Introduction: the uses of epidemiological data

This chapter addresses the question of how epidemiological data can be used to plan services for people who suffer from schizophrenia. Morris (1975) has described seven uses of epidemiology: (i) assessment of incidence, prevalence, disability and mortality in defined populations; (ii) detailed description of the natural history of specific conditions and completion of the clinical picture of diseases; (iii) delineation of new syndromes and the description of associations between symptoms; (iv) calculation of morbid risk; (v) charting of historical trends; (vi) evaluation of health services in action; and (vii) identification of causal factors. However, what is striking in reviewing the literature on the epidemiology of schizophrenia is that, while both descriptive and analytical epidemiological studies can have direct implications for treatment, for care and for service provision, in fact they are rarely used for these purposes.

In most primary research and review papers on the epidemiology of schizophrenia, there are two points of emphasis: the aetiological implications of the findings and the description of course and outcome of the condition. The more practical consequences of the findings for service delivery are, by contrast, largely discounted. We shall advance the argument here that epidemiological data on schizophrenia should be exploited for their contributions both to the longer-term understanding of causation and course, and to match services to needs.

This chapter will describe ways in which this form of translation can be made.