Differences in antidiabetic drug utilisation between three different health systems in the same national region.

The consumption of antidiabetic drugs in a Spanish region (Extremadura) in the period 1986-1987 has been investigated by the "defined daily dose" (DDD) method. The study was done in three health care systems in the region: civil servants ("Mutualidad de Funcionarios Civiles del Estado: MUFACE") armed forces group ("Instituto Social de las Fuerzas Armadas: ISFAS") and the national system ("Instituto Nacional de la Salud: INSALUD"). The total consumption of antidiabetic drugs varied three-fold, ranging from 5,73 DDD per 1000 inhabitants per day (3,71 DDD per 1000 inhabitants per day for oral antidiabetic drugs and 2,02 DDD per 1000 inhabitants per day for insulin) in the civil servant group to 15,82 DDD per 1000 inhabitants per day (12 DDD per 1000 inhabitants per day for oral antidiabetic drugs and 3,82 DDD per 1000 inhabitants per day for insulins) in the armed forces. The differences were more pronounced for oral antidiabetics than for insulins. The utilization of insulin among the civil servants was about half of that by the two other groups. Of oral antidiabetics, sulphonylureas were the most frequently used by the three groups, and within them glibenclamide accounted for more than half of the DDDs, while biguanides were scarcely used in any group. The differences are difficult to assess, since they could be due to several factors, such as age-differences in the population studied, different prescribing habits, and differences in sociocultural level. The results justify further comparative studies of drug utilization in different health systems within the same region.