Validity Of Brief Asthma Control Questionnaires In Chinese Patients

Background: The study is to assess the validity of Asthma Control Test in Chinese Patients. We also try to develop a questionnaire according to the characteristics of Chinese asthma patients.Methods: 3 questionnaires were administered to 305 asthma patients from 10 teaching hospitals across China including Asthma Control Test, Asthma Control Questionnaire and the 30-second asthma test. Asthma specialists rated the asthma control by patients'symptoms, medications and forced expiratory volume in first second. Reliability, empirical validity and screening accuracy were conducted for Asthma Control Test scores. Screening accuracy was compared among 3 questionnaires.We investigated the medication of the enrolled 305 asthma patients. According to the result and the asthma control goal defined in the GINA 2006, we developed the Asthma Control Assessment. We mailed the Asthma Control Assessment questionnaire to those asthma patients mentioned above and told them to complete it. Reliability, empirical validity and screening accuracy were conducted for Asthma Control Assessment. Screening accuracy was compared among Asthma Control Assessment, Asthma Control Test, Asthma Control Questionnaire and the 30-second asthma test.Results: The internal consistency reliability of the 5-item Asthma Control Test was 0.854. The correlation coefficient between Asthma Control Test and the specialists'rating was 0.729. Asthma Control Test scale scores discriminated between groups of patients differing in the percent predicted forced expiratory volume in first second (F=26.06, P<0.0001), the specialists'rating of asthma control (F=88.24, P<0.0001) and the Asthma Control Questionnaire scores (F=250.57, P<0.0001). The optimal Asthma Control Test cut-point for Chinese patients was 19. Asthma Control Test showed no significant difference with Asthma Control Questionnaire in the %correctly classified, while the %correctly classified of Asthma Control Test is higher than that of 30-second asthma test.Among 305 patients, 45 patients used theophylline as rescue medication to relieve their asthma exacerbation, which takes 14.8%. 75 patients completed Asthma Control Assessment. The internal consistency reliability of Asthma Control Assessment was 0.818. The correlation coefficient between Asthma Control Assessment and the specialists'rating was 0.704. Asthma Control Assessment scale scores discriminated between groups of patients with different asthma control. The optimal Asthma Control Assessment cut-point for Chinese patients was 11. Asthma Control Assessment showed no significant difference with Asthma Control Test and Asthma Control Questionnaire in the %correctly classified, while the %correctly classified of Asthma Control Assessment is higher than that of 30-second asthma test.Conclusion: Being an effective as well as easy method for assessing asthma control, Asthma Control Test is practicable in China. Asthma Control Assessment is an easy and effective instrument for asthma control evaluation, which conforms to the characteristics of Chinese asthma patients'medication.