title: Validity and specificity of the Persian version of the Saint George Respiratory Questionnaire.
abstract: BACKGROUND
  The Saint George Respiratory Questionnaire (SGRQ) is a well-known questionnaire for evaluating the quality of life in asthmatic patients. It has been translated to Persian and its validity and specificity should be evaluated for chronic obstructive pulmonary disease patients. In this study, we attempted to improve the questionnaire's adaptability to Persian culture and also evaluate its validity, specificity, and applicability among asthmatics at our tertiary referral center.
  
  
  METHODS
  Previously translated and psychometrically evaluated SGRQ for chronic obstructive pulmonary disease patients was made more adaptive to Persian. Upon acceptability of the questionnaire by a small group of patients, 301 asthmatics referred for spirometry and completed the form. Consistency was evaluated using Cronbach's α coefficient and validity was assessed by comparison of scores with other measures of asthma exacerbation. These measures included FEV1, patient's clinical presentation, visual analog scale (used to assess difficulty breathing), Katz activity index and section scores of the General Health Questionnaire, anxiety, depression, and social impact.
  
  
  RESULTS
  The study group included 165 female and 139 male asthmatics with a mean age of 44.4 ± 1.0 years. Measurement of consistency for the SGRQ revealed Cronbach's α to be 0.699 for symptoms, 0.805 for activity, 0.879 for impact, and 0.916 for the total questionnaire. By omitting question 8, time of wheezing during the day increased Cronbach's coefficient of the symptoms section to 0.719. Omitting "uselessness of respiratory drugs" from the impact section increased Cronbach's α to 0.881. However, scoring of the section then varied from the original questionnaire. A statistically significant correlation was found between the SGRQ sections and total score (using Katz index and General Health Questionnaire, p < .001).
  
  
  CONCLUSIONS
  Our study showed good validity and reliability for the Persian version of SGRQ for a population of asthmatics referred to our tertiary pulmonary clinic.
authors.affiliation: Department of Pulmonary Medicine, Masih Daneshvari Hospital, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Dar Abad, Tehran, Islamic Republic of Iran. saeid_ftafti@yahoo.com
authors.forename: Saeid Fallah
authors.initials: SF
authors.lastname: Tafti
authors.forename: Ali
authors.initials: A
authors.lastname: Cheraghvandi
authors.forename: Bahareh
authors.initials: B
authors.lastname: Mokri
authors.forename: Firouzeh
authors.initials: F
authors.lastname: Talischi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care / Q000706:statistics & numerical data; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000523:psychology*; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D004417:Dyspnea / Q000175:diagnosis; D004522:Educational Status; D004651:Employment / Q000706:statistics & numerical data; D005190:Family; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D029424:Pulmonary Disease, Chronic Obstructive / Q000523:psychology; D011788:Quality of Life; D011795:Surveys and Questionnaires; D014797:Vital Capacity / Q000502:physiology; D055815:Young Adult