Pediatric asthma quality of life questionnaire: validation in children from Singapore.

"Quality of Life" is a multidimensional measure encompassing the physical, emotional and social functioning of the child. The asthma specific questionnaire contains 23 questions (items) in three areas (domains) of activity, symptoms and emotions. The objective of the present study was to validate the Paediatric Asthma Quality of Life Questionnaire "PAQLQ"(copyright 1991 McMaster University). If the questionnaire is valid, a change in the child's asthma will be accompanied by a change in the "Quality of Life" questionnaire score. The questionnaire was administered twice over four weeks and the child's asthma status was assessed concurrently. Two groups were thus identified; Group A = unchanged asthma, Group B = changed asthma. Forty-seven children, aged 7 to 14 years, completed the study. Reliability of the questionnaire shows an intraclass-correlation coefficient of only 0.71. Cross-sectional construct validity was demonstrated by a significant correlation between the whole questionnaire and the clinical asthma score (p<0.001) but not in the separate domains. Longitudinal construct validity was also demonstrated by the significant correlation between change in the total questionnaire score, but not separate domains, with change in the child's asthma score (p<0.05). Responsiveness was shown by a significant difference in the magnitude of the change in the questionnaire score between the two groups (p<0.001), but again not in the separate domains. It was concluded that the questionnaire was validated as a whole but not in as convincing a manner, as has been done by others, and we are therefore in a position to advise caution in its application in our population.