Background: Health-related quality-of-life (HRQL) has been poorly studied in large samples of asthmatics from the general population. HRQL and its relationship to asthma-severity were assessed among 900 asthmatics enrolled in the European Community Respiratory Health Survey.
Methods: Among asthmatics, 864 completed the short form-36 (SF-36) questionnaire and 477 also completed the Asthma Quality-of-life Questionnaire (AQLQ). A 4-class asthma-severity scale, combining clinical items, forced expiratory volume in 1 s and the level of treatment and the different asthma-severity components (each of the clinical items and hospitalization) were studied in relation to HRQL.
Results: Mean SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS) scores (45.5 and 48.8 respectively) were lower than expected in a general population. The mean total AQLQ score was 5.8. The AQLQ score and to a lesser extent the PCS score were significantly related to the 4-class asthma-severity scale, although the risk of having a lower HRQL score did not vary proportionally across the levels of severity. Asthma-severity had no impact on the MCS score. Asthma attack frequency and hospitalization were associated with both total AQLQ and PCS scores, whereas nocturnal symptoms and lung function were more strongly related to the AQLQ and PCS score respectively.
Conclusion: In population-based asthmatics, the specific AQLQ questionnaire, and also to a lesser extent the generic SF-36 questionnaire, were sensitive to asthma-severity. Frequencies of asthma attacks, of nocturnal symptoms and hospitalization for asthma have independent impact on HRQL.