Efficacy and cost-effectiveness of nationwide cervical cancer screening in Taiwan.

The annual cervical screening programme using the Papanicolaou (Pap) smear test was launched for women aged 30 years and over from 1995 in Taiwan. This study aimed to evaluate the Taiwanese cervical screening policy and to make recommendations based on the empirical findings from cervical screening data between 1995 and 1998. We used a stochastic process to model the natural history of precancerous lesions and cervical cancer. Based on the estimated results, Monte-Carlo computer simulation was used to evaluate the effectiveness in terms of the reduction in incidence of and mortality from cervical cancer for screening regimes with different screening intervals. Annual Pap smear screening with 100% compliance was estimated to lead to an approximate 80% reduction in deaths from cervical cancer. With 50% compliance, around a 40% reduction was expected. Triennial screening with high compliance was as effective as annual screening with low compliance, and more cost-effective. Based on the observed Taiwan Pap smear-screening programme between 1995 and 1998, with 44.5% women attending at least once, there was an estimated reduction of 16% in deaths from cervical carcinoma. The estimated effectiveness was greater when the period was extended to 2001, in which period 61% of women attended at least once. The screening programme by 2001 was estimated to reduce cervical cancer mortality by 50% (95% confidence interval: 29-65%). The incremental cost-effectiveness was estimated as 8174 dollars per additional life-year gained. In conclusion, triennial screening targeting women aged 30-69 is recommended, along with efforts to enhance the compliance rate.