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Istituto Superiore di Sanità
EpiCentro - L'epidemiologia per la sanità pubblica
Istituto Superiore di Sanità - EpiCentro


William B. Baine

Center for Outcomes and Effectiveness Research

Agency for Healthcare Research and Quality

Bethesda, Maryland, USA

 

Despite his lack of epidemiologic training, it was Virgil who expressed the spirit of the field when he wrote, "Happy is he who is able to know the causes of things" (1). For the epidemiologist, the recipe for this happiness lies in applying quantitative methods to data of high quality. The observations reported here by Battistella and Carlini in Treviso and by Campora and colleagues in Campania show how to exploit administrative data to epidemiologic ends. The eminent authority on health services research,  John Eisenberg, has written, "Epidemiologic research is a bedrock of health services research..." (2).

 

Besides the very word, "epidemics," we owe to the Hippocratic school two precious insights into how to know the causes of diseases. First, rather than turning to preconceived notions, begin at the bedside of the individual patient, accurately observing signs and symptoms, the natural history of the disease, and the effects of any therapeutic interventions. The second insight was the appreciation that diseases differ not only in how they appear in the individual but also in their behavior and spread in populations. The demonstration of disparities between groups in the diffusion of health services may indicate phenomena that require further analysis. In Treviso the increase with age in expenditures per capita was strikingly higher among men compared to women.  Is the discrepancy due to potentially preventable processes among the men? Could this be, also or instead, a case of undertreatment among women or perhaps of overtreatment among men?

 

To a great extent, the point of departure for clinical epidemiology is the demonstration of geographic variation in surgical operations and in other diagnostic and therapeutic measures with no apparent basis in medical need. Campania exhibits remarkable variation in the proportion of admissions to cardiac surgery units that are due to the most characteristic DRGs (Diagnosis Related Groups) as well as in the frequency with which specialized procedures are performed outside the region.

 

Thus the epidemiologist is charged with applying Hippocratic insights in order to know the causes of disturbances of structure and function, not only of our patients, but also of the health services themselves.