Alpha1-antitrypsin (AAT) deficiency is a common genetic disorder with prevalence similar to that of cystic fibrosis. Chronic augmentation therapy with alpha1-proteinase inhibitor (A1-PI) slows the progression of emphysema. We compared selected clinical outcomes in patients with AAT deficiency and emphysema who had received A1-PI augmentation versus those who had not.
Using a large health-care claims database (∼12M covered lives), we identified all patients with one or more claims with an ICD-9-CM diagnosis code for AAT deficiency and one or more claims with a diagnosis code for emphysema during calendar year (CY) 2002. We then stratified patients according to whether or not they received A1-PI therapy during CY2002, and compared selected clinical measures between these groups.
A total of 771 patients were identified in CY2002 with AAT deficiency, of whom 197 also had emphysema. Only 116 (59% of all patients with AAT deficiency and emphysema) received A1-PI augmentation therapy. Patients who had received A1-PI augmentation did not differ with respect to age, sex, or the prevalence of other respiratory diseases from those who had not. A1-PI augmented patients were more likely to have received bronchodilators (91% vs 64%; p<0.01), supplemental oxygen (19% vs 4%; p<0.01), and inhaled corticosteroids (69% vs 44%; p<0.01); they were less likely to have received outpatient intravenous antibiotics (2% vs 14% respectively; p<0.01), and had fewer hospitalizations per patient (0.3 vs 0.8; p<0.01).
Substantial number of patients with emphysema secondary to AAT deficiency may not be receiving A1-PI augmentation therapy. Augmentation therapy with A1-PI may positively impact clinical outcomes, as evidenced by lower rates of hospitalizations and outpatient intravenous antibiotic use.
Adherence to ATS/ERS standards (i.e., diagnosis and augmentation with A1-PI) may improve health outcomes and reduce utilization of costly health-care services.
K.C. Chung, Study funded by Baxter BioScience