In this survey of VA practitioners, we described provider recommendations for vignettes on CRC screening in the elderly when faced with patients of different ages, degrees of comorbidity, and prior history of CRC screening, and we explored patient and provider characteristics associated with screening recommendations. We found that VA providers reported being less likely to recommend screening for CRC as patient age increased; this trend was maintained regardless of patient health status as measured by a specific disease state and severity, or life expectancy. Most providers reported they would not screen an elderly patient with a life expectancy of less than 5 years, which is the cutoff below which there is no clear disease-specific survival benefit from CRC screening4–6,10
. This trend was maintained whether the patient had specific advanced disease states (severe CHF or severe COPD) or whether the patient’s life expectancy was less than 5 years irrespective of the degree of comorbidity. However, a substantial minority of respondents (15–21%) reported they would screen a 75 year old with an active extracolonic malignancy, severe CHF, or severe COPD, indicating that age is an important factor in making screening decisions in the elderly, even in the presence of severe comorbidity.
Based on responses to these vignettes, providers appear to assign a cutoff age of 80 depending on the patient’s underlying comorbidity: this was the case for patients with an active extracolonic malignancy or with severe COPD. Conversely, for patients with severe CHF or life expectancy <5 years, most providers reported they were unlikely to recommend CRC screening regardless of patient age. Similar trends were observed when past CRC screening was assessed: younger patients were more likely to be re-screened, and providers appeared to assign a cutoff age of 80 in specific situations, e.g., patients who had a colonoscopy within the previous 5 years. We also found that provider demographic characteristics were not significantly associated with the probability of a screening recommendation. Specifically, there was no association between provider characteristics and the likelihood of “inappropriate screening”: in individuals with short life expectancy (including presence of another active cancer, severe CHF or COPD, and life expectancy stated less than 5 years), and in those who had undergone screening colonoscopy within the preceding 5 years.
To our knowledge, this survey is the first to question providers regarding their practice patterns for screening for CRC in elderly patients in the VA system and to specifically assess the impact of prior screening for CRC in this setting. In a recent study, Lewis et al. surveyed a group of resident physicians at a university internal medicine program, and reported their life expectancy estimates and screening recommendations for hypothetical 75 and 85 year old women patients with good, fair, or poor health states15
. The resident physicians’ life expectancy estimates showed moderate agreement with life table estimates, and their recommendations for CRC screening varied appropriately according to patient life expectancy and health state15
. Cooper et al. surveyed 884 primary care physicians to determine their recommendations for CRC screening using fecal occult blood testing (FOBT) and sigmoidoscopy in four pairs of clinical vignettes that varied by patient age (65 or 75 years) and comorbidity (none, mild, moderate, and severe)14
. Physicians were more likely to recommend screening with FOBT rather than sigmoidoscopy, regardless of patient age and comorbidity. Interestingly, many providers recommended screening with FOBT in inappropriate circumstances, such as a patient with a terminal malignancy14
. Our study complements the aforementioned surveys and advances the field in at least two important ways: First, we surveyed primarily practicing primary care providers (physicians and nurse practitioners) as opposed to physicians-in-training, and this is likely to be more reflective of current screening practices within the VA system. Second, we included past endoscopic screening history in the clinical vignettes, an important factor in screening decision-making that has not been previously assessed and that is especially relevant in a geriatric population. The main strength of this study is its setting; the VA population tends to be older and with higher degrees of comorbidity, and VA providers likely face challenging screening decisions for their elderly patients on a frequent basis. Thus, our findings may be more reflective of actual practice patterns in cancer screening in geriatric age groups than surveys of physicians or residents who do not routinely oversee the care of geriatric patients.
Our study also suggests that inappropriate screening for CRC could occur in the VA system, as evidenced by the substantial minority of providers who would screen patients with an active malignancy, or with severe life-limiting comorbidity. This is also illustrated by the relatively high proportion of providers who would screen patients who had undergone a screening colonoscopy within the preceding 5 years, despite guidelines that recommend a 10-year interval in this setting20
. Recent data show that CRC screening in the VA system is not well targeted to patient comorbidity, with only 47% of patients with no comorbidity and 41% of patients with life expectancies less than 5 years having undergone screening17
. Relatively high rates of screening have also been observed in the case of prostate-specific antigen (PSA) screening in elderly veterans21
. The reasons for “inappropriate” cancer screening in the VA system are unclear, but may be partly driven by performance measures that measure adherence rates to practice guidelines to assess quality of care. As shown by Walter and colleagues22
, these performance measures place pressure on local VAs to score well and thus increase screening rates, but do not properly take into account illness severity, patient preference, or physician judgment. The updated USPSTF guidelines, which recommend against routine screening for CRC in adults 76 to 85 years of age and against CRC screening in adults older than age 85, may ultimately lead to a decrease in CRC screening rates in elderly veterans. However, the impact of these new guidelines on clinical practice is not yet known, and our data collection preceded the publication of the updated guidelines.
Our study has several limitations. First, many of the providers who were surveyed had previously participated in a large survey-based study (CanCORS), and their responses and practice patterns may differ from those of VA practitioners who did not participate. However, there were no significant differences in the demographic and professional characteristics of respondents compared to non-respondents, limiting the impact of selection bias. Second, the sample size was relatively small, despite efforts to ensure a high response rate, and this could have limited our ability to detect meaningful associations between provider characteristics and screening recommendations. Third, response to hypothetical clinical vignettes may not reflect actual clinical practice. On one hand, clinician surveys tend to be hypothetical clinical “snapshots,” which may poorly reflect actual clinical practice, because the vignettes include too few variables to realistically mirror real-life complex medical situations. On the other hand, including too many variables to allow inclusion of all possible clinical scenario permutations would have led to a very large and impractical survey, and generated a large amount of difficult-to-interpret data. Additionally, one of our main aims was to examine the impact of the interaction between patient age and comorbidity on provider screening decisions, and this would have been obscured by the inclusion of additional variables in each vignette. Our work was intended to provide an initial framework for future studies assessing in greater detail variables affecting CRC screening decisions in elderly veterans. Thus, we believe our decision to include two variables in each vignette was a pragmatic, albeit imperfect, compromise. Fourth, we did not assess patient preference as a factor in CRC screening decision-making; in the study by Lewis et al., a significant association was found between physician uncertainty and the recommendation to let the patient make the decision about screening15
. Finally, we did not specify screening modalities when surveying providers about their screening recommendations. In the study by Cooper and colleagues, providers recommended screening with FOBT much more frequently than sigmoidoscopy14
, possibly because FOBT is non-invasive and providers caring for older patients with poor health consider it more appropriate for screening. Indeed, FOBT remains the dominant modality for CRC screening in the VA system23
. However, the effectiveness of screening for CRC depends on proper follow-up of patients with positive FOBT or sigmoidoscopy, and these patients should ideally undergo colonoscopy. This line of reasoning, which considers colonoscopy as the “final common pathway” for all CRC screening, is appropriate when patients are expected to derive a substantial survival benefit from screening that outweighs the risks of colonoscopy, but may not apply to older patients with limited life expectancy.
In conclusion, we found that VA providers incorporate patient age, comorbidity, life expectancy, and past CRC screening history in making decisions when considering CRC screening for elderly veterans, albeit in inconsistent ways with considerable variability. This is consistent with the evidence that clinicians rely on biases and heuristics in decision-making, and these factors (“intuitive” decision making24
) play a larger role as uncertainty increases25
. The impact of the new USPSTF guidelines on CRC screening practices in the VA system is yet to be determined, and it would be interesting to compare our findings with data collected after the publication of the guidelines. Further research with larger sample sizes is needed to address these gaps in evidence, to confirm our findings, and to identify provider characteristics associated with specific screening recommendations.