Normative data and psychometric properties of the quality of life questionnaire for patients with diabetes mellitus

Introduction: Diabetes mellitus (DM) affectes multiple aspects of life in a diabetic patient. Theseinfluences does not take two much attention in the health system. The Persian version of quality of lifeassessment tools in these patients is not checked. The aim of this study was to examine the normative dataand some of the psychometric properties of the Persian version of quality of life questionnaire in patientswith diabetes mellitus in an Iranian population.Materials and Methods: Subjects were DM patients who were referred to health centers of Isfahan city(Iran) in 2007. A total number of 120 diabetic patients were selected through stratified randomizedsampling as well as equal number of matched control subjects. A demographic questionnaire, diabetesquality of life (DQOL) and WHO- quality of life (WHO-QOL) tools were administered to both groups.Results: The total mean score of QOL was relatively low in DM patients except for the domains ofworries. Using the chronbach’s alpha test, the reliability of the whole questionnaire and its subscales weredetermined to be 0.89 and 0.51 to 0.84, respectively. Also each question showed an internal positiveconsistency whit the whole questionnaire except for the 8th question of the effects domain (r= -0.21). Thecorrelation co-efficient of co-administration of the two questionnaires and their subscales were 0.63 0.60,0.39 and 0.05, respectively. The range of rough scores of the patients and the healthy subjects were 1.37to 3.97 and 1.18 to 3.37, respectively. The cut-off point was determined to be 2.06 based on the analysisof differentiations. The factor analysis was using the major elements and Varimax Rotation resulted in 6factors.Conclusion: Our findings showed that the DQOL has proper normative data and psychometricproperties in our samples. This questionnaire can be used in confidence by the health centers of Iran