Comorbidity associated with referral to pulmonary rehabilitation in people hospitalized with chronic obstructive pulmonary disease

PURPOSE: Comorbid conditions are common in people with chronic obstructive pulmonary disease (COPD) and may affect therapeutic management. The aim of this study was to examine the association of comorbidity in people with COPD with referral to a pulmonary rehabilitation (PR) program.

METHODS: An analysis of data was conducted from an observational study of 88 people admitted to hospital with a primary diagnosis of COPD. Demographic and admission-related data were extracted and comorbidity scores (Charlson and Rx-Risk-V) were calculated.

RESULTS: Total comorbidity scores were not associated with referral to PR; however specific comorbid conditions were. The presence of anxiety (from medical records) was more frequent in those referred to PR (Χ² = 4.20; P = .04; OR, 7.0; 95% CI, 0.8-59.0). The presence of hypertension (as determined by Rx-Risk-V) was more likely to result in PR referral (Χ² = 6.69; P = .01; OR, 6.8; 95% CI, 1.6-29.1), and, in those with arrhythmia, PR referral was less likely (Χ² = 4.22; P = .04; OR, 0.28; 95% CI, 0.08-0.99). Patients who had been referred to PR had lower forced expiratory volume in 1 second (FEV₁ percent predicted) (P < .001) and greater hospital bed days in previous 3 years (P = .051). In a multivariate analysis, FEV₁ percent predicted, bed days in the last 3 years, and Rx-Risk-V categories of hypertension and arrhythmia accounted for 25% of variance in referral to PR.

CONCLUSIONS: In addition to COPD disease severity and hospital utilization, specific comorbidities identified with a comprehensive system (ie, the Rx-Risk score) were associated with referral to PR in this sample.