Setting the target for a better cervical screening test: Characteristics of a cost-effective test for cervical neoplasia screening

Objective: To determine the potential effects on costs and outcomes of chan ges in sensitivity and specificity with new screening methods for cervical cancer. Methods: Using a Markov model of the natural history of cervical cancer, we estimated the effects of sensitivity, specificity, and screening frequency on cost-effectiveness. Our estimates of conventional Papanicolaou test sen sitivity of 51% and specificity of 97% were obtained from a metaanalysis. W e estimated the effect of reducing raise-negative rates from 40-90% and inc reasing false-positive rates by up to 20%, independently and jointly. We Va ried the marginal cost of improving sensitivity from $0 to $15. Results: When specificity was held constant, increasing sensitivity of the Papanicolaou test increased life expectancy and costs. When sensitivity was held constant, decreasing specificity of the Papanicolaou test increased c osts, an effect that was more dramatic at more frequent intervals. Decrease d specificity had a substantial effect on cost-effectiveness estimates of i mproved Papanicolaou test sensitivity. Most of those effects are related to the cost of evaluation and treatment of low-grade lesions. Conclusion: Policies or technologies that increased sensitivity of cervical cytologic screening increased overall costs, even if the cost of the techn ology was identical to that of conventional Papanicolaou smears. These effe cts appear to be caused by relatively high prevalence of low-grade lesions and are magnified at frequent screening intervals. Efficient cervical cance r screening requires methods with greater ability to detect lesions that ar e most likely to become cancerous. (Obstet Gynecol 2000;96:645-52. (C) 2000 by The American College of Obstetricians and Gynecologists).