Health-related quality of life and future health care utilization for asthma

Background Although health-related quality of life (HRQL) has been increasingly used as an outcome in asthma, its utility for identifying patients at risk for adverse asthma outcomes has not been established. Objective In a prospective cohort study, to evaluate the longitudinal impact of HRQL on future health care utilization and cost among adults with asthma, accounting for known risk factors for utilization. Methods A stratified random sample of 3,482 adult Northern CA Kaiser Permanente members with asthma was selected using computerized utilization databases and a screening survey item. Subjects completed a mail survey that included measures of generic (SF-12) and asthma-specific HRQL (ITG-Asthma Short Form battery). During the 12 months after survey completion, computerized utilization and cost data were ascertained. Results Better baseline asthma-specific HRQL was associated with a decreased risk of asthma-related emergency department visit or hospitalization during longitudinal followup (odds ratio per 10-point score increment 0.84; 95% confidence interval [CI] 0.74 to 0.95), controlling for demographic and clinical factors. Better baseline generic physical HRQL was associated with a decreased risk of future all-cause hospitalization (odds ratio 0.68; 95% CI 0.60 to 0.77). More favorable asthma-specific HRQL scores were also related to decreased asthma-related health care costs during the ensuing year (−0.086 log-dollars per 10-point score increment; 95% CI −0.11 to −0.06). Better generic physical HRQL scores were associated with lower total costs (−0.24 log-dollars; 95% CI −0.32 to −0.17). Conclusions In a large cohort of adult health maintenance organization members with asthma, asthma-specific HRQL was associated with future asthma-related utilization and cost.