[Recourse to health care and drug consumption. Perspectives and conceptual framework]

This paper is based on an introductory review given at the seventh scientific meeting of the Association of French Speaking Epidemiologists on "Epidemiological Aspects of the Consumption of Pharmaceuticals". It notes that though there is a relatively close relationship between total health service spending and Gross Domestic Product, no such relationship exists for expenditures on the different components of health services. Countries with similar morbidity pyramids, economic and technical capacity have quite different pyramids of service. Pharmaceutical expenditures also show this variation. In 1975, a comparative survey showed that they varied from 0.68% of G.D.P. in Denmark to 1.89% in Italy, and from $28.6 per head in the United Kingdom to $90.9 in France. The largest variation is in the share of health expenditures allocated to pharmaceuticals, which though falling generally in developed countries, ranges from 9% in Sweden to 36% in Italy. Given these variations, a synthetic schema is outlined relating need, demand and use of health services, including pharmaceuticals. This schema is then elaborated to include the main factors influencing demand and use. They include 21 predisposing factors, (10 morbidity factors, 11 social and personal factors) and 4 enabling factors. Each of these factors is briefly explained. The conclusion is drawn that though the factors influencing pharmaceutical consumption are known, neither their respective influences nor their interactions are known. Epidemiological research has so far hardly scraped the surface of this problem, and the bulk of the work required in this field still remains to be done.