[The quality of life in asthma: an evaluation of the AQLQ questionnaire for its use on a Spanish population. Asthma Quality of Life Questionnaire].

The study of morbidity in asthma requires consideration not only of standard physiopathologic and function parameters, but also of the impact the disease has on the patient's life-style as he or she perceives it and evaluates it. The quantification of this factor, known as health-related quality of life (HRQL), is achieved by administering questionnaires specially designed for the purpose. We analyzed the reliability, content validity and construct validity (convergence and divergence) of one instrument, the Asthma Quality of Life Questionnaire (AQLQ) designed by Marks and colleagues. This questionnaire covers 4 dimensions (breathlessness, mood, social limitation and worrying) and gives a total score. After a process of translation and back translation the AQLQ was administered to 102 adult asthmatics living in an urban center, all of whom had been stable for at least the preceding 4 weeks. The following data were recorded: age, sex, duration of disease, FEV1, medication, dyspnea, hospital visits, nighttime symptoms and severity of disease (from the patient's own point of view and according to the scale of the International Consensus Report [ICR]). The reliability study (internal consistency with Crombach's alpha coefficient and inter-item correlation analysis) gave satisfactory results in all cases (range of r = 0.39 to 0.78; alpha = 0.78 to 0.91). Content validity (factorial analysis of the main components, oblique and orthogonal rotations) was less satisfactory, although 4 factors were found; these factors adjusted relatively well to one of the proposed sub-scales and together explained 65.2% of the total variance.(ABSTRACT TRUNCATED AT 250 WORDS)