Validity and Reliability of the St. George's Respiratory Questionnaire in Asthmatic Patients

Abstract

RationaleAsthma is a chronic respiratory disease which can affect health related quality of life and finally cause disability. Therefore, adequate and valid assessment of quality of life by questionnaire is one of very important tools in monitoring for level of control in asthmatics.St George's Respiratory Questionnaire (SGRQ), a self-administered questionnaire has been used for evaluation of quality of life in chronic obstructive lung disease and asthma. However, the validity and reliability of SGRQ were not proved in large population of asthmatic patients yet.MethodsWe used Korean version of SGRQ permitted by the author previously. We analyzed 688 patients of asthma recruited from ‘Cohort for Reality and Evolution of Adult Asthma in Korea’ (COREA) since the year of 2005. Statistically, we used Cronbach's alpha coefficient for reliability and Pearson's coefficient for the correlation between SGRQ scores and various clinical factors.ResultsCronbach's alpha reliability coefficient was 0.92 for total score, 0.49 for the domain of symptoms, 0.88 for activity, and 0.88 for impacts. The correlation coefficients between the total score and symptom duration, diagnosis duration, treatment duration, previous hospital visit due to exacerbation, FVC (predicted %), FEV1 (predicted %), and FVC/FEV1 were 0.179 (p < 0.001), 0.080 (0.140), -0.043 (0.467), -0.163 (<0.001), -0.197 (<0.001), -0.312 (<0.001), and -0.199 (<0.001) respectively.ConclusionsSGRQ was a reliable and valid test of quality of life for patients with asthma, and scores were well correlated with duration of symptom, lung function, and previous exacerbation history. RationaleAsthma is a chronic respiratory disease which can affect health related quality of life and finally cause disability. Therefore, adequate and valid assessment of quality of life by questionnaire is one of very important tools in monitoring for level of control in asthmatics.St George's Respiratory Questionnaire (SGRQ), a self-administered questionnaire has been used for evaluation of quality of life in chronic obstructive lung disease and asthma. However, the validity and reliability of SGRQ were not proved in large population of asthmatic patients yet. Asthma is a chronic respiratory disease which can affect health related quality of life and finally cause disability. Therefore, adequate and valid assessment of quality of life by questionnaire is one of very important tools in monitoring for level of control in asthmatics. St George's Respiratory Questionnaire (SGRQ), a self-administered questionnaire has been used for evaluation of quality of life in chronic obstructive lung disease and asthma. However, the validity and reliability of SGRQ were not proved in large population of asthmatic patients yet. MethodsWe used Korean version of SGRQ permitted by the author previously. We analyzed 688 patients of asthma recruited from ‘Cohort for Reality and Evolution of Adult Asthma in Korea’ (COREA) since the year of 2005. Statistically, we used Cronbach's alpha coefficient for reliability and Pearson's coefficient for the correlation between SGRQ scores and various clinical factors. We used Korean version of SGRQ permitted by the author previously. We analyzed 688 patients of asthma recruited from ‘Cohort for Reality and Evolution of Adult Asthma in Korea’ (COREA) since the year of 2005. Statistically, we used Cronbach's alpha coefficient for reliability and Pearson's coefficient for the correlation between SGRQ scores and various clinical factors. ResultsCronbach's alpha reliability coefficient was 0.92 for total score, 0.49 for the domain of symptoms, 0.88 for activity, and 0.88 for impacts. The correlation coefficients between the total score and symptom duration, diagnosis duration, treatment duration, previous hospital visit due to exacerbation, FVC (predicted %), FEV1 (predicted %), and FVC/FEV1 were 0.179 (p < 0.001), 0.080 (0.140), -0.043 (0.467), -0.163 (<0.001), -0.197 (<0.001), -0.312 (<0.001), and -0.199 (<0.001) respectively. Cronbach's alpha reliability coefficient was 0.92 for total score, 0.49 for the domain of symptoms, 0.88 for activity, and 0.88 for impacts. The correlation coefficients between the total score and symptom duration, diagnosis duration, treatment duration, previous hospital visit due to exacerbation, FVC (predicted %), FEV1 (predicted %), and FVC/FEV1 were 0.179 (p < 0.001), 0.080 (0.140), -0.043 (0.467), -0.163 (<0.001), -0.197 (<0.001), -0.312 (<0.001), and -0.199 (<0.001) respectively. ConclusionsSGRQ was a reliable and valid test of quality of life for patients with asthma, and scores were well correlated with duration of symptom, lung function, and previous exacerbation history. SGRQ was a reliable and valid test of quality of life for patients with asthma, and scores were well correlated with duration of symptom, lung function, and previous exacerbation history.