Validation of the Portuguese version of the Asthma Quality of Life Questionnaire [AQLQ-M] by Marks.

Quality of Life is one of the leading evaluations in the diagnosis, therapy and investigation of patients with asthma. The aim of this study was to evaluate the psychometric properties of the Portuguese version of the Asthma Quality of Life Questionnaire (AQLQ-M) designed by Marks in Australia. This questionnaire consists of 20 items describing the impact of asthma on patient's lifestyle and covers 4 dimensions (breathlessness, mood, social limitation and worrying). After a process of translation, backtranslation, and pretest, the Portuguese version of AQLQ-M was administered to 82 adults asthmatics living in 3 different urban areas. The following data were also recorded: age, sex, main symptoms, duration of disease, hospital visits, severity of disease, and medication. All patients performed spirometry. The reliability study (internal consistency with Cronbach's alpha coefficient and inter-item correlation analysis) gave satisfactory results (range of r= 0.58 to 0.94; a= 0.91 to 0.97). Results for construct validity shown that the breathlessness dimension presented the largest numbers of significant correlations with the most important clinical variables of asthma. In conclusion, this study has shown that the Portuguese version of the AQLQ-M has good psychometric properties, and is suitable for use on individual patients with asthma in our country.