Strategies to Improve Follow-up After Positive Fecal Immunochemical Tests in a Community-Based Setting: A Mixed-Methods Study

Stool testing for occult blood to screen for colorectal cancer (CRC) has been shown to reduce CRC incidence and mortality (1). The fecal immunochemical test (FIT) has largely replaced guaiac-based fecal screening because of improved sensitivity of FIT screening for CRC and advanced adenomas, specificity for human hemoglobin, and acceptance by screening participants (2). Although colonoscopy remains the dominant CRC screening test in the United States (3), FITs are increasingly recognized as an important component of CRC screening programs, given that they are noninvasive, can be mailed through outreach and completed at home, and can increase overall screening rates (4,5). FIT-based screening is a 2-step process that requires timely colonoscopy follow-up after a positive test. European and Canadian guidelines recommend follow-up within 30 and 60 days, respectively (6,7), and delays of longer than 6 months are associated with an increased risk of any CRC and advanced CRC (8). Although rates of colonoscopy follow-up in landmark randomized trials were 80% to 90% (9), multiple screening programs have reported that as few as 50% of test-positive screening participants get appropriate follow-up (10–13). Follow-up is challenging in that it requires referral from primary care to gastroenterology, evaluation of patient suitability, explaining the need for an invasive diagnostic test, following complex bowel preparation instructions, and undergoing the invasive procedure itself (14). In addition, participants may misunderstand recommendations, fail to perceive themselves as at increased cancer risk, or be reluctant to undergo an invasive procedure (15). Organized screening programs in Europe usually mail results to both referring physicians and participants, sometimes augmented by personalized telephone calls (16) or default follow-up appointments (17). They typically have higher rates of colonoscopy follow-up than those seen in the United States. A recent systematic review found moderate evidence to support patient navigators and provider reminder systems to improve follow-up, but scant evidence about useful system-level strategies (18). Some studies have suggested that strategies such as automated referral to gastroenterology, electronic registries to track patients, and quality improvement efforts can provide modest improvements, but these studies had significant potential biases (19–21). Given that participant-, provider-, and system-level factors can all contribute to lack of follow-up (22), sustained strategies at multiple levels may be beneficial. In 2006, Kaiser Permanente Northern California (KPNC) shifted from opportunistic CRC screening (primarily sigmoidoscopy) to an organized annual FIT-based mailed outreach screening program for all screening eligible members complemented by opportunistic screening colonoscopy (by request). This led to substantial improvements in the percentage of eligible adults up to date with screening, reaching >80% (23–25). In the current study, we sought to identify and describe the stepwise implementation of numerous system-level strategies to improve timely colonoscopy follow-up of positive FITs between 2006 and 2016. We then evaluated changes in time to colonoscopy over 3 periods across the 10-year study interval. Finally, for 2016, we compared colonoscopy completion rates and implementation of strategies between service areas.