Cost-effectiveness of 3 methods to enhance the sensitivity of Papanicolaou testing

Abstract

Context ThinPrep, AutoPap, and Papnet are 3 new technologies that increase the sensitivity and cost of cervical cancer screening.

Objective To estimate the cost-effectiveness of these technological enhancements to Papanicolaou (Pap) tests.

Design We estimated the increase in sensitivity from using these technologies by combining results of 8 studies meeting defined criteria. We used published literature and additional sources for cost estimates. To estimate overall cost-effectiveness, we applied a 9-state time-varying transition state model to these data and information about specific populations.

Setting A hypothetical program serving a cohort of 20- to 65-year-old women who begin screening at the same age and are representative of the US population.

Results The new technologies increased life expectancy by 5 hours to 1.6 days, varying with the technology and the frequency of screening. All 3 technologies also increased the cost per woman screened by $30 to $257 (1996 US dollars). AutoPap dominated ThinPrep in the base case. At each screening interval, AutoPap increased survival at the lowest cost. The cost per year of life saved rose from $7777 with quadrennial screening to $166,000 with annual screening. Papnet produced more life-years at a higher cost per year of life saved. However, when used with triennial screening, each of them produced more life-years at lower cost than conventional Pap testing every 2 years. The cost-effectiveness ratio of each technology improved with increases in the prevalence of disease, decreases in the sensitivity of conventional Pap testing, and increases in the improvement in sensitivity produced by the technology.

Conclusions Technologies to increase the sensitivity of Pap testing are more cost-effective when incorporated into infrequent screening. Increases in sensitivity and decreases in cost may eventually make each technology more cost-effective.

Screening with the Papanicolaou (Pap) test is widely regarded as a cost-effective but imperfect approach to the prevention of cervical cancer. New technologies improve the sensitivity (true-positive rate or TPR) of Pap testing. The AutoPap 300 QC (NeoPath Inc, Redmond, Wash) and Papnet (Neuromedical Systems Inc, Suffern, NY) systems combine automated microscopy and computerized analysis to reduce screening error—the failure to identify abnormalities on the slide—by detecting abnormal cells overlooked on initial examination. The ThinPrep 2000 (Cytyc-Sands, Boxborough, Mass) is a semiautomated, liquid-based slide preparation system. It filters noncellular material before depositing cells in a thin layer on the slide. ThinPrep may reduce screening error as well as sampling error, the failure to obtain a representative sample of cells on the slide. All 3 technologies increase the incremental cost per slide screened. We explore the role for these technologies by assessing their cost-effectiveness (CE) in the prevention of cervical cancer morbidity and mortality.