![[ Visit Client Website ]](images/banner.gif)
Background: Guidelines recommend that individuals with a negative screening colonoscopy repeat colonoscopy screening in ten years. However, the impact of this versus other follow-up strategies on health and economic outcomes is uncertain.
Methods: We used a microsimulation model of colorectal cancer (CRC) to evaluate four management strategies starting at age 60 for individuals with a negative colonoscopy at age 50: no further screening; annual immunochemical fecal occult-blood testing (IFOBT); computed tomographic colonography (CTC) every 5y; and colonoscopy (COL) every 10y. Screening and surveillance of individuals with adenomas detected at subsequent screening events were assumed to end at age 80. Outcomes included numbers of colonoscopies, CRC cases and CRC-related deaths; discounted life-years and lifetime costs; and incremental cost-effectiveness ratios (ICERs). As a reimbursement rate for a screening CTC has not yet been set, we performed a sensitivity analysis on CTC cost.
Results: If individuals with a negative colonoscopy at age 50 continue screening with COL-10y, the model predicted 6.4 CRC cases and 2.8 CRC deaths per 1000. Resuming screening at age 60 with CTC-5y was only slightly less effective than COL-10y and reduced the number of additional colonoscopies by nearly half (Table). Compared with no further screening, IFOBT-1y had an ICER of $15,400/LYS; compared with IFOBT-1y, COL-10y had an ICER of $152,400/LYS. At a unit cost of $669, CTC-5y was strongly dominated by COL-10y. If the unit cost of CTC were ≤$342, CTC-5y would have an ICER of ≤$100,000/LYS compared with IFOBT-1y and the ICER for COL-10y compared with CTC-5y would exceed $600,000/LYS.
Conclusions: Continuing screening with colonoscopy every 10y is the most effective strategy for reducing the burden of CRC for individuals who have undergone a negative colonoscopy at age 50. In settings with limited resources and/or limited colonoscopy capacity, resuming screening at age 60 with annual IFOBT is a reasonable approach. If the unit cost of CTC were ≤$342, CTC every 5y would also be advantageous from a cost-effectiveness standpoint.
