S239 Adherence to Colorectal Cancer Screening and Associated Healthcare Resource Utilization, a Longitudinal Analysis in US Medicare Population with Ten Years Follow-up

Abstract

Introduction: Adherence to screening guidelines is critical for prevention and early detection of colorectal cancer (CRC). This study examined CRC screening adherence in Medicare beneficiaries and associated long-term healthcare resource utilization (HCRU) and Medicare costs. Methods: Using 20% Medicare random sample data, the study population included Medicare fee-for-service beneficiaries aged 66-75 years on 1/1/2009, at average-risk for CRC (no history of CRC, polyps, inflammatory bowel disease, or hereditary CRC syndrome), and continuously enrolled in Medicare part A/B from 2008 through 2018. The baseline year (2008) was used to define comorbidities and high-risk events. We excluded those who had a colonoscopy or flexible sigmoidoscopy (flex sig) during 2007-2008 and assumed everyone was due for screening in 2009; screening patterns were determined in the 10-year period, 2009-2018. Subjects were categorized as “adherent to screening” based on the USPSTF guidelines: colonoscopy every 10 years, flex sig every 5 years, multi-target stool DNA test every 3 years, or at least 8 fecal immunochemical or guaiac-based fecal occult blood tests in the 10-year period. Subjects were categorized as “not screened” if there were no tests observed; and “inadequately screened” if testing occurred but not enough to qualify as adherent. The long-term HCRU and inflation adjusted Medicare costs in the 10 years were calculated as mean per patient per year (PPPY). Results: In total, 895,846 eligible individuals were in the final sample. Of these, 13.2% were adherent to screening, 53.4% were inadequately screened, and 33.4% were not screened. Differences in baseline characteristics are presented in Table 1. Compared to those not screened, adherent or inadequately screened individuals were more likely to be female, of white race, and have comorbidities (Table 1). These individuals also used more healthcare services and therefore had higher Medicare costs (Figure 1). For example, physician visits were 14.6, 22.9, and 25.9 PPPY; total Medicare costs were $6,102, $8,469, and $9,102 PPPY for those not screened, inadequately screened, and adherent to screening, respectively. Conclusion: In Medicare beneficiaries at average-risk, adherence rate to CRC screening was low although the rate might be underestimated due to lack of early Medicare data. The link between HCRU and screened status suggests that screening initiatives not dependent on clinical visits may be needed to reach those who are unscreened or inadequately screened.Figure 1.: (a) Healthcare resource utilization measured as number of IP admissions, number of IP stay in days, or number of visits per patient per year (PPPY). (b) Mean Medicare cost measured as Medicare paid amount in 2018 US $PPPY. IP, inpatient; OP, outpatient; ED, emergency department; SNF, skilled nursing facility; HH, home health; DME, durable medical equipment; Part D, Medicare prescription drug.Table 1.: Table.Patient characteristic distribution by CRC screening patterns and odds ratio of adherence to or inadequately screened