بررسي اختلاف بين شركت كنندگان و امتناع كنندگان از شركت در مطالعه قند ليپيد تهران

Differences between respondents and non-respondents in the Tehran Lipid and Glucose Study (TLGS)

Introduction: We aimed to determine response rate and to compare respondents and non-respondents in the Tehran Lipid and Glucose study according to their health status. Materials and Methods: In a nested case-control study conducted as a part of TLGS, questionnaires of the study were filled out, during face to face interviews by participants aged 20 years and over who had refused to participate the first time they were invited; their data such as demographic (age, sex, marital status, and education) and medical and /or family history of cardiovascular or ischemic heart disease, stroke, diabetes, hypertension, and dyslipidemia were compared with a control group of respondents . Results: After the first invitation, 15010 out of 27340 individuals agreed to participate in the study (54.9% response rate). From among non-respondents, 1370 were selected randomly and compared to 9994 controls. Non-respondents were younger than respondents. 55.6% of non-respondents and 46% of respondents were in the 20-39 year-old age group (p<0.001). The majority of non respondents were male, single, employed, and had higher educational levels than respondents (p<0.001). As far as the medical and/or familial history of the diseases mentioned was concerned, the non-respondents were in a better condition than the respondents; they used less drugs (p<0.001). Prevalence of smoking was higher in non-respondents than in respondents (16.1% vs 11.8%, p<0.001). The 3 foremost reasons expressed by non respondents were "I do not have time" (45.9%) "I do not need to be examined" (15.1%), and "I am not interested" (7.7%). Conclusion: Although, non-respondents were more healthy than respondents, this study has shown that need for medical care is an important issue in Iranian population studies. Appropriate and effective education is needed to motivate participation in population based surveys.