Cost-effectiveness of prenatal screening for postpartum thyroiditis

Five percent of all pregnant women and 25% of pregnant women with insulin-dependent diabetes mellitus (IDDM) develop postpartum thyroiditis (PPT) during the first year after delivery. PPT has significant morbidity and can be predicted prenatally by the presence of thyroid peroxidase (TPO) antibody. Our objective was to estimate the cost-effectiveness of screening pregnant women for the TPO antibody versus the current strategy of no screening test or an alternative strategy of a thyroid-stimulating hormone (TSH) test 6 weeks postpartum. We performed cost-effectiveness analysis using a decision tree model that accounted for cases of PPT detected, medical outcomes of screening, and costs of screening and care. Hypothetical cohorts of 1000 pregnant women with uncomplicated pregnancies and 1000 pregnant women with IDDM were used to determine direct medical costs, quality-adjusted life years, and cases of PPT detected. The cost of testing 1000 pregnant women for TSH at the 6 week postpartum visit was $75,000, with an effectiveness of 995.2 quality-adjusted life years resulting in a cost-effectiveness ratio of $48,000 per quality-adjusted life year. Checking a TPO antibody was more effective (995.5 quality-adjusted life years) but also more expensive ($93,000). The incremental cost-effectiveness ratio of the TPO antibody strategy was $60,000 per quality-adjusted life year. Results were most sensitive to changes in the test characteristics, incidence of disease, and percentage of women with PPT who were symptomatic. A separate analysis for women with IDDM resulted in an incremental cost-effectiveness ratio of $13,000 per quality-adjusted life year for the TSH strategy and $32,000 per quality-adjusted life year for the TPO strategy. Screening for PPT is likely to be reasonably cost-effective and should be considered for inclusion as part of routine pregnancy care.