Cost-effectiveness of population screening for alpha-1 antitrypsin deficiency: a decision analysis

The objective was to assess the cost-effectiveness of population screening for alpha-1 antitrypsin (AAT) deficiency. The design was a Markov-based decision analytic model. Hypothetical cohorts were analyzed from birth and followed over time until death using Monte Carlo simulation. The following strategies were compared: 1) screen all newborns, 2) screen all 10-year-old children, and 3) do not screen. Screenees found to have PI*ZZ AAT deficiency received the benefits of lower smoking rates and were offered augmentation therapy. In keeping with reported experience, most (96%) non-screened AAT deficient individuals remained undiagnosed and, therefore, missed these benefits. Under base conditions, screening all newborns cost nearly $422,000 per quality-adjusted life-year (QALY) gained; this estimate fell to $92,135 per QALY when the cost of screening was minimized to $6 in the model. Delaying screening until age 10 decreased the incremental cost-effectiveness ratio (ICER) to nearly $317,000. In sensitivity analysis, when the prevalence of PI*ZZ individuals increased from a baseline of 1.96 to 16 per 10,000, the ICER for newborn screening decreased below $100,000 per QALY. When the cost of screening and augmentation therapy were decreased simultaneously with increasing PI*ZZ prevalence, there were many scenarios in which the ICER decreased below $50,000. While population-based screening for AAT deficiency is not cost-effective under current conditions, cost-effectiveness criteria could be satisfied when case-finding in a high prevalence population is undertaken.