PAR3: THE STANDARDIZED ASTHMA-RELATED QUALITY OF LIFE QUESTIONNAIRE (AQLQ-S): DOES SOCIOECONOMIC STATUS EFFECT MEASUREMENTS?

Abstract

OBJECTIVE: The objective of this analysis was to evaluate the impact of social class on correlation between the standardized AQLQ, self-rated asthma severity and control, and patient utility. METHODS: 84 asthmatic subjects completed the AQLQ. Self-rated asthma severity and control was measured on a 5-point Likert scale and utilities were measured using a rating scale. SES was defined based on receipt of social assistance. Correlations between AQLQ scores and each other variable were measured using Spearman's Rank correlation coefficient (rS). Differences in rs between social classes (rsdiff) were analyzed using Fisher's r to z transformation (2-tailed). RESULTS: 38 (45%) patients were receiving social assistance. In the entire sample, there was significant correlation (p < 0.05) between all AQLQ scores (symptoms, activity, emotion, environment, and global), self-rated asthma severity (rS = 0.21–0.38), control (rS = 0.21–0.38), and utilities. Symptom, activity, and global AQLQ scores were correlated strongly with utility (rS = 0.53–0.54; p < 0.0001) and moderately with environment and emotion scores (rS = 0.38;p = 0.002). However, AQLQ scores were consistently more strongly correlated with self-assessed severity and control in lower SES patients. Although rS diff ranged from 0.07 to 0.55 (mean = 0.27), only the most extreme difference was significant (activity score and control − rS diff = 0.55; p = 0.01). Conversely, rS between all AQLQ scores and utility were consistently lower (mean rS diff = 0.18; range 0.9–0.23) in patients on social assistance, although not significantly. CONCLUSIONS: Correlations between AQLQ scores and utility were consistently lower in lower SES subjects, suggesting that AQLQ may be a better measure of overall health in higher SES patients. Conversely, AQLQ scores correlated more strongly with self-rated asthma severity and control in lower SES subjects. Although most differences were not significant despite their magnitude, this is likely due to a recognized lack of power of the Fisher's r to z transformation test.