Predictors of poor adherence of U.S. gastroenterologists with colonoscopy screening and surveillance guidelines

Abstract

Background

The U.S. Multi-Society Task Force on Colorectal Cancer published guidelines for colonoscopy screening and surveillance in 2008 and affirmed them in 2012. Characteristics associated with guideline adherence among U.S. gastroenterologists have not been assessed.

Aims

Assess awareness and adherence of U.S. gastroenterologists with national guidelines for colonoscopy screening and surveillance and predictors of adherence to guidelines.

Methods

A web-based survey was administered to gastroenterologists in various practice settings across the United States.

Results

A total of 306 gastroenterologists completed the survey; 86% reported awareness of the guidelines. Low-volume colonoscopists (<20 /month) were less likely to be aware of the guidelines (OR 0.26, p=0.03) compared to high-volume colonoscopists (>100/month). Those completing training before 1990 were less likely to report following guidelines (OR 0.37, p=0.01). Adherence with guidelines was then assessed via clinical scenarios. Compared to physicians finishing training in 1991-2010, less adherence was seen in those finishing before 1990 (OR 0.75, p<0.001) or currently in training (OR 0.72, p=0.004). Compared to the Western U.S., less adherence was seen in the Midwest (OR 0.69, p=0.001), Northeast (OR 0.63, p<0.001), and South (OR 0.59, p<0.001). Lower adherence was seen among non-academic physicians (OR 0.72, p=0.001) and low-volume colonoscopists (OR 0.52, p<0.001).

Conclusions

There is poor adherence with colonoscopy screening and surveillance guidelines among U.S. gastroenterologists. Poor adherence was associated with being in training or finishing training before 1990, practicing in the South, non-academic settings, and low colonoscopy volume. These findings can target interventions for quality improvement in colorectal cancer screening and surveillance.

INTRODUCTION

Guidelines for colorectal cancer (CRC) screening and surveillance in the United States (U.S.) were initially developed in 1997, and updated in 2003 and 2006.[1] In 2008, the American Cancer Society (ACS), American College of Gastroenterology (ACG), American Gastroenterological Association (AGA), American Society for Gastrointestinal Endoscopy (ASGE) and the American College of Radiology (ACR) published joint guidelines for CRC screening and surveillance.[2] Recently in 2012, these guidelines were reaffirmed with stronger evidence.[3] These guidelines are based on best available evidence; however, their value in serving our patients is maximized by determining how current practicing gastroenterologists view them.

Since the development of the most recent guidelines in 2008 and 2012, there has not been a broad national survey of U.S. gastroenterologists regarding their practices in relation to the new guidelines. Furthermore, predictors for following these guidelines have not been assessed and could assist in targeting quality improvement measures. A prior survey based on the 2003 guidelines administered to 116 gastroenterologists at a board review course revealed that 49% percent answered questions related to the guidelines incorrectly, and 76% knew but disagreed with the guidelines.[4] A national survey of gastroenterologists and surgeons performed in 1999 and 2000 found that they reported recommending shorter intervals than suggested by the guidelines.[5] In 2010, a VA-only study of gastroenterologists testing the knowledge of 2006 guidelines showed a high proportion of physicians recommending intervals shorter or longer than guideline recommendations.[6] Two recent studies have shown that surveillance colonoscopy is overused in low-risk individuals and under-used in high risk patients in both academic and community settings.[7,8]

Our aims were: 1) to assess awareness and adherence to national colonoscopy screening and surveillance guidelines for colorectal cancer, and 2) to determine the factors associated with adherence to these guidelines.

METHODS

The Institutional Review Board at Washington University in St. Louis approved our study. A survey comprised of 12 multiple-choice questions was developed using common clinical scenarios that are addressed in the 2008 and 2012 national colonoscopy guidelines. After the questions were developed, they were pre-tested and discussed for content and clarity by three experienced gastroenterologists. In addition, demographic and clinical practice data were collected from the respondents using an additional 6 multiple-choice questions. The survey was administered via the Zoomerang website (www.zoomerang.com, Zoomerang, Palo Alto, CA) in November and December 2011. A link to the survey was sent by email to all gastroenterologists in the United States, identified via the American Medical Association database. The survey was sent to a total of 8475 gastroenterologists. The email was sent on our behalf as a single email blast by SDI Health (Plymouth Meeting, PA). No repeat email reminders were sent due to limited funds. All responses were anonymous. While participation was voluntary, an incentive was offered in the form of a raffle for a free iPad2. Completion of the survey was considered implied consent to our study.

Responses were tracked using the survey website and a database of responses was generated for subsequent analysis. Descriptive statistics were used for analysis of demographic data. We analyzed the geographic regions of the United States by dividing it into 4 areas according to the U.S. Census Bureau regions: West, Midwest, Northeast, and South (www.census.gov). A common school grading system was utilized to assess adherence via the number of answers correct on each survey response according to the published 2008 guidelines. An A grade was defined as 90% or greater correct answers, a B grade was defined as 80-89% correct answers, a C grade was defined as 70-79% correct answers, a D grade was defined as 60-69% correct answers, and an F grade (failing grade) was defined as 59% or lower correct answers. Predictors for awareness and adherence with the guidelines were analyzed using a multivariable logistic regression model. The significance of a predictor was indicated by a p-value, and magnitude of effect of a predictor was quantified by odds ratios and 95% confidence intervals. The adequacy of model fit was evaluated by the Hosmer-Lemeshow goodness-of-fit statistic. We used the Cochran-Armitage trend test for to examine possible trends in awareness of guidelines and reporting following guidelines across different categories of colonoscopy volumes. The analyses were performed using SAS statistical software, version 9.3 (SAS Institute Inc, Cary, NC).

RESULTS

The characteristics of the survey respondents are reported in Table 1. A total of 306 gastroenterologists completed the survey yielding a response rate of 3.6% Respondents represented a wide range of years in practice, geographic locations, practice settings, and procedural volumes.

Table 1.

Survey respondent characteristics (n=306 gastroenterologists)^*

Year of finishing training	1990 or earlier 99/303 (32.7%)	1991-2010 160/303 (52.8%)	2011 or later 44/303 (14.5%)
Practice Location	Midwest 70/302 (23.2%)	Northeast 71/302 (23.5%)	South 93/302 (30.8%)	West 68/302 (22.5%)
Practice Setting	Academic 122/304 (40.1%)	Nonacademic 182/304 (59.9%)
Ownership in ambulatory surgical center	Yes 98/304 (32.2%)	No 206/304 (67.8%)
Number of colonoscopies per month	<20 27/306 (8.8%)	20-50 81/306 (26.5%)	50-100 129/306 (42.2%)	>100 69/306 (22.5%)
% reporting awareness of guidelines	Yes 259/306 (84.6%)	No 38/306 (12.4%)	No answer 9/306 (2.9%)
% reporting following Guidelines	Yes 213/306 (69.6%)	No 46/306 (15%)	No answer 47/306 (15.4%)

^*Not all 306 respondents answered all survey questions

Physician Awareness of Guidelines

Among survey respondents, 84.6% reported being aware of the published guidelines. Colonoscopy volume was the only significant predictor for awareness of the guidelines (Table 2). Low-volume endoscopists (< 20 colonoscopies/month) were significantly less likely to be aware of the guidelines (OR 0.26 [95% CI 0.08-0.89], p=0.03) compared to high-volume endoscopists (> 100 colonoscopies/month). Meanwhile, endoscopists who averaged 50-100 colonoscopies/month were significantly more likely than high volume endoscopists (>100 colonoscopies/month) to report awareness of the guidelines (OR 3.03 [95% CI 1.09-8.40], p=0.03).

Table 2.

Gastroenterologist characteristics associated with reporting awareness of guidelines (n=306)

Respondent Characteristic		OR**	95% CI		p-value
Year of completion of training	1991-2010	1	Reference
	2011-present	0.80	0.30	2.15	0.66
	Before 1990	1.44	0.61	3.37	0.40
Region	West	1	Reference
	Midwest	1.39	0.52	3.70	0.52
	Northeast	2.03	0.72	5.68	0.18
	South	1.92	0.71	5.21	0.20
Practice Setting	Nonacademic	1	Reference
	Academic	1.69	0.63	4.55	0.29
Ownership in ambulatory center	No	1	Reference
	Yes	1.79	0.70	4.59	0.22
Number of colonoscopies/month	<20	0.26	0.08	0.89	0.03*
	20-50	0.95	0.34	2.63	0.92
	50-100	3.03	1.09	8.40	0.03*
	>100	1	Reference

^*p<0.05

^**Adjusted OR. Model includes all variables in table.

Physician Report of Following Guidelines

The year fellowship training was completed was the only significant predictor of reporting following guidelines in practice (Table 3). Those who completed training before 1990 were significantly less likely to report following guidelines in their clinical practice (OR 0.37 [95% CI 0.17-0.79], p=0.01). Among physicians aware of the guidelines, 18% reported not following the guidelines. Reasons given for non-adherence with the guidelines are listed in Figure 1. Respondents who had reasons listed as “other” (25%) gave reasons including individualizing colonoscopy intervals to the patient and concerns regarding missed lesions.

Table 3.

Gastroenterologist characteristics associated with reporting following guidelines (n=306)

Respondent Characteristic		OR**	95% CI		p-value
Year of completion of training	1991-2010	1	Reference
	2011-present	0.87	0.27	2.82	0.82
	Before 1990	0.37	0.17	0.79	0.01*
Region	West	1	Reference
	Midwest	0.38	0.12	1.21	0.10
	Northeast	0.47	0.15	1.49	0.20
	South	1.00	0.30	3.26	0.99
Practice Setting	Nonacademic	1	Reference
	Academic	0.77	0.31	1.90	0.57
Ownership in ambulatory center	No	1	Reference
	Yes	0.79	0.33	1.88	0.59
Number of colonoscopies/month	<20	1.14	0.23	5.62	0.87
	20-50	0.86	0.30	2.43	0.77
	50-100	1.02	0.40	2.58	0.97
	>100	1	Reference

^*p<0.05

^**Adjusted OR. Model includes all variables in table.

Figure 1.

Self-reported reasons for not following colonoscopy screening and surveillance guidelines (n=46). Respondents were only given this question if they answered “no” to the question “Do you follow these guidelines in your everyday clinical practice?” They were allowed to select more than one reason

Physician Adherence with Guidelines

The physician responses to clinical scenarios were compared to guideline recommendations. Table 4 summarizes the concepts tested, the results for each question, and the trends of responses. Each completed survey was scored and the percentage of correct answers was calculated based on the guidelines. A school grading system applied to the survey responses based on the percentage of correct answers according to the guidelines is shown in Figure 2. Of the respondents, 16% would have received an A (90% or higher), 15% would have received a B (80-89%), 15% would have received a C (70-79%), 13% would have received a D (60-69%), and 40% would have received a failing grade (59% or lower).

Table 4.

Guidelines tested in survey to assess adherence

Topic	Concept tested	Correct answer	% Correct	%Too early	% Too late
Surveillance Intervals	Detection of small rectal hyperplastic polyps in an average-risk person	10 years	87%	13%	NA
	Detection of 2 small tubular adenomas	5-10 years	41%	59%	NA
	Detection of 3 small tubular adenomas	3 years	70%	3%	27%
	Detection of a tubular adenoma >1 cm	3 years	67%	4%	30%
	Previous personal history of adenomatous polyps on a prior colonoscopy	5 years	79%	18%	3%
	Detection of a tubulovillous adenoma	3 years	59%	4%	37%
	Detection of >10 adenomatous polyps	<3 years (1-2 years)	68%	14%	17%
Family History	Initiating screening if colorectal cancer in a first degree relative was diagnosed younger than age 60	Age 40	53%	10%	37%
	Interval repeat if first degree relative with cancer was younger than age 60	5 years	85%	5%	10%
	Interval repeat if first degree relative with CRC was diagnosed at age 65, and initial screening is normal	10 years	54%	46%	NA
Personal history of CRC	Repeat colonoscopy after curative resection of CRC – if complete colonoscopy was done perioperatively	1 year	88%	5%	7%
	Colonoscopy interval after 2 negative procedures at 1 and 3 years after resection	5 years	74%	24%	2%

Figure 2.

Adherence of U.S. gastroenterologists to colonoscopy guidelines based on percentage of correct responses to clinical scenarios, using a common grading system

The number of correct survey responses was assumed to be a marker of adherence with the guidelines. Compared to physicians who finished training during 1991-2010, less adherence was seen in those who completed training before 1990 (OR 0.75 [95% CI 0.64-0.88], p=0.0005) or were currently in training (OR 0.72 [95% CI 0.58-0.90], p=0.004) (Table 5). Compared to physicians in the Western U.S., less adherence was seen among physicians in the Midwest (OR 0.69 [95% CI 0.55-0.87], p=0.001), Northeast (OR 0.63 [95% CI 0.51-0.79], p<0.001), and South (OR 0.59 [95% CI 0.48-0.73], p<0.001). Non-academic physicians were less adherent compared to academic physicians (OR 0.72 [95% CI 0.59-0.88], p=0.001). Low-volume colonoscopists (<20/month) were less adherent compared to high-volume colonoscopists (>100/month) (OR 0.52 [95% CI 0.39-0.70], p<0.001). This difference was still significant in individuals who performed 20-50 colonoscopies per month as compared to those who performed >100 colonoscopies per month, with those performing fewer colonoscopies being less likely to adhere with the guidelines (OR 0.76 [95%CI 0.61-0.94], p= 0.01). Respondents who performed 50-100 colonoscopies per month, however, were not significantly different from those who performed >100 colonoscopies per month (OR 1.09 [95% CI 0.840-1.235], p=0.85). Hosmer-Lemeshow goodness-of-fit test indicated a good model fit (p=0.79).

Table 5.

Gastroenterologist characteristics associated with adherence with guidelines based on responses to clinical scenarios (n=306)

Respondent Characteristic		OR	95% CI		p-value
Year of completion of training	1991-2010	1	Reference
	2011-present	0.72	0.58	0.90	<0.01*
	Before 1990	0.75	0.64	0.88	<0.001*
Region	West	1	Reference
	Midwest	0.69	0.55	0.87	<0.01*
	Northeast	0.63	0.51	0.79	<0.001*
	South	0.59	0.48	0.73	<0.001*
Practice Setting	Nonacademic	1	Reference
	Academic	1.38	1.13	1.68	<0.01*
Ownership in ambulatory center	No	1	Reference
	Yes	0.93	0.78	1.11	0.43
Number of colonoscopies/month	<20	0.52	0.39	0.69	<0.001*
	20-50	0.76	0.61	0.94	0.01*
	50-100	1.02	0.84	1.24	0.85
	>100	1	Reference

^*p<0.05

** Adjusted OR. Model includes all variables in the table.

DISCUSSION

The survey results highlight that there are deficiencies in adherence to the surveillance guidelines among U.S. gastroenterologists, with approximately 40% answering our survey at a “failing” level if this were a school test. We identified several characteristics that were significantly associated with lower adherence to the guidelines. The first is performing a low volume of colonoscopies. Colonoscopists who performed < 20 colonoscopies or 20-50 colonoscopies per month had a significantly lower adherence than those who performed >100 colonoscopies per month. Meanwhile, gastroenterologists performing 50-100 colonoscopies per month had similar adherence to guidelines with the highest volume gastroenterologists. This suggests that 50 colonoscopies per month may be the minimum threshold of endoscopy volume needed for sufficient practice and recall of these guidelines. In addition, colonoscopists who performed >100 colonoscopies were also significantly more likely than those who performed <20 colonoscopies per month to report being aware of the guidelines.

Finishing training before 1990, or being currently in training both were significantly associated with less adherence with the guidelines. In older graduates, this may indicate a lack of updates in practice or less trust of the evidence-based nature of the guidelines, and substitution of clinical experience. This is in concordance with the self-assessment of this group of physicians, who were significantly less likely to report following the guidelines in their everyday practice. In cases of respondents currently in fellowship, their significantly lower adherence with the guidelines may reflect their current learning curve. Academic physicians had a higher adherence to the guidelines, perhaps due to more opportunities for peer review and education. Although there was no difference among the different geographic regions in physicians reporting awareness of guidelines, when assessed with clinical scenarios, the Western U.S. had significantly higher adherence to guidelines. The significance of these findings from the Western U.S. is unclear, but this may reflect a larger penetrance of managed care in this region, which may dictate when patients are able to receive repeated colonoscopies based on guidelines. A survey of 1423 U.S. colorectal cancer survivors showed that only 49% received a surveillance colonoscopy within 14 months after curative surgery. Similar to our study, there was variation by regions of the U.S. [9] In a study by Goodwin et al, the rates of shorter than indicated screening intervals after an initial negative colonoscopy were mapped and varied greatly by geographic region, with some regions in Texas and Colorado having higher rates than New England, for example.[10] Another study using Medicare claims data which identified that 23.4% of colonoscopies performed were inappropriate also showed large geographic variation.[11] Graduates before 1990 and higher-volume colonoscopists had higher rates of potentially inappropriate colonoscopies in the same claims data study.

This was a national survey with a wide and relatively evenly distributed geographic location of respondents across the regions of the U.S., with most states represented. It represented both academic and non-academic practice, as well as different practice volumes It highlighted the characteristics of physicians who are less likely to adhere to guidelines, which is important for targeting quality improvement and educational efforts in the future. In a prior survey of 116 gastroenterologists preparing for board certification in 2004, only 57% reported that the 2003 guidelines were influential in their practice, and 76% of those who did not follow guidelines opted for shorter intervals because they disagreed with the guidelines.[4] A survey of 192 VA gastroenterologists showed that in many scenarios, respondents had poor knowledge of the guidelines. This study focused on identifying various physician beliefs about the validity, development, and practical application of the guidelines that led to poor adherence. Also brought out were concerns about physician discipline and reimbursement effects of guidelines.[6] In our survey, the reasons provided by physicians for not following recent guidelines can assist in targeting educational efforts for physicians. For example, a reason cited by some was difficulty in recalling the guidelines, which can be addressed by a simple quality improvement measure such as posting the guidelines in the endoscopy room or incorporating reminders in endoscopy documentation software. Sanaka et al performed a study where walletsized cards were distributed to endoscopists, guidelines were posted next to the computers, and guidelines were discussed in monthly meetings in an academic setting. Endoscopy reports were reviewed before and after the intervention to assess the recommended interval and showed an improvement in adherence from 57% to 81%.[12] Educational efforts providing data and evidence to physicians to help them understand the rationale behind the guidelines would also be helpful since 62% of those reporting not following guidelines were concerned that intervals were too long and 17% felt that the guidelines were not based on good evidence (Figure1).

Several studies have documented that physicians are using colonoscopy surveillance intervals that are too long or too short. In 1999 – 2000, a survey assessing adherence of gastroenterologists and surgeons with the 1997 guidelines (only pertaining to hyperplastic polyps and small adenomas) showed that they recommended shorter intervals than suggested by the guidelines at the time.[5] In a Dutch survey, endoscopists recommended shorter post-polypectomy intervals than recommended by the guidelines.[13] A local survey of New Haven gastroenterologists in 2006 focused on average risk patients undergoing screening colonoscopy and the use of fecal occult blood testing (FOBT). Among 54 respondents, 80% accepted a 10 year interval after normal screening colonoscopies in individuals at average risk, and about 50% of respondents recommended interval FOBT testing.[14] In a study of consecutive colonoscopies in 152 physicians and 55 practices in North Carolina, 24% of procedures with only hyperplastic polyps, and 35% of those with small adenomas had shorter-than-guideline intervals recommended.[15] One study focusing on use of surveillance colonoscopy in the community used 3627 participants in the Prostate, Lung, Colorectal and Ovarian cancer screening trial in 9 U.S. communities and showed that there was overuse of surveillance in low risk adenomas, and underuse in higher risk or advanced adenomas.[7] In a prospective cohort of 1237 participants followed for 5.9 years as part of the Polyp Prevention Trial, again there was overuse of surveillance colonoscopy in low risk adenomas, and underuse in high-risk adenomas [8]

A few studies have looked at physician or center characteristics associated with adherence to surveillance guidelines. A survey of 1266 primary care physicians conducted by the National Cancer Institute in 2007 assessed the recommended average-risk screening modalities and showed that only 20% were guideline-consistent. [16] While this survey was different in that it focused on screening only and by primary care physicians, a similarity to our study was that older primary care physicians were less likely to follow the guidelines. However, other factors perhaps unique to the pressures of a primary care practice included that physicians with fewer patients were more likely to follow guidelines, unlike our survey, which showed that gastroenterologists who performed more colonoscopies were more adherent. A study of screening intervals after negative colonoscopy, done by review of Medicare claims data with inclusion of 24,000 colonoscopies, showed that 46.2% had an early colonoscopy in fewer than 7 years, with 42% of those repeated without a clear indication.[10] In this Medicare screening interval study, high-volume colonoscopists or office-based procedures had increased rates of inappropriately short intervals. In an Italian study of 29 endoscopy centers and 902 patients referred for surveillance, only 36.6% had the correct surveillance interval, and 54.3 % had a colonoscopy recommended too early. In Italy, high volume centers, academic centers, those giving written recommendations based on pathology, and colonoscopies in the national screening program were more likely to be compliant with guidelines.[17]

We have shed some light on the inconsistency between perceived knowledge of the guidelines and the application of this knowledge. Most recently, a survey in Canada of 150 members of the Canadian Association of Gastroenterologists that assessed adherence to post-polypectomy guidelines showed again that the intervals recommended were often too short or too long, especially in cases of high-grade dysplasia or villous adenoma.[18] In the Canadian survey, 74% of respondents reported that their recommendations were according to current guidelines. However, a median of 18% who reported practicing these guidelines provided inappropriate surveillance intervals in their survey answers. The VA study also showed higher percentages of self-reported guideline adherence than guideline-concordant responses by the knowledge-based assessment.[6] Quality indicators have recommended that a reason should be documented if surveillance guidelines are not to be followed, but in practice this is rarely done. [19]

Our study is unique in its focus on gastroenterologists, utilization of the most recent guidelines regarding surveillance (published in 2008 and 2012), and in its identification of respondent characteristics associated with adherence to guidelines in the U.S. However, there are several limitations. While we can infer that the self-report responses translated to actual intervals recommended in practice, we cannot be certain. The natural limitation of a survey is that we relied on self-reported data, which may lead to a Hawthorne effect with the knowledge that answers will be assessed. Although we captured geographic regions of the U.S., data was not collected on the rural or urban nature of the practice, which might affect the availability of colonoscopy based on the number of available providers or patient load. It is also possible that respondents were not completely representative of all gastroenterologists, and that a non-response bias exists. While our survey response rate was low, the number of respondents was higher than many previously published studies [4,6,14,15,18]. In addition, our respondents represented a variety of practice settings, geographic locations, and stage of training. However, this is a limitation of all survey-based studies.

While many have noted the disparity between guidelines and practice, our study is the first to identify significant characteristics of gastroenterologists in the U.S. that are predictors of adherence with national guidelines on colorectal cancer screening and surveillance. We recommend targeting future educational efforts in this country to low-volume colonoscopists, physicians who have completed training prior to 1990, and community-based practices. In addition, further study into the optimal interventions for targeting reminders of screening and surveillance intervals should be employed. Attention to these measures will increase the safety of our patients by decreasing interval cancers due to surveillance intervals that are too long, while decreasing costs and risks due to unnecessary procedures when colonoscopy intervals are too short.

Abbreviations

CRC

colorectal cancer

ACS

American Cancer Society

ACR

American College of Radiology

ACG

American College of Gastroenterology

ASGE

American Society for Gastrointestinal Endoscopy