Health care utilization in chronic obstructive pulmonary disease - A case-control study in a health maintenance organization

Background: Information about health care utilization and costs among patie nts with chronic obstructive pulmonary disease (COPD) is needed to improve care and for appropriate allocation of resources for patients with COPD (CO PD patients or cases) in managed care organizations. Methods: Analysis of all inpatient, outpatient, and pharmacy utilization of 1522 COPD patients continuously enrolled during 1997 in a 172484-member he alth maintenance organization. Each COPD case was matched with 3 controls ( n=4566) by age (+/-5 years) and sex. Information on tobacco use acid comorb idities was obtained by chart review of 200 patients from each group. Results: Patients with COPD were 2.3 times more likely to be admitted to th e hospital at least once during the year, and those admitted had longer ave rage lengths of stay (4.7 vs 3.9 days; P<.001). Mean costs per case and con trol were $5093 vs $2026 for inpatient services, $5042 vs $3050 for outpati ent services, and $1545 vs $739 for outpatient pharmacy services, respectiv ely (P<.001 for all differences). Patients with COPD had a longer smoking h istory (49.5 vs 34.9 pack-years; P=.002) acid a higher prevalence of smokin g-related comorbid conditions and were more likely to use cigarettes during the study period (46.0% vs 13.5%; P<.001). Conclusions: Health care utilization among COPD patients is approximately t wice that of age- and sex-matched controls, with much of the difference att ributable to smoking-related diseases. In this health maintenance organizat ion, inpatient costs were similar to and outpatient costs were much higher than national averages for COPD patients covered by Medicare.