Reliability and validity of the St George's Respiratory Questionnaire for asthma.

BACKGROUND

The St George's Respiratory Questionnaire (SGRQ) is a self-administered questionnaire that has been used to evaluate the health-related quality of life of patients with chronic respiratory diseases.

OBJECTIVE

To assess the validity and reliability of the SGRQ for a large population with asthma.

DESIGN

We used the previously developed Korean version of the SGRQ (SGRQ-K) to assess 676 asthma patients enrolled from the Cohort for Reality and Evolution of Adult Asthma in Korea study. Cronbach's α was used to assess test reliability and Pearson's correlation coefficient was used to assess the correlation between SGRQ scores and various clinical factors.

RESULTS

The total SGRQ-K score had acceptable reliability (Cronbach's α = 0.92). The total SGRQ-K score was significantly correlated with symptom duration (r = 0.157, P < 0.001), pulmonary function (% FEV(1) of predicted r = -0.314, P < 0.001; % FVC of predicted r = -0.224, P < 0.001; FEV(1)/FVC r = -0.224, P < 0.001), asthma severity (r = 0.278, P < 0.001) and history of asthma exacerbation.

CONCLUSION

With the exception of the SGRQ-K symptoms, SGRQ-K is a reliable and valid test for evaluation of the quality of life of patients with asthma. Scores were well correlated with duration of symptoms, lung function and previous history of asthma exacerbation.