The statistical analysis of national health insurance's database, containing a record of the care reimbursed to affiliated members and delivered drugs in the form of special pharmacy codes, enable us to evaluate the follow-up care given to diabetics, to update epidemiological information and to determine the actual cost of diabetes. The method used consisted in the identification of diabetics by isolating patients who received hypoglycemic agents during the 3-month inclusion period followed by a retrospective determination of total reimbursements made through the 128 local health offices (CPAM) located in metropolitan France in order to study the reimbursed care (medical consultations, procedures and drug prescriptions) given to diabetics over the preceding 12 month period. Considering that the pharmacy coding system was still incomplete at the time the study was undertaken, we had to verify that the population selected by the coding system was only partially operational, requiring a calculation involving weighted coefficients. Finally, we needed to take into account the fact that the resulting data contained virtually no information on facilities receiving a once a year total budget allocation (all public hospital).