Evaluating the reported prevalence of type 2 diabetes mellitus by the Oguni diabetes registry using a two-sample method of capture-recapture

Background Capture-recapture methods have been widely employed in the study of wildlife populations and have recently been applied to count various hu man diseases and conditions. We have estimated the prevalence of type 2 dia betes mellitus by adjusting for the degree of undercount using a two-sample model of capture-recapture among men and women aged 50-69 in Oguni town, J apan. Methods Oguni town diabetes registry data were utilized as the first source . In the registry, only those who had experienced fasting plasma glucose of greater than or equal to 7.8 mmol/l (140 mg/dl) or 2 h plasma glucose afte r a 75 g oral glucose tolerance test (OGTT) of greater than or equal to 11. 1 mmol/l (200 mg/dl) were counted as having diabetes. A second source was a sample study selecting 200 men arid 200 women aged 50-69 randomly, which w as conducted in August 1991. A 75 g OGTT was done in the morning. The 1985 World Health Organization criteria were used to classify the diabetes statu s of the participants. A two-sample model of capture-recapture methods was employed to estimate the total number of cases of diabetes and determine th e ascertainment rates of the registry. Results The prevalence estimated by the diabetes registry was 7.1%. The pre valence from the sample study was 8.8% with a participation rate of 74%. Es timated prevalence employing the capture-recapture method was 13.1%. The as certainment rate of the registry was 53.8%. Conclusions Little is known about the prevalence of type 2 diabetes in loca l areas in Japan, the US and the world. Capture-recapture methods are likel y to provide a means to accurately assess the prevalence of diabetes.