PURPOSE: To assess gender-based differences in hospitalization rates for chronic obstructive pulmonary disease (COPD) among participants in a disease management program.
METHODS: This study used an administrative claims database from a Northeastern health plan supplemented with disease management program (DMP) information to identify factors associated with COPD hospitalizations for participants followed for up to 3.5 years. Patients referred into the DMP were included in the analyses if they had a valid spirometry test within two years of enrollment in the DMP. Severity of COPD was assessed according to FEV1 percent predicted (mild/moderate ≥50%; severe 30%≥FEV1<50%; very severe <30%). Poisson regression was used to assess factors associated with COPD hospitalizations.
RESULTS: A total of 268 patients met selection criteria. Their average age was 71 years, and 57% were female. The overall unadjusted rate of COPD hospitalizations was 3.1 per 100 person-months. Unadjusted monthly rates of COPD hospitalizations were numerically higher for female versus male patients with severe and very severe COPD (see Table). Multivariate analyses revealed that the strongest predictors (p < 0.05) of COPD hospitalizations were severe and very severe COPD, independent homemaking status, higher comorbidity, 1+ COPD exacerbations in the prior six months, and the interaction of female gender with severe and very severe COPD. Adjusted monthly rates of exacerbations were significantly higher (p < 0.05) for female versus male patients with severe COPD (5.70 and 2.76 per 100 person-months, respectively) and very severe COPD (3.55 and 2.36 per 100 person-months, respectively).
CONCLUSION: Females with severe and very severe COPD enrolled in a DMP experienced more hospitalizations for COPD than their male counterparts.
CLINICAL IMPLICATIONS: While disease severity and comorbidity might be expected to influence hospitalization rates for COPD, our finding of gender differences merits further investigation.
DISCLOSURE: L. Boulanger, University grant monies; Grant monies (from industry related sources) Research support received from Pfizer Inc.