We examined the feasibility of a randomized clinical trial of intravenous augmentation therapy for individuals with alpha 1-antitrypsin (α1AT) deficiency, basing calculations on newly available data obtained from the NHLBI Registry of Patients with Severe Deficiency of Alpha 1-Antitrypsin. Using rate of FEV1 decline as the primary outcome and adjusting for noncompliance, a study of subjects with Stage II chronic obstructive pulmonary disease (COPD) (initial FEV1 35 to 49% predicted) with biannual spirometry measures obtained over 4 yr of follow-up would require 147 subjects per treatment arm to detect a difference in FEV1 decline of 23 ml/yr (i.e., a 28% reduction), the difference observed in the NHLBI Registry (1-sided test, α = 0.05, 90% power). To detect a 40% reduction in mortality in a 5-year study of subjects with baseline FEV1 35 to 49% predicted, recruited over the first 2 yr and then followed an additional 3 yr, 342 subjects per treatment arm would be needed. Though significant impediments to carrying out a clinical trial exist, including the cost of such a trial and the potential difficulties in recruiting patients for a placebo-controlled trial, we recommend a randomized controlled trial as the best method to evaluate the efficacy of intravenous augmentation therapy and of possible future treatments.
|Number of pages||6|
|Journal||American Journal of Respiratory and Critical Care Medicine|
|Issue number||3 I|
|Publication status||Published - 6 Apr 2000|
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Critical Care and Intensive Care Medicine