Study objectives: Assess cost effectiveness for providing alpha(1)-antitrypsin (alpha(1)-AT) replacement therapy to individuals with severe COPD and alpha(1)-AT deficiency.
Materials and methods: The electronic databases MEDLINE and EMBASE were searched, and relevant bibliographies were reviewed. Effect size, defined as the absolute risk difference between treated and untreated groups, was taken from the highest level of supporting evidence. The cost for providing alpha(1)-AT replacement therapy was analyzed from a payer perspective and was based on Medicare reimbursement rates. Effect size and costs were varied. The year of life saved was discounted up to 7%.
Results: The incremental cost per year of life saved for alpha(1)-AT replacement therapy (60 mg/kg/wk IV) in a 70-kg subject with severe alpha(1)-AT deficiency and an FEV(1) < 50% of predicted based on the National Institutes of Health (NIH) Registry mortality rate data is $13,971. The incremental cost depends substantially on the mortality rate reduction. When the effect size is altered from 10 to 70%, with the cost fixed at $52,000, the incremental cost per year of life saved ranges from $152,941 to $7,330. When effect size is 55% (as in the NIH Registry) but costs are increased almost 300%, from $52,000 to $150,000 per year, then the incremental cost per year of life saved increases from $13,971 to $40,301.
Conclusion: No randomized, placebo-controlled trials are available to assess mortality rate reduction with alpha(1)-AT replacement therapy. The best currently available data are observational, from the NIH Registry. Based on these data, alpha(1)-AT replacement therapy is cost-effective in individuals who have severe alpha(1)-AT deficiency and severe COPD.