measures for use with administrative data. Med Care. 1998;36:8–27. 18. Quan H, Sundararajan V, Halfon P, et al. Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data. Med Care. 2005;43:1130–1139. 19. Krumholz HM, Lin Z, Drye EE, et al. An administrative claims measure suitable for profiling hospital performance based on 30-day all-cause readmission rates among patients with acute myocardial infarction. Circ Cardiovasc Qual Outcomes. 2011;4:243–252. 20. Ko CW, Riffle S, Shapiro JA, et al. Incidence of minor complications and time lost from normal activities after screening or surveillance colonoscopy. Gastrointest Endosc. 2007;65:648–656. 21. Sewitch MJ, Dube C, Brien S, et al. Patient-identified quality indicators for colonoscopy services. Can J Gastroenterol. 2013;27: 25–32. 22. Hewett DG, Rex DK. Improving colonoscopy quality through healthcare payment reform. Am J Gastroenterol. 2010;105:1925–1933. 23. Mezei G, Chung F. Return hospital visits and hospital readmissions after ambulatory surgery. Ann Surg. 1999;230:721–727. 24. Twersky R, Fishman D, Homel P. What happens after discharge? Return hospital visits after ambulatory surgery. Anesth Analg. 1997;84: 319–324. 25. Warner MA, Shields SE, Chute CG. Major morbidity and mortality within 1 month of ambulatory surgery and anesthesia. JAMA. 1993;270: 1437–1441. 26. Mehta PP, Kochhar G, Kalra S, et al. Can a validated sleep apnea scoring system predict cardiopulmonary events using propofol sedation for routine EGD or colonoscopy? A prospective cohort study. Gastrointest Endosc. 2014;79:436–444. 27. Rex DK, Bond JH, Winawer S, et al. Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: recommendations of the US Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol. 2002;97: 1296–1308. 28. Enestvedt BK, Tofani C, Laine LA, et al. 4-Liter split-dose polyethylene glycol is superior to other bowel preparations, based on systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2012;10: 1225–1231. 29. Bui AH, Urman RD. Clinical and safety considerations for moderate and deep sedation. J Med Pract Manage. 2013;29:35–41. 30. Metzner J, Domino KB. Risks of anesthesia or sedation outside the operating room: the role of the anesthesia care provider. Curr Opin Anaesthesiol. 2010;23:523–531. 31. Trevisani L, Cifala` V, Gilli G, et al. Post-Anaesthetic Discharge Scoring System to assess patient recovery and discharge after colonoscopy. World J Gastrointest Endosc. 2013;16:502–507. 32. Pennsylvania Patient Safety Reporting System. Unanticipated care after discharge from ambulatory surgical facilities, 2005. Available at: http:// patientsafetyauthority.org/ADVISORIES/AdvisoryLibrary/2005/dec2(4)/ Documents/01b.pdf. Accessed April 11, 2012. 33. Lawson EH, Louie R, Zingmond DS, et al. A comparison of clinical registry versus administrative claims data for reporting of 30-day surgical complications. Ann Surg. 2012;256:973–981.
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Hospital-based Acute Care After Outpatient Colonoscopy Implications for Quality Measurement in the Ambulatory Setting Justin P. Fox, MD, MHS,* Deepika D’Cunha Burkardt, DO,* Isuru Ranasinghe, MBChB, MMed, PhD,w and Cary P. Gross, MDz
Introduction: Ambulatory surgery centers now report immediate hospital transfer rates as a measure of quality. For patients undergoing colonoscopy, this measure may fail to capture adverse events, which occur after discharge yet still require a hospital-based acute care encounter. Objective: We conducted this study to estimate rates of immediate hospital transfer and hospital-based acute care following outpatient colonoscopy performed in ambulatory surgery centers. Research Design and Subjects: Using state ambulatory surgery databases from the 2009–2010 Healthcare Cost and Utilization Project, we identified adult patients who underwent colonoscopy. Immediate hospital transfer and overall acute health care utilization in the 14 days following colonoscopy was determined from corresponding inpatient, ambulatory surgery, and emergency department databases. To compare rates across centers while accounting for differences in patient populations, we calculated risk-standardized rates using hierarchical generalized linear modeling. Results: The final sample included 1,137,381 colonoscopy discharges from 1019 centers. At the ambulatory surgery center level, the median risk-standardized hospital transfer rate was 0.0% (interquartile range = 0.0%), whereas the hospital-based acute care rate was 2.1% (interquartile range = 0.6%), with few centers (N = 36) having no observed encounters. No correlation was noted between From the *Department of Surgery, Boonshoft School of Medicine, Wright State University, Dayton, OH; wCenter for Outcomes Research and Evaluation; and zRobert Wood Johnson Foundation Clinical Scholars Program, Section of General Internal Medicine, and Cancer Outcomes Policy and Effectiveness Research (COPPER) Center, Yale University School of Medicine, New Haven, CT. The views expressed in this article are those of the authors and do not reflect the official policy of the United States Air Force, Department of Defense, Centers for Medicare & Medicaid Services, or the US Government. I.R. works under contract with the Centers for Medicare & Medicaid Services to develop and maintain performance measures, and is supported by an Early Career Fellowship co-funded by the National Health and Medical Research Council of Australia and the National Heart Foundation of Australia. The remaining authors declare no conflict of interest. Reprints: Justin P. Fox, MD, MHS, Miami Valley Hospital, One Wyoming Street, Suite 7000 WCHE, Dayton, OH 45409. E-mail: justin_p_fox@ yahoo.com. Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Website, www.lww-medical care.com. Copyright r 2014 by Lippincott Williams & Wilkins ISSN: 0025-7079/14/5209-0801
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the risk-standardized hospital transfer and hospital-based acute care rates (volume weighted correlation coefficient = 0.04, P = 0.16). Conclusions: Patients more frequently experience hospital-based acute care encounters after colonoscopy than the need for immediate hospital transfer. Broadening existing quality measures to include hospital-based acute care in the postdischarge period may provide a more complete measure of quality. Key Words: hospital based acute care, ambulatory surgery center, quality measurement (Med Care 2014;52: 801–808)
Q
uality improvement initiatives, including value-based purchasing programs, have been evaluating health care outcomes and assessing relative performance among hospitals and providers for several years. Most notably, a hospital’s mortality and readmission rates for selected conditions are publically reported and financial reimbursement adjusted based on performance. As the delivery of health care shifts from the inpatient to the outpatient setting,1 quality measurement efforts have followed. Beginning in 2012, the Centers for Medicare and Medicaid Services (CMS) expanded quality measurement efforts to ambulatory surgery centers (ASC).2,3 These efforts require ASC to self-report 5 quality measures, including the rate at which patients are immediately transferred to a hospital rather than discharged home. This measure is meant to serve as a surrogate marker for serious adverse events. For colonoscopy, which accounts for nearly 1 in every 5 discharges from ASC,4 the immediate hospital transfer rates may not be an accurate barometer for the quality of care provided. Although colonoscopy can often be accomplished safely, the procedure is associated with a measurable rate of adverse events both during the procedure and after discharge.5,6 Prior studies have found patients may re-present to health care after being discharged home for diagnoses ranging from pain and nausea to gastrointestinal bleeding and colonic perforation.7–11 Although some symptoms may be expected following colonoscopy, acute-onset symptoms that prompt presentation to medical attention, whether as return ASC encounters, emergency department visits, or hospital admissions, can adversely affect a patient’s quality of life and result in additional health care expenditures.10 As medical and surgical procedures are migrating to ambulatory setting, including ASC and hospital-based outwww.lww-medicalcare.com |
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patient departments, a critical assessment of accompanying quality metrics is needed to determine their ability to adequately inform patient and payer decision making. Currently, little is known regarding the frequency or variation in hospital transfer rates when applying contemporary risk standardization methods or if focusing on this time period may miss important adverse events after home discharge. If the hospital transfer rate is exceptionally uncommon, misses a substantial number of events, or varies little across ambulatory centers, its ability to provide meaningful information for quality assessment is limited. To this end, we analyzed data from patients undergoing colonoscopy in ASC and hospital-based outpatient departments across 4 states to determine variation in risk standardized, immediate hospital transfer and hospital-based acute care rates within 14 days of discharge. We hypothesized that immediate hospital transfer would be uncommon and underestimate the frequency of adverse events following colonoscopy.
METHODS We conducted a retrospective cohort study using administrative data from the 2009–2010 California (CA), Florida (FL), Nebraska (NE), and New York (NY) state ambulatory surgery, inpatient, and emergency department databases. These data are compiled at the state level from administrative, clinical, and billing information, standardized across states, and then made available through the Healthcare Cost and Utilization Project (HCUP).12 The ASC database is either a census of discharges from free-standing ASC and hospital-based outpatient departments (CA, FL, and NY) or free-standing ASC alone (NE). The inpatient databases are a census of discharges from all acute care, non-federal, community hospitals, whereas the emergency department databases are a census of emergency department encounters which do not result in hospital admission. However, if a patient presents to the hospital emergency department and is subsequently admitted to the hospital, the patient would be captured by the inpatient database. Each discharge abstract contains at least 9 Current Procedural Terminology (CPT) or International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes, 15 diagnostic ICD-9-CM codes, and information about patient demographics, anticipated payer, and discharge disposition. These states were selected for analysis because of their geographic diversity, large populations, and availability of the encrypted identifiers which allow patients to be followed over time and across health care settings. In 2010, the population of these states accounted for 25% of the total US population.13
Patient Selection From the ASC databases, we identified discharges for state residents at least 18 years of age, had an encrypted patient identifier, and underwent colonoscopy as their primary procedure (CPT-4 codes 45378, 45380, 45381, 45383, 45384, 45385, 45391, and HCPCS codes G0105, G0121) between July 2009 and September 2010. From this population (N = 1,379,549), we sequentially excluded discharges with a concurrent procedure code for upper endoscopy
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(N = 182,408) and where the discharge disposition was recorded as missing, death, or left against medical advice (N = 1179). To create a more homogenous sample of patients and for consistency with prior reports,7 we excluded patients with a diagnosis of inflammatory bowel disease (N = 25,573) or recent diagnoses of diverticulitis (N = 10,517) or colorectal cancer (N = 7203). Finally, we excluded ASC reporting 1 of these outcomes within 14 days, we also calculated event rates per 1000 discharges with 95% confidence intervals (CI). Finally, we evaluated the variation in risk-standardized outcomes across ASC by creating 2-level (patient and ASC) hierarchical logistic regression models for each outcome, using similar methods to those used by the CMS.19 The previously described covariates were entered into 3 separate logistic regression models, 1 for each outcome. Using a backward selection process with a retention P-value of 0.05, we created the most parsimonious models. All authors then reviewed these variables to ensure they were clinically appropriate. The final variables for risk adjustment included: age, sex, anticipated primary payer, 26 medical comorbidities, discharge diagnosis, and whether a biopsy or polypectomy was performed. Models also included ASC-level random intercepts to account for clustering of patients within ASC and permit separation of the within and between ASC variation in outcomes after accounting for patient characteristics. The predicted-to-estimated ratio obtained from these models was then multiplied by the mean unadjusted outcome rate among all ASC included in the study to yield the risk-standardized rates. Finally, we conducted these same analyses among 3 subgroups: the non-Medicare population, discharges from free-standing ASC, and the “screening” colonoscopy cohort which was identified using diagnostic coding. All analyses were conducted using SAS version 9.3 (SAS Institute, Cary, NC). Because this study used publicly available data that does not include patient identifiers, it was considered exempt from review by the Wright State University Institutional Review Board and Yale University Human Investigations Committee.
RESULTS The final sample included 1,137,381 discharges from 1019 ASC in 4 states. Over half of the discharges were for women (52.5%) without significant medical comorbidity (77.2%) and with private insurance (56.0%). A biopsy or polypectomy was performed during more than half (54.8%) of the procedures. The most common primary diagnosis associated with the colonoscopy discharge was “screening” (31.9%) or “benign neoplasms” (28.7%; Table 1).”
Description of Hospital Transfer and Hospitalbased Acute Care Within 14 Days Relatively few discharges were associated with an immediate hospital transfer (N = 344; 0.03%). When a hospital transfer did occur, the most commonly associated diagnoses were for accidental operative laceration, abdominal pain, and cardiopulmonary complications. Conversely, 24,513 discharges (2.2%) were associated with a hospitalr
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No. discharges Age, median (SD) (y) Sex Male Female Missing Race and ethnicity White Black Hispanic Other Missing Primary payer Medicare Medicaid Private Other State of residence California Florida Nebraska New York Free-standing ambulatory surgery center Comorbid medical conditions No conditions 1–2 conditions 3–4 conditions Z5 conditions Diagnosis associated with colonoscopy Screening Benign neoplasms Diverticulosis Other gastrointestinal disorders Gastrointestinal hemorrhage All other diagnoses Colonoscopy with biopsy
1,137,381 (100.0) 60.0 (12.3) 527,949 (46.4) 596,624 (52.5) 12,808 (1.1) 733,160 89,795 128,915 98,651 86,860
(64.5) (7.9) (11.3) (8.7) (7.6)
374,888 61,595 637,350 63,548
(33.0) (5.4) (56.0) (5.6)
327,963 512,859 13,072 283,487 546,003
(28.8) (45.1) (1.2) (24.9) (48.0)
878,326 217,253 32,653 9,149
(77.2) (19.1) (2.9) (0.8)
362,842 326,935 64,362 107,495 76,746 199,001 622,847
(31.9) (28.7) (5.7) (9.5) (6.8) (17.5) (54.8)
based acute care encounter within 14 days of discharge for a rate of 24.2 encounters (95% CI, 23.9–24.5)/1000 discharges (Fig. 1). Hospital admissions [0.9%; 9.7 (9.5–9.8)/1000] and emergency department visits [1.3%; 12.6 (12.4–12.8)/1000] occurred with similar frequency, but for different associated diagnoses. Hemorrhage, diverticulitis, benign neoplasms, accidental operative laceration, and coronary artery disease were common diagnoses associated with hospital admission. For emergency department visits, symptoms such as abdominal or chest pain and urinary tract infection were more common. Finally, a subsequent ASC encounter due to bleeding within 14 days of colonoscopy occurred with a frequency similar to hospital transfer (0.03%; Table 2).
Factors Associated With Hospital-based Acute Care From the final model used for risk adjustment, several variables were associated with more frequent hospital-based acute care within 14 days of discharge. Regarding the type of colonoscopy, those who had an associated diagnosis other than “screening” or had a concurrent biopsy performed [adjusted odds ratio (AOR) = 1.32 (95% CI, 1.29–1.36)] more frequently had a hospital-based acute care encounter www.lww-medicalcare.com |
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FIGURE 1. Frequency of hospital-based acute care encounters (y-axis) in the overall population according to the number of days before or after colonoscopy (x-axis).
after discharge. Differences were also noted across payers. With Medicare as the reference, discharges where Medicaid [AOR = 1.38 (95% CI, 1.32–1.45)] was the anticipated primary payer was associated with more frequent hospital-based acute care encounters, whereas Private [AOR = 0.59 (0.57–0.61)] forms of insurance were associated with less frequent encounters. Patient comorbidity was also related to these postdischarge events, including several cardiopulmonary
conditions and a history of metastatic cancer [AOR = 2.18 (1.72–2.75)]. Notably, discharges where the patient had known fluid or electrolyte disorders [AOR = 1.90 (1.76–2.06)] were associated with more frequent hospital-based acute care encounters (Table 3). Similar findings were noted in the model for immediate hospital transfer (see Supplemental Digital Content 3, http://links.lww.com/MLR/A752 for full results of the immediate hospital transfer model).
TABLE 2. Hospital-based Acute Care and Adverse Events Within 14 Days of Outpatient Colonoscopy Rate/1000 discharges (95% CI)z N* (%w) Hospital-based acute care Immediate hospital transfer
24,513 (2.2)
Estimate LCI UCI 24.2
23.9
Most common
Second
Third
Hemorrhage complicating a procedure 0.34 Accidental operative laceration 0.33 Rectal and anal hemorrhage
Abdominal pain
Diverticulitis
24.5
344 (0.0)
0.30
0.27
Ambulatory 327 (0.0) surgery center encounter Hospital admission 10,533 (0.9)
0.29
0.26
9.7
9.5
9.8
12.6
12.4
12.8
Emergency 14,407 (1.3) department visit
Associated diagnosesy
Hemorrhage complicating a procedure Abdominal pain
Fourth Chest pain
Atrial Abdominal pain fibrillation
Fifth Gastrointestinal hemorrhage
Respiratory Surgical complications complications: cardiac Gastrointestinal Surgical hemorrhage complications: gastrointestinal tract Accidental Coronary artery operative disease laceration Chest pain Gastrointestinal hemorrhage
Melena
Hemorrhage complicating a procedure Diverticulitis Benign neoplasm of the colon
Urinary tract Rectal and anal infection hemorrhage
*Number of patients in the total sample experiencing at least 1 event. w Percentage of patients in the total sample experiencing at least 1 event. z Number of events per 1000 discharges experienced by the total population. y On the basis of first listed ICD-9-CM diagnostic code.
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TABLE 3. Results From the Hierarchical Logistic Regression Model for Hospital-based Acute Care Within 14 Days of Colonoscopy Diagnosis associated with colonoscopy Screening Benign neoplasms Diverticulosis Other gastrointestinal disorders Gastrointestinal hemorrhage All other diagnoses Colonoscopy with biopsy Age (y) Sex Male Female Primary payer Medicare Medicaid Private Other Medical comorbidity Congestive heart failure Cardiac arrhythmia Valvular disease Peripheral vascular disorders Hypertension uncomplicated Other neurological disorders Chronic pulmonary disease Diabetes uncomplicated Diabetes complicated Renal failure Liver disease Peptic ulcer disease, excluding bleeding Lymphoma Metastatic cancer Solid tumor without metastasis Rheumatoid arthritis/collagen vascular disease Coagulopathy Obesity Weight loss Fluid and electrolyte disorders Blood loss anemia Deficiency anemia Alcohol abuse Drug abuse Psychoses Depression
N* (%w)
Odds Ratio
Lower 95% CI
Upper 95% CI
362,842 (1.5) 326,935 (2.3) 64,362 (2.5) 107,495 (2.7) 76,746 (2.5) 199,001 (2.7) 622,847 (2.4) —
1.36 1.58 1.60 1.60 1.62 1.32 0.99
Reference 1.31 1.49 1.53 1.52 1.55 1.29 0.99
1.42 1.68 1.68 1.69 1.68 1.36 0.99
527,949 (2.1) 596,624 (2.2)
1.08
Reference 1.05
1.11
374,888 61,595 637,350 63,548
(2.8) (4.5) (1.5) (2.3)
1.38 0.59 0.83
Reference 1.32 0.57 0.78
1.45 0.61 0.88
6757 19,776 6769 5239 169,371 6254 34,781 62,379 3847 7885 6484 1701 978 945 4094 4227 1932 16,936 8863 8947 1698 14,046 3153 1977 1770 16,315
(10.6) (6.8) (5.7) (8.0) (3.6) (8.0) (6.2) (4.6) (10.3) (9.0) (7.0) (9.2) (6.9) (10.8) (6.4) (6.6) (10.7) (5.1) (6.0) (13.0) (8.7) (4.8) (10.3) (14.3) (11.1) (7.1)
1.25 1.56 1.11 1.24 1.32 1.49 1.54 1.30 1.31 1.49 1.30 1.53 1.67 2.18 1.46 1.47 1.21 1.11 1.51 1.90 1.41 1.31 1.47 1.78 1.53 1.51
1.13 1.46 0.99 1.11 1.28 1.35 1.46 1.25 1.16 1.35 1.17 1.28 1.29 1.72 1.27 1.29 1.03 1.02 1.37 1.76 1.17 1.20 1.29 1.54 1.30 1.41
1.38 1.67 1.25 1.39 1.37 1.65 1.62 1.37 1.49 1.64 1.46 1.84 2.18 2.75 1.69 1.67 1.43 1.20 1.66 2.06 1.70 1.42 1.69 2.06 1.81 1.62
C-statistic = 0.66. *Number of patients in the sample within given variable. w Percentage of patients within given variable experiencing the outcome. CI indicates confidence interval.
Variation in Hospital Transfer and Hospitalbased Acute Care Across Centers At the ASC level, the risk-standardized hospital transfer rate was low (median = 0.0%, interquartile range = 0.0%), with minimal variation across centers, and nearly 89.2% of centers had no hospital transfers. Conversely, the risk-standardized hospital-based acute care rate was more common (median = 2.1%, interquartile range = 0.6%), had more variability, and fewer centers (3.5%) had no observed encounters. No correlation was noted between the risk-standardized hospital transfer and hospital-based acute care rates (volume-weighted correlation coefficient = 0.04, P = 0.16). After accounting for differences in patient case-mix across facilities, the composite measure including immediate hospital transfer and hospitalr
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based acute care in the postdischarge period varied >3-fold across ASC (median = 2.2%, 1st percentile = 1.2%, 99th percentile = 3.7%; Fig. 2).
Subgroup Analysis The same analyses described above were conducted among the non-Medicare population (discharges = 762,493, centers = 1018), those treated at free-standing ASC (discharges = 559,075, centers = 365), and among the “screening” colonoscopy cohort (discharges = 362,842, centers = 997). Although the exact transfer and hospital-based acute care rates differed slightly among these subgroups, the overall finding that hospital-based acute care rates were much larger than hospital transfer rates was consistent with the overall www.lww-medicalcare.com |
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FIGURE 2. A, Variation in ambulatory surgery centers’ risk-standardized hospital transfer rate at the time of discharge following colonoscopy. B, Variation in ambulatory surgery centers’ risk-standardized hospital-based acute care rate within 14 days of discharge following colonoscopy.
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sample (see Supplemental Digital Content 4, http://links. lww.com/MLR/A753 for detailed results of the subgroup analyses).
DISCUSSION Outpatient colonoscopy remains a safe procedure; however, monitoring hospital transfer rates as a measure of quality will fail to identify 98% of hospital-based acute care utilization after home discharge. As scrutiny of outpatient quality and outcomes increases, it is essential to assess the validity and potential impact of proposed performance measures. The acute care events that our approach identified represent important patient outcomes, as they were often associated with symptoms or diagnoses likely related to the procedure including bleeding and perforation, and may add to the costs of care. The utility of hospital transfer rates as a quality measure is further limited by the lack of variation in this outcomes noted across centers, thus preventing meaningful stratification of centers into those that are high or low performing. Broadening the current quality measure beyond the immediate discharge disposition may be warranted to more completely capture adverse events related to care and more accurately determine ASC performance. Failing to account for these postdischarge events may misinform health care payers and patients by not accurately identifying centers as high or low performing. The diagnoses associated with the need for immediate hospital transfer are similar to those seen among patients discharged home and returning to the hospital, further supporting their inclusion in a quality measure. Among those transferred to the hospital, cardiorespiratory complications, gastrointestinal perforation, and abdominal pain were common diagnoses. These diagnoses are likely related to the bowel preparation, sedation for the procedure,11 or the procedure itself.6,20 Yet, it is important to note that patients who were discharged home and readmitted within 14 days had similar diagnoses. This raises the possibility that those transferred to the hospital from an ASC represents a cohort of patients for whom a complication of care was identified before discharge. Conversely, patients who were discharged home only to return to the hospital may represent a cohort of patients with missed complications at the time of the procedure. The failure of current quality measures3 that focus on the immediate hospital transfer fail to capture adverse events occurring after a home discharge has important implications for quality measurement efforts, health care providers, and ultimately patients. First, this measure may have unintended consequences whereby health care providers err on the side of home discharge rather than hospital transfer for further evaluation for patients in whom an obvious disposition is not clear. If the patient then develops an adverse event at home prompting a return to the hospital, the encounter would not count toward an adverse event for the ambulatory surgery but has the potential to be detrimental for patients. Second, ASC with liberal home discharge policies, whether appropriate or not, will seem to be better performing than more conservative centers with similar hospital-based acute care rates. r
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If performance on the current hospital transfer measure is then tied to financial reimbursement, these ASC with higher hospital transfer rates but lower hospital-based acute care rates could be unfairly penalized. Measuring hospital-based acute care after outpatient colonoscopy may have some advantages over other proposed colonoscopy quality measures, including patient satisfaction scores21 and technical competence as reflected by cecal intubation and colonoscopy completion rates.22 Although patient surveys provide important information about the patient experience, broad implementation would require significant efforts to develop, test, and implement standardized colonoscopy-specific surveys across ASC. Cecal intubation and colonoscopy completion rates are critically important to the effectiveness of colonoscopy; however, these outcomes would likely require self-reporting posing a conflict of interest and sacrificing objectivity. Monitoring the postdischarge period may provide an opportunity to compare outcomes across centers with a low burden to individual ASC while maintaining objectivity. This is not without its own limitations, including attributing all hospital-based acute care visits to the colonoscopy and the potential for capturing visits as part of a planned treatment course (ie, colon resection after a cancer is diagnosed). Further efforts should develop a postdischarge algorithm to maximize capturing events which are likely complications of care while minimizing identification of planned or unrelated health care contacts. The variation in hospital-based acute care encounters across ASC likely represents a modifiable outcome. Health care providers in ASC have previously recognized patient’s needs after discharge23–25 and described practices throughout the patient encounter which may mitigate hospital-based acute care utilization after discharge. These practices begin before the procedure with ensuring the patient has an adequate indication for the colonoscopy and then identifying patients at risk for periprocedural complications.26 In the current study, patients with significant heart disease including arrhythmias, cardiac valvular disease, and heart failure were more likely to return to the hospital.27 This may be reflected in diagnoses of cardiac arrhythmias and chest pain frequently being seen associated with hospital return. Further, patients with fluid and electrolyte disorders, renal failure, and liver disease were also more likely to return to the hospital. This raises the question of how well the bowel preparation is tolerated in these patients.28 During the procedure, it is important to ensure anesthesia is provided safely29,30 and that the patient recovers from these medications before discharge to minimize adverse events.31 Finally, after patients are discharged some centers have provided telephonic follow-up to monitor recovery, provided patients with after-hours contact information, and focused on patient education regarding expected symptoms following colonoscopy.21,32 The current study should be interpreted in the context of several limitations. First, patients who were readmitted to a hospital outside their state of residence could not be accounted for in this study. In addition, if patients lived in “border towns” and underwent colonoscopy in one state, but sought postdischarge care in another, these events could be missed leading www.lww-medicalcare.com |
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to an underestimation of postdischarge hospital-based acute care. To limit the influence of this factor, we restricted our population to state residents. Second, we did not include visits to physician offices in the 7 days following colonoscopy. Therefore, if adverse events were effectively managed in the physician’s office without subsequent emergency department visits or hospital admissions, they would not be included in this study further leading to an underestimation of adverse events. Finally, the dataset utilized is subject to the accuracy of the coding provided. Identifying specific complications from administrative data can be problematic.33 By focusing on the frequency of health care contacts experienced by patients following the procedure, we do not rely on the accuracy of specific ICD-9-CM code selection for identifying patients. In conclusion, hospital transfer at the time of discharge fails to adequately capture adverse events related to outpatient colonoscopy. Broadening the quality measurement period to the 14 days following discharge may provide a more patient-centered outcome while better assessing the quality of care provided and a more meaningful determination of “high” and “low” performing centers. REFERENCES 1. Manchikanti L, Singh V, Hirsch JA. Saga of payment systems of ambulatory surgery centers for interventional techniques: an update. Pain Physician. 2012;15:109–130. 2. Rollins G. Final five: ASCs told to target patient safety. Hosp Health Netw. 2007;81:53–54, 56, 51. 3. Centers for Medicare & Medicaid Services (CMS), HHS. Medicare program; revised payment system policies for services furnished in ambulatory surgical centers (ASCs) beginning in CY 2008. Final rule. Fed Regist. 2007;72:42469–42626. 4. Russo A, Elixhauser A, Steiner C, et al. Utilization Project Statistical B. Hospital-Based Ambulatory Surgery, 2007: Statistical Brief #862006. 5. Day LW, Kwon A, Inadomi JM, et al. Adverse events in older patients undergoing colonoscopy: a systematic review and meta-analysis. Gastrointest Endosc. 2011;74:885–896. 6. Ko CW, Riffle S, Michaels L, et al. Serious complications within 30 days of screening and surveillance colonoscopy are uncommon. Clin Gastroenterol Hepatol. 2010;8:166–173. 7. Warren JL, Klabunde CN, Mariotto AB, et al. Adverse events after outpatient colonoscopy in the Medicare population. Ann Intern Med. 2009;150:849–857, W152. 8. Stock C, Ihle P, Sieg A, et al. Adverse events requiring hospitalization within 30 days after outpatient screening and nonscreening colonoscopies. Gastrointest Endosc. 2013;77:419–429. 9. Rabeneck L, Saskin R, Paszat LF. Onset and clinical course of bleeding and perforation after outpatient colonoscopy: a population-based study. Gastrointest Endosc. 2011;73:520–523. 10. Leffler DA, Kheraj R, Garud S, et al. The incidence and cost of unexpected hospital use after scheduled outpatient endoscopy. Arch Intern Med. 2010;170:1752–1757. 11. Cooper GS, Kou TD, Rex DK. Complications following colonoscopy with anesthesia assistance: a population-based analysis. JAMA Intern Med. 2013;173:551–556. 12. HCUP. Overview of healthcare cost and utilization project, 2012. Available at: http://www.hcup-us.ahrq.gov/overview.jsp. Accessed May 8, 2012.
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13. US Census Bureau. Summary File 1. 2010. Available at: http:// www.census.gov/2010census/. Accessed October 10, 2013. 14. AGA. AGA quality and outcomes measures. Available at: http://www. gastro.org/practice/quality-initiatives/performance-measures/aga-qualityand-outcomes-measures. Accessed August 3, 2013. 15. Rex DK, Petrini JL, Baron TH, et al. Quality indicators for colonoscopy. Am J Gastroenterol. 2006;101:873–885. 16. HCUP. Clinical classifications software (CCS) for ICD-9-CM, 2012. Available at: http://www.hcup-us.ahrq.gov/toolssoftware/ccs/ccs.jsp. Accessed April 16, 2012. 17. Elixhauser A, Steiner C, Harris DR, et al. Comorbidity measures for use with administrative data. Med Care. 1998;36:8–27. 18. Quan H, Sundararajan V, Halfon P, et al. Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data. Med Care. 2005;43:1130–1139. 19. Krumholz HM, Lin Z, Drye EE, et al. An administrative claims measure suitable for profiling hospital performance based on 30-day all-cause readmission rates among patients with acute myocardial infarction. Circ Cardiovasc Qual Outcomes. 2011;4:243–252. 20. Ko CW, Riffle S, Shapiro JA, et al. Incidence of minor complications and time lost from normal activities after screening or surveillance colonoscopy. Gastrointest Endosc. 2007;65:648–656. 21. Sewitch MJ, Dube C, Brien S, et al. Patient-identified quality indicators for colonoscopy services. Can J Gastroenterol. 2013;27: 25–32. 22. Hewett DG, Rex DK. Improving colonoscopy quality through healthcare payment reform. Am J Gastroenterol. 2010;105:1925–1933. 23. Mezei G, Chung F. Return hospital visits and hospital readmissions after ambulatory surgery. Ann Surg. 1999;230:721–727. 24. Twersky R, Fishman D, Homel P. What happens after discharge? Return hospital visits after ambulatory surgery. Anesth Analg. 1997;84: 319–324. 25. Warner MA, Shields SE, Chute CG. Major morbidity and mortality within 1 month of ambulatory surgery and anesthesia. JAMA. 1993;270: 1437–1441. 26. Mehta PP, Kochhar G, Kalra S, et al. Can a validated sleep apnea scoring system predict cardiopulmonary events using propofol sedation for routine EGD or colonoscopy? A prospective cohort study. Gastrointest Endosc. 2014;79:436–444. 27. Rex DK, Bond JH, Winawer S, et al. Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: recommendations of the US Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol. 2002;97: 1296–1308. 28. Enestvedt BK, Tofani C, Laine LA, et al. 4-Liter split-dose polyethylene glycol is superior to other bowel preparations, based on systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2012;10: 1225–1231. 29. Bui AH, Urman RD. Clinical and safety considerations for moderate and deep sedation. J Med Pract Manage. 2013;29:35–41. 30. Metzner J, Domino KB. Risks of anesthesia or sedation outside the operating room: the role of the anesthesia care provider. Curr Opin Anaesthesiol. 2010;23:523–531. 31. Trevisani L, Cifala` V, Gilli G, et al. Post-Anaesthetic Discharge Scoring System to assess patient recovery and discharge after colonoscopy. World J Gastrointest Endosc. 2013;16:502–507. 32. Pennsylvania Patient Safety Reporting System. Unanticipated care after discharge from ambulatory surgical facilities, 2005. Available at: http:// patientsafetyauthority.org/ADVISORIES/AdvisoryLibrary/2005/dec2(4)/ Documents/01b.pdf. Accessed April 11, 2012. 33. Lawson EH, Louie R, Zingmond DS, et al. A comparison of clinical registry versus administrative claims data for reporting of 30-day surgical complications. Ann Surg. 2012;256:973–981.
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