The appropriateness of more intensive colonoscopy screening than recommended in Medicare beneficiaries: a modeling study

Abstract

Importance: Many Medicare beneficiaries undergo more intensive colonoscopy screening than recommended. Whether this is favorable for beneficiaries and efficient from a societal perspective is uncertain.

Objective: To determine whether more intensive colonoscopy screening than recommended is favorable for Medicare beneficiaries (ie, whether it results in a net health benefit) and whether it is efficient from a societal perspective (ie, whether the net health benefit justifies the additional resources required).

Design, setting, and participants: Microsimulation modeling study of 65-year-old Medicare beneficiaries at average risk for colorectal cancer (CRC) and with an average life expectancy who underwent a screening colonoscopy at 55 years with negative results.

Interventions: Colonoscopy screening as recommended by guidelines (ie, at 65 and 75 years) vs scenarios with a shorter screening interval (5 or 3 instead of 10 years) or in which screening was continued to 85 or 95 years.

Main outcomes and measures: Quality-adjusted life-years (QALYs) gained (measure of net health benefit); additional colonoscopies required per additional QALY gained and additional costs per additional QALY gained (measures of efficiency).

Results: Screening previously screened Medicare beneficiaries more intensively than recommended resulted in only small increases in CRC deaths prevented and life-years gained. In comparison, the increases in colonoscopies performed and colonoscopy-related complications experienced were large. As a result, all scenarios of more intensive screening than recommended resulted in a loss of QALYs, rather than a gain (ie, a net harm). The only exception was shortening the screening interval from 10 to 5 years, which resulted in 0.7 QALYs gained per 1000 beneficiaries. However, this scenario was inefficient because it required no less than 909 additional colonoscopies and an additional $711 000 per additional QALY gained. Results in previously unscreened beneficiaries were slightly less unfavorable, but conclusions were identical.

Conclusions and relevance: Screening Medicare beneficiaries more intensively than recommended is not only inefficient from a societal perspective; often it is also unfavorable for those being screened. This study provides evidence and a clear rationale for clinicians and policy makers to actively discourage this practice.

Figure 1

Model Inputs: Age-Specific Risks for Complications Associated with Colonoscopies with Polypectomy.^{a a}Derived by performing additional statistical analyses on Medicare data used in a study by Warren et al. (eAppendix 2). Only complications requiring hospitalization or an emergency department visit were considered. ^bPerforations, gastrointestinal bleeding or transfusions; risk per colonoscopy = (((EXP(9.27953-0.06105*Age))+1)^-1)-((EXP(10.78719-0.06105*Age))+1)^-1. ^cParalytic ileus, nausea and vomiting, dehydration, abdominal pain; risk per colonoscopy = (((EXP(8.81404-0.05903*Age))+1)^-1)-((EXP(9.61197-0.05903*Age))+1)^-1. ^dMyocardial infarction or angina, arrhythmias, congestive heart failure, cardiac or respiratory arrest, syncope, hypotension, or shock; risk per colonoscopy = (((EXP(9.09053-0.07056*A69))+1)^-1)-((EXP(9.38297-0.07056*A69))+1)^-1.

Figure 2

The Increases in the Benefits (A-D) and the Burden and Harms (E-F) of Screening Associated with More Intensive Colonoscopy Screening than Recommended in Medicare Beneficiaries with a Negative Screening Colonoscopy at Age 55 (numbers per 1,000 beneficiaries; undiscounted). CRC = colorectal cancer; LY = life-year ^aFor each scenario, the distribution of additional LYs with CRC care prevented over the different phases of care and stages of CRC is given in eAppendix 3. ^bOnly complications requiring hospitalization or an emergency department visit were considered.