Background: Although health-related quality of life (HRQL) in asthma is strongly influenced by disease severity, demographic and socioeconomic variables may also be important factors.
Objective: We related demographics, asthma severity, and socioeconomic factors to HRQL.
Methods: We interviewed 50 patients with moderate or severe asthma recruited from outpatient health center-based clinics to determine demographics, socioeconomic status, asthma severity, medication use, and HRQL. For HRQL, the mean total score of the Asthma Quality of Life Questionnaire (AQLQ) and the Medical Outcomes Study Short-Form 36 questionnaires physical and mental component summary scores (PCS and MCS, respectively) were used.
Results: The mean patient age was 46 +/- 14 years, and the FEV1 was 75% +/- 21% of predicted value. Twenty-nine subjects had been hospitalized for asthma, 29 belonged to a minority racial/ethnic group, and 16 had less than 12 years of education. The mean total AQLQ score was 4.12 +/- 1.42, the PCS was 37 +/- 10, and the MCS was 45 +/- 13. In univariate analyses, severity (nighttime awakenings, prednisone use, and a history of emergency department visits), racial/ethnic group (African American, white, or Hispanic), and socioeconomic status (low educational level, unemployed, family income under $20,000, public assistance, or no health insurance) were related to HRQL. These factors explained 67% of the variance of AQLQ and 48% of the variance of the PCS. Much of the quality of life variance was shared among these variables. Explanatory variables were not related to MCS in multivariate analysis.
Conclusion: Socioeconomic status is an additional important independent factor influencing HRQL in asthma. In this study it was difficult to separate out the unique effects of socioeconomic status and race/ethnicity.