Method of estimating the disposition of drugs in the Danish population by sampling reimbursed prescriptions.

A method by which for a small cost it is possible to obtain a quantitative expression for the utilization, disposition and cost of drugs in a Danish county of 500,000 inhabitants. The procedure makes it possible to follow reimbursed preparations, i. e., drugs considered essential for the treatment of diseases. The sale, in D kr., of reimbursed preparations to individuals comprises about 80% of the sale of preparations requiring prescription. And in turn the sale of the latter amounts to 80% of total drug sales to single subjects. The method is based on systematic utilization of all the information available on each prescription; concepts of 'Entry Parameters', 'Calculated Units' and 'Derived Units' was discussed; the 'units' concern frequency of prescription and age- and sex specific dose-frequencies (weight units or defined daily doses -- DDD's). The possibility of creating a base for calculation of the frequency of certain diseases and of side-effects of drugs is mentioned, and examples of the application of the method to certain categories of patients and to certain drugs are given. From limitations of the method it is concluded that it should be considered as a supplement to other complete methods for the study of drug consumption.