A MODEL FOR EARLY DIAGNOSIS OF TYPE-2 DIABETES-MELLITUS IN PRIMARY HEALTH-CARE

The aim of the study was to determine the feasibility of conducting a case-finding programme for Type 2 diabetes mellitus in primary health care and to see whether random urinary glucose or random capillary blood glucose testing is the most suitable instrument for the early detection of Type 2 diabetes. Residents in the community of Laxa aged 35-64 years were subjected to testing during 1983-1987; those aged 65-79 were included from July 1985 and onwards. The urinary glucose testing was considered positive if a urinary dipstick was not unequivocally negative. The random blood glucose test was regarded as positive when greater-than-or-equal-to 8.0 mmol l-1. A diagnosis of Type 2 diabetes made within a follow-up period of 3 years from the initial examination was regarded as a positive outcome. Random blood glucose testing was performed on 3268 persons which was close to 85 % of the eligible population. Urinary glucose tests were missing in 67 subjects. The random blood glucose test was positive in 220 persons and the urinalysis in 42 persons. A total of 234 individuals had a positive test, out of which 66 new diabetic cases were found. Sixty-four of these were detected by the random blood glucose testing and 20 by the urinalysis. The sensitivity for the random blood glucose and urinary glucose testing was 73 and 23 %, the specificity was 95 and 99 %, the positive predictive value 29 and 48 %, and the negative predictive value 99 and 98 %, respectively. Random blood glucose testing is superior to urinary glucose testing in case finding for Type 2 diabetes and is well suited for use as a screening instrument in a primary health care setting.