Background: We investigated a large population of patients with chronic obstructive pulmonary
disease (COPD) to determine their frequency of medication use and patterns of
pharmacotherapy.
Methods: Medical and pharmacy claims data were retrospectively analyzed from 19 health plans
(.7.79 million members) across the US. Eligible patients were aged $40 years, continuously
enrolled during July 2004 to June 2005, and had at least one inpatient or at least two outpatient
claims coded for COPD. As a surrogate for severity of illness, COPD patients were stratified
by complexity of illness using predefined International Classification of Diseases, Ninth Revision,
Clinical Modification, Current Procedural Terminology, Fourth Edition, and Healthcare
Common Procedure Coding System codes