Aim: To test the discriminative metric properties and specificity of the Serbian version of the Asthma Quality of Life Questionnaire (AQLQ) for assessment of the quality of life in asthma patients.
Method: We studied 100 atopic and 60 nonatopic adult asthma patients with different disease severity, who were consecutively recruited from the outpatient and inpatient departments of the Institute of Allergology and Immunology, University Center of Serbia, between March 2000 and June 2002. After linguistic validation, AQLQ was administered, as well as Paykel's scale of stressful life events. Tests of statistical significance and General Linear Model were used to explore the correlation between characteristics of patients, disease, and environment, and AQLQ scores. Reliability of the questionnaire was evaluated by determining its internal consistency with Cronbach's alpha coefficient.
Results: A more severe form of the disease (F=16.05; p<0.001), life in rural areas (t=-2.67; p=0.008) and changes in weather conditions (t=3.05; p=0.003) were significantly associated with worse overall quality of life of the tested asthma patients. Older patients had poorer quality of life in domains of activity limitation (B=-0.024; 95% confidence interval [CI], -0.036 to -0.011; p<0.001) and exposure to environmental stimuli (B=-0.022; 95% CI, -0.039 to -0.006; p=0.008). Higher values of forced expiratory volume in one second (FEV1, % predicted) were correlated with better quality of life in overall (B=0.017; 95% CI, 0.009-0.025; p<0.001) and other questionnaire domains, except in domain of environmental stimuli. Poorer overall quality of life was recorded in atopic patients sensitive to house dust mites (t=2,60; p=0.011). Form (atopic and nonatopic) and duration of disease, as well as stressful life events were not significantly related to asthmatic patients' quality of life. The Cronbach's alpha ranged from 0.72 to 0.93.
Conclusion: Disease severity, place of residence, weather conditions, age, and FEV1 (% predicted) were significantly related to quality of life in our patients. The Serbian version of AQLQ was highly reliable.