Epidemiology in community psychiatric research: common uses and methodological issues.
OBJECTIVE
Epidemiological principles underpin much medical research particularly that concerned with the planning and evaluation of health services, including research in community and social psychiatry. The aim of this paper is to review some of the common uses of epidemiology in community psychiatric research and to discuss some methodological issues that arise frequently in epidemiological research in community settings.


METHODS
This is a review of the relevant literature and of the work currently in progress in the department of psychological medicine of the university of Wales College of Medicine.


RESULTS
Among the many uses of epidemiology in health care, four are especially relevant in community psychiatric settings: the assessment of the mental health needs of the population (four approaches are described: the collection of routine data, surveys of existing patients, surveys of the general population and statistical modelling), the identification of risk factors of disease, the contribution to prevention and the assessment of the clinical effectiveness of health care interventions. The most important methodological issues include causal inference which in epidemiology takes the form of explaining the association between an exposure and disease (chance, bias, confounding, reverse causality and causality), the issue of confounding and how to adjust for it and issues arising in the context of specific study designs.


CONCLUSIONS
Epidemiology has become a set of methods used to investigate a wide range of clinical questions. Population based research is an essential part of clinical research but epidemiological knowledge is also needed by clinicians in order to critically appraise and interpret the scientific literature.
Skapinakis
P
P
Division of Psychological Medicine, Academic Unit, Monmouth House, University of Wales College of Medicine, Heath Park, Cardiff CF14 4XN, UK.
Lewis
G
G
D015982:Bias; D016022:Case-Control Studies; D003158:Community Psychiatry; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D003625:Data Collection; D019317:Evidence-Based Medicine; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology* / Q000517:prevention & control / Q000628:therapy; D015201:Meta-Analysis as Topic; D015233:Models, Statistical; D011634:Public Health; D016032:Randomized Controlled Trials as Topic; D012106:Research; D012307:Risk Factors