BACKGROUND: No currently available asthma symptom diary has sufficient validation to be recommended for use as a core asthma outcome measure. OBJECTIVE: The objective of this study was to provide validation data for the 10-item asthma symptom diary (ASD). METHODS: Data were collected in a 4-week prospective, observational study. Subjects completed 3 study visits, completing the ASD twice daily at home for 28 days. Psychometric properties in terms of dimensionality, reliability, validity, and responsiveness were assessed. RESULTS: Data from 276 subjects were analyzed; mean age was 42.9 (standard deviation [SD] = 16.4) years, mean asthma duration was 23.3 (SD = 16.8) years, and 69.6% were female. Confirmatory factor and Rasch analysis supported the ASD as unidimensional and adequately measuring the spectrum of asthma symptom severity. High Cronbach's α (0.94) and intraclass correlation coefficients (0.89-0.95) supported reliability. A high correlation between the 7-day average ASD score and the Asthma Control Questionnaire (ACQ) total score (r = 0.75) and Asthma Quality of Life Questionnaire total scores (r = -0.76), and a moderate correlation with FEV1% predicted (r = -0.30) supported convergent validity. Significant differences (P < .001) between groups classified by ACQ scores supported known-group validity. The 7-day average ASD scores were responsive to change, with significantly higher score changes (P < .001) in responders versus nonresponders. Minimally important differences were calculated and found to be in the range of 0.1-0.3. CONCLUSION: Results of this study indicated that the ASD is a reliable and valid asthma symptom measure for use in adult and adolescent asthma patients to evaluate the effect of treatment on asthma in clinical trials.
BACKGROUND: No currently available asthma symptom diary has sufficient validation to be recommended for use as a core asthma outcome measure. OBJECTIVE: The objective of this study was to provide validation data for the 10-item asthma symptom diary (ASD). METHODS: Data were collected in a 4-week prospective, observational study. Subjects completed 3 study visits, completing the ASD twice daily at home for 28 days. Psychometric properties in terms of dimensionality, reliability, validity, and responsiveness were assessed. RESULTS: Data from 276 subjects were analyzed; mean age was 42.9 (standard deviation [SD] = 16.4) years, mean asthma duration was 23.3 (SD = 16.8) years, and 69.6% were female. Confirmatory factor and Rasch analysis supported the ASD as unidimensional and adequately measuring the spectrum of asthma symptom severity. High Cronbach's α (0.94) and intraclass correlation coefficients (0.89-0.95) supported reliability. A high correlation between the 7-day average ASD score and the Asthma Control Questionnaire (ACQ) total score (r = 0.75) and Asthma Quality of Life Questionnaire total scores (r = -0.76), and a moderate correlation with FEV1% predicted (r = -0.30) supported convergent validity. Significant differences (P < .001) between groups classified by ACQ scores supported known-group validity. The 7-day average ASD scores were responsive to change, with significantly higher score changes (P < .001) in responders versus nonresponders. Minimally important differences were calculated and found to be in the range of 0.1-0.3. CONCLUSION: Results of this study indicated that the ASD is a reliable and valid asthma symptom measure for use in adult and adolescent asthmapatients to evaluate the effect of treatment on asthma in clinical trials.
Authors: Clara Padró; Diego Gutiérrez; Francisco Moreno; Antonio Parra; Manuel J Rial; Ramón Lleonart; Carla Torán-Barona; José L Justicia; Albert Roger Journal: Immun Inflamm Dis Date: 2022-05
Authors: Diane Whalley; Gary Globe; Rebecca Crawford; Lynda Doward; Eskinder Tafesse; John Brazier; David Price Journal: Health Qual Life Outcomes Date: 2018-08-03 Impact factor: 3.186
Authors: Andrew Menzies-Gow; Gene Colice; Janet M Griffiths; Gun Almqvist; Sandhia Ponnarambil; Primal Kaur; Gennaro Ruberto; Karin Bowen; Åsa Hellqvist; May Mo; Esther Garcia Gil Journal: Respir Res Date: 2020-10-13