This study used data from a nationally representative survey of physicians conducted in 2006–2007 and compared them to selected results from an earlier national survey14
to show that physicians' CRC screening recommendations and practices have changed substantially over a 7-year period. Colonoscopy is now the most frequently recommended test; in 1999–2000, it was FOBT. Moreover, despite national guidelines that list multiple test options for CRC screening and that promote the precept of patient choice in deciding on an acceptable screening strategy,18
this study documents declines in the percentages of physicians who routinely recommend FOBT, sigmoidoscopy, and DCBE, with the most dramatic decline for sigmoidoscopy. The patterns of and trends in physician recommendation reported in this study parallel those for CRC test use as documented in the general population and among Medicare beneficiaries.19–21
Another notable finding is that, consistent with physicians' reduced propensity to recommend FOBT, sigmoidoscopy, and DCBE, considerably fewer in 2006–2007 than in 1999–2000 perceived these tests to be very effective in reducing CRC mortality, even though no new evidence has been published in the last 7 years indicating that the tests have less effectiveness than previously established. In contrast, the percentage of physicians who believe that colonoscopy is very effective in reducing CRC mortality increased by nearly ten percentage points between 1999–2000 and 2006–2007.
Although national guidelines in place at the time of this study16,22,23
specified four different tests as acceptable CRC screening options (i.e., FOBT, sigmoidoscopy, colonoscopy, and DCBE) and recommended that physicians present those test options to patients in an informed/shared decision-making process, study results indicate that in practice most physicians are applying the guidelines selectively. More than 50% routinely recommend two tests (and no others), while 17% recommend only one test. Fewer than 10% routinely recommend all four test modalities. These findings are noteworthy in light of research showing that patients have distinct preferences for CRC screening tests24–28
and that, in practices where only one CRC screening test is offered, many patients do not follow through to obtain screening because of concerns about the test.29
Moreover, a growing body of work indicates that patient preferences for CRC screening tests vary according to the information provided about costs and procedure risks as well as by income level and race/ethnicity.30–32
Another practice change documented by this study is a dramatic decline in the percentage of physicians who perform sigmoidoscopy. In 1999–2000, 29% of U.S. physicians reported that they performed this procedure in their practices.14
The present study shows that only 4% do so. This is a large decline over a relatively short time period. This finding provides important context for interpreting data from national surveys of the general population and the Medicare program, which show substantially reduced sigmoidoscopy use since 2000.19–21
Highly publicized editorials and a 2000 American College of Gastroenterology guideline advocating colonoscopy as the preferred CRC screening strategy may have motivated many physicians to stop performing sigmoidoscopies.33,34
Few studies have examined physicians' specific reasons for performing or not performing this procedure. Low procedure volumes, inadequate reimbursement, and lack of time and support staff have been documented as barriers to physicians' provision of sigmoidoscopy in their practices.14,35,36
Survey results from 1999–2000 showed that many U.S. physicians had adopted nonstandard CRC screening practices such as recommending screening at earlier starting ages or shorter intervals—or both—for asymptomatic, average-risk patients.14
The present study indicates modest improvements in the percentages of physicians who identify guideline-consistent starting ages and test intervals for the CRC screening modalities that they routinely recommend. Nevertheless, many physicians continue to recommend that screening begin at age <50 years or be repeated at too-frequent intervals. This is particularly true for colonoscopy, with 43% of physicians who recommend it indicating that they believe patients should undergo the procedure at intervals more frequent than once every 10 years. The propensity of endoscopists to recommend repeat colonoscopy at too-frequent intervals also has been documented.37,38
The overuse of colonoscopy has implications for patients' exposure to procedure risks as well as for national capacity to achieve higher levels of CRC screening and follow-up among age-eligible adults. Future work will examine factors associated with physicians who report nonguideline-consistent CRC screening practices.
Another important study finding is that many physicians' practices lack office systems to support CRC screening. Slightly more than 60% reported that their practice had implemented CRC screening guidelines, and 28% indicated that their office uses a full or partial EMR. Fewer than one third indicated that their practice has a reminder system to prompt the physician about CRC screening, while fewer than a quarter use reminders to prompt patients. Few physicians receive reports on CRC screening rates for their patient panel. The importance of office systems to increasing CRC screening rates in practice is well established.12,13;39–41
In particular, the great potential of EMRs in promoting appropriate screening within primary care practices has been noted.42
Given the heavy reliance of physicians on referral to other providers for endoscopy and the limited office systems to support CRC screening recommendations/activities documented by this study, it is not surprising that gaps remain between high levels of physician recommendation and actual CRC screening rates.5
A limitation of this study is that it is based on physicians' reports of their recommendations and practices; self-reported data were not validated with other data sources such as medical records or claims. Medical-record and claims data, however, may not be entirely accurate sources of information about physicians' CRC screening recommendations and practices; under-ascertainment of screening practices in these data sources has been documented.43,44
Another limitation is that, for physicians who recommended more than one test modality, the precise patterns of use of the multiple modalities (e.g., FOBT or colonoscopy versus FOBT and colonoscopy) are unknown. This is because the survey items ascertaining physicians' recommendations did not ask about test combinations or preferences for one test over others.
Study strengths include the use of a nationally representative survey with a large sample size and high response rate. Moreover, surveys such as this one can provide more detailed information about physicians' recommendations and practices than is typically available in medical-record or claims data.
Raising CRC screening rates remains a public health challenge. Modeling has shown that CRC mortality in the U.S. could be reduced by 50% within the next decade, largely through increased screening uptake.45
Yet national surveys of the general population continue to show suboptimal screening use, along with lack of awareness of the need for screening and lack of recommendation from a doctor to obtain it. These continue to be noted as key reasons why many age-eligible adults are not screened.5
At a time when many physicians offer patients only one or two of the screening options (e.g., colonoscopy and FOBT), one updated guideline has expanded the menu of recommended test options to include CT colonography and fecal DNA testing2
; another states that patients may no longer need screening when they become aged 75 or 85 years.3
How physicians might operationalize these new guidelines in practice, particularly the more extensive test menu and suggested stopping ages, requires future study.