Abstract:
Purpose To further our understanding of the relationships between asthma control and health-related quality of life (HRQOL) and provide insights into the relative usefulness of various measures in different research contexts. We present a conceptual model and test it with longitudinal survey data. Methods Participants recruited via population sampling and hospital Emergency Departments completed questionnaires every 6 months for up to 3 years. Measures included: sleep disturbance, use of short-acting beta agonists (SABA), activity limitation, urgent medical visits, hospital use, Marks¿ Asthma Quality of Life Questionnaire (AQLQ-M) and the SF-36 Health Survey. Correlation analysis and multi-level models tested predictions from the conceptual model. Results A total of 213 people with asthma aged 16¿75 years provided 967 observations. Correlations between asthma control and asthma-specific HRQOL were stronger than those between asthma control and generic HRQOL. The asthma control variables explained 54¿58% of the variance in asthma-specific HRQOL and 8¿25% of the variance in generic HRQOL. Activity limitation was the main contributor to between-person variation, while sleep disturbance and SABA use were the main contributors to within-person variation. Conclusions Sleep disturbance and SABA use may be most useful in evaluating treatment effectiveness, while activity limitation may be better when monitoring the impact of asthma in populations.
