Are Physicians Doing Too Much Colonoscopy? A National Survey of Colorectal Surveillance after Polypectomy

Context Colonoscopic surveillance following colon polypectomy is costly in terms of money and manpower. Clinical practice guidelines recommend different surveillance intervals after polypectomy, depending on the size, number, and histologic characteristics of the polyps identified; however, actual adherence to the guidelines is unknown. Contribution This nationally representative survey of gastroenterologists and general surgeons shows that physicians recommend surveillance colonoscopy much more frequently than clinical guidelines suggest, especially for hyperplastic polyps and small adenomas. Implications Unjustified overuse of surveillance colonoscopy after polypectomy seems to be widespread; this situation threatens to overwhelm the money and resources available for health care maintenance. The Editors Colonoscopy is being increasingly used in colorectal cancer screening (1, 2). This increased usage is based on recent studies and commentary (3-5), the endorsement of organizations that develop guidelines (6-8), celebrity promotion (9), and third-party payer reimbursement (10, 11). Polyp detection from the performance of colonoscopy is likely to increase surveillance, which has concerned some policymakers because physician manpower and resources may not be adequate to meet the demand for colonoscopy (2, 12-15). Some researchers have suggested redirecting resources from low-risk to high-risk persons to increase the overall effect of programs of colorectal cancer screening and surveillance (6). Screening studies for colorectal cancer have shown adenoma detection in 20% to 30% of average-risk persons age 50 years and older (3, 4, 16). However, almost three quarters of persons with lesions identified during screening have only 1 to 2 small (<1 cm) tubular adenomas (3) (Pickhardt PJ. Personal communication), for which subsequent risk for colorectal cancer may be minimal (17). A hyperplastic polyp, a benign nonneoplastic lesion, is often identified in 10% or more of persons screened (3, 4, 18-21). In 1999, the surveillance of neoplasia accounted for approximately 25% of the estimated 4.4 million colonoscopies performed annually by gastroenterologists in the United States (14, 22). In persons with lesions that do not confer an increased future risk for colorectal cancer, such as hyperplastic polyps or small adenomas, surveillance may be overperformed (6, 14, 20, 21, 23). Clinical practice guidelines for adenoma surveillance typically recommend colonoscopy at 3 years after finding a large adenoma and at 3 to 5 years after detection of a small adenoma; surveillance is not recommended for a hyperplastic polyp (Table 1) (23-27). Table 1. Guidelines for Colonoscopic Surveillance Intervals after Polypectomy To understand the physician and health system factors that influence the effective use of colorectal cancer screening and surveillance, the National Cancer Institute conducted the Survey of Colorectal Cancer Screening Practices in Health Care Organizations. In this report, we describe how gastroenterologists and general surgeons recommend surveillance of various polyps detected during screening colonoscopy and compare their recommendations to published clinical practice guidelines from medical societies and professional organizations. Methods Survey Content and Participants The National Cancer Institute, in collaboration with the Centers for Medicare & Medicaid Services and the Centers for Disease Control and Prevention, conducted the Survey of Colorectal Cancer Screening Practices in Health Care Organizations (28). This survey was a comprehensive study of primary care and specialty physicians and health plan medical directors; it was designed to obtain nationally representative data on how colorectal cancer screening and surveillance were being conducted in the United States and to identify barriers to implementation in community practice. Using the American Medical Association's Physician Masterfile as the sampling frame, we surveyed a nationally representative sample of gastroenterologists and general surgeons in 1999 and 2000. The Masterfile contains demographic and practice-related data on all allopathic and almost all osteopathic physicians in the United States. Eligible respondents were identified from the database as being 75 years of age and younger, having an active license to practice medicine, and reporting patient care as their primary professional activity. We selected a systematic stratified random sample of 467 gastroenterologists and 467 general surgeons by using a fractional sampling interval after the sampling frame database was sorted by U.S. Census region (Northeast, North Central, South, and West), urban versus rural practice location, and sex of the physician. This sample size was selected to provide point estimates of population proportions within a 5% range at a 95% CI. Gastroenterologists were oversampled relative to their representation in the U.S. physician population to ensure sufficient numbers to make separate estimates by specialty. Of the initial sample, 131 physicians were subsequently determined to have retired or died, to not be currently practicing medicine, or to be unlocatable after an extensive search for current contact information. Exclusion of these physicians left 421 eligible gastroenterologists and 382 general surgeons. In the fall of 1999, we sent sampled physicians an advance mailing that contained a cover letter describing the objectives of the survey, letters of support from 5 medical societies and the U.S. Surgeon General, and a postcard with which physicians were asked to verify their specialty and practice status and indicate their preferred mode of response to the survey (mail, fax, telephone, or Internet). Physicians who responded to the advance mailing were sent a subsequent mailing that included the mail or fax version of the questionnaire or instructions on how to complete the survey by telephone or Internet, depending on their stated preference. Approximately 6 weeks later, a follow-up mailing that contained the questionnaire was sent to physicians who did not respond to the advance mailing. We made telephone calls to nonrespondents in March and early April 2000. All respondents received a prepaid $50 honorarium for their participation. The survey consisted of 40 questions and took approximately 20 minutes to complete. Items of the survey queried physicians regarding their beliefs about colorectal cancer screening and their opinions and practices specific to asymptomatic, average-risk patients. To assess physicians' recommendations for surveillance after polypectomy, the survey presented 4 clinical scenarios that described a healthy 50-year-old average-risk patient who had undergone colonoscopy during which 1 of the following lesions was detected: 1) hyperplastic polyp, 2) adenomatous polyp less than 1 cm in diameter, 3) adenomatous polyp 1 cm or greater in diameter, and 4) multiple ( 3) adenomas. The term surveillance was defined at the beginning of the survey: the procedure or procedures used to periodically examine the colon after detection and removal of a precancerous lesion by screening or other means. We asked physicians to indicate (in open-ended written responses) which of the following procedures they were most likely to recommend for surveillance after polypectomy: fecal occult blood test, flexible sigmoidoscopy, colonoscopy, double-contrast barium enema, or none (routine screening). They were also asked about the frequency with which the procedure would be performed, recorded as a specific time interval (for example, every 3 years) or a range of time (for example, 3 to 5 years). We used published recommendations as a guide to summarize these open-ended responses for analysis of time points and intervals. When intervals overlapped, we counted the responses in the category of the longer time interval. For example, a response of 2 to 4 years would be counted in the 3- to 5-year interval rather than the 1- to 3-year interval. Incomplete items in the survey were counted as a no response. We also asked physicians to rate (using a 3-point Likert scale) the familiarity of and the extent to which various published guidelines influenced their practice of colorectal cancer screening and surveillance. The categories in the scale were very influential, somewhat influential, and not influential. Similarly, we asked physicians to rate the influence of such factors as published clinical evidence, continuing medical education, and availability of reimbursement by third-party payers. Details of the survey design and administration, as well as the exact wording of all survey items, are available at www.healthservices. cancer.gov/surveys/colorectal/. Statistical Analysis We used descriptive statistics to examine recommended surveillance procedures, frequency intervals, and the influence of clinical practice guidelines and other factors. Ninety-five percent CIs were calculated for all estimates. We applied sample weights in the analysis to permit generalization of the results to the U.S. population of practicing gastroenterologists and general surgeons. We assigned each respondent a sample weight that accounted for selection into the sample as well as a slightly higher rate of nonresponse among physicians age 60 years and older. All analyses were based on weighted survey data, although weighted and unweighted data were very similar because of the high response rate. The similarity in results between the weighted and unweighted data also indicates that characteristics of physicians who responded to the survey did not differ greatly from those of physicians who did not respond. Analyses were stratified according to the 2 specialty groups represented in this survey. To provide nationally representative estimates and to account for the sampling design of the survey, all analyses were performed by using SUDAAN statistical software and survey weights (Research Triangle Instit