Changes in St. George's Respiratory Questionnaire (SGRQ) scores from baseline to 12 weeks for total samples (n=277), quitters (n=183) and continuous smokers (n=94). Changes in St. George's Respiratory Questionnaire (SGRQ) scores from baseline to 12 weeks for total samples (n=277), quitters (n=183) and continuous smokers (n=94). No statistically significant differences in changes in SGRQ scores were found between quitters and continuous smokers. Hiromi Tomioka et al. BMJ Open Resp Res 2014;1:e000047 ©2014 by British Thoracic Society