GENERAL PRACTICE Self testing for diabetes mellitus

Objective-To develop a simple, economically viable, and effective means of population screening for diabetes mellitus. Design-A postal request system for self testing for glycosuria with foil wrapped dipsticks. Preprandial and postprandial tests were compared with a single postprandial test. The subjects were instructed how to test, and a result card was supplied on which to record and return the result. All those recording a positive test result and 50 people recording a negative result were invited for an oral glucose tolerance test. SettingGeneral practice in east Suffolk, list size 11534. Patients-All subjects aged 45-70 years registered with the practice were identified by Suffolk Family Health Services Authority (n= 3057). The 73 subjects known to have diabetes from the practice's register were excluded, leaving 2984 subjects, 2363 (79-2%) of whom responded. 1167 subjects completed the single test and 1196 the two tests. Main outcome measures-Response rate and number of patients with glycosuria. Sensitivity, specificity, and positive predictive value of a single postprandial test and preprandial and postprandial tests. Number of new cases of diabetes identified and cost of screening. Results-Of the patients completing the single postprandial test, 29 had a positive result; an oral glucose tolerance test showed that eight (28%) had diabetes, six (21%) impaired glucose tolerance, and 14 (48%) normal glucose tolerance. 44 of the group who tested before and after eating had a positive result; nine (20%) had diabetes, five (11%) impaired tolerance, and 26 (11%) normal tolerance. Screening cost 59p per subject and £81 per case detected. Of the 17 people with previously undiagnosed diabetes, eight were asymptomatic and 11 had not visited their general practitioner in the past three months. Conclusions-A postal request system for self testing for postprandial glycosuria in people aged 4570 is a simple and effective method of population screening for diabetes mellitus.