2005 Volume 17 Pages 21-41
Objectives: Once a prostate cancer screening program using prostate-specific antigen (PSA) has been established and is operational, the issue of the re-screening interval for patients with prior negative PSA results comes into question. In Japan, cancer screenings are mainly provided as public services and designing efficient screening programme is important in terms of resource allocation. We approached this issue using a decision-analytic model in which participants were stratified by initial (baseline) PSA values.
Materials and methods: We established a Markov decision analytic model to evaluate the outcomes of prostate cancer screening programs using PSA measurements at various individual rescreening intervals based on baseline PSA levels. Cost-effectiveness analysis was performed to determine the incremental cost-effectiveness ratio (ICER; costs per quality-adjusted life years) for each strategy.
Results: The most cost-effective strategy is the annual screening with respect to biennial screening in men with PSA≤2.0 ng/ml, The strategies expanding biennial screening from this strategy are dominated. ICERs for annual screening and biennial screening strategies in men with PSA≤1.0 were US＄20,827 and US＄3,495, respectively, with respect to strategies with biennial screening in men with PSA≤2.0 ng/ml. On sensitivity analyses, superiority of the annual screening with respect to biennial screening in men with PSA≤2.0 ng/ml is mostly robust. The only exception was that biennial screening in men with PSA≤1.0 ng/ml was the most cost-effective when the cost of PSA check-up was lower than 10.5＄. It was also observed that ICER for an annual screening strategy is larger in an initial age cohort of men in their 50's and 70's than in their 60's. The most important variable in terms of the change in ICER is the PSA cost.
Conclusions: Using a mathematical model, which well expresses outcomes of PSA-based prostate cancer screening programs, an optimal re-screening strategy based on baseline PSA levels can be created according to clinical variables. Annual screenings for all participants can be safely omitted depending on the rate of participation for secondary biopsy, the cancer detection rate on biopsy and the age of participants.
