Study objective: Measures of health-related quality of life (HRQL) correlate with disease stage in persons with COPD. However, as their predictive capacity for mortality or medical utilization is less well defined, we sought to examine the relationship of a general measure of HRQL and outcomes in persons with obstructive lung disease.
Design: Prospective cohort study.
Setting: Upper Midwest Veterans Integrated Service Network (VISN)-13.
Participants: All veterans in VISN-13 (n = 70,017) were surveyed with the Veterans Short Form 36 (SF-36V). Persons with reported asthma or COPD who completed the SF-36V formed the study cohort (n = 8,354).
Measurements and results: For purposes of analysis, individuals were divided into quartiles of HRQL according to their physical component summary (PCS) and mental component summary (MCS), values derived from the SF-36V. Outcomes of mortality, hospitalization, and outpatient visits were recorded for 12 months after the survey. Outpatient utilization was dichotomized into high vs low use, with high use being defined as the upper quartile of visits in the 12 months prior to survey mailing. The study cohort had a mean age of 65 years and was largely male (95%), both consistent with a veteran population. After correcting for potential confounding factors through multivariable regression, the PCS was independently predictive of death, hospitalization, and high outpatient utilization. When using the first quartile of PCS as the reference population, those in the fourth quartile of PCS had a hazard ratio for death of 5.47 (95% confidence interval [CI], 3.63 to 8.26). Similarly, the odds ratios for hospitalization, high primary care visits, and high specialty medicine visits in the fourth quartile of PCS were 1.82 (95% CI, 1.51 to 2.19), 1.54 (95% CI, 1.26 to 1.87), and 1.46 (95% CI, 1.21 to 1.78), respectively. The MCS, through multivariable regression, was predictive of death but unassociated with subsequent hospitalization or high outpatient utilization.
Conclusion: HRQL, as assessed by the SF-36V, is an independent predictor of mortality, hospitalization, and outpatient utilization in persons with self-reported obstructive lung disease.