Occupational epidemiology and efficiency evidence

Occupational medicine is undergoing major changes and the question of "evidence" seems essential at this turning point. We need to update knowledge, adjust methods and verify the efficacy of interventions. If this is not done, the discipline might be reduced to just passive application of legislation with a consequent reduction of occupational medicine's professional and scientific content. Procuring evidence is objectively more difficult in the field of prevention than in the clinical field; however, those difficulties should be addressed and not simply handled in a trite way. In occupational medicine there is special opportunity to combine a "population" approach (tending to reduce exposure of the entire population) with a "high risk" approach where particularly susceptible subjects are identified and treated with targeted interventions. The contribution of epidemiology to the goal of underpinning a renewed occupational health practice with proves of evidence, mainly rests in suggesting methods able to 1- guarantee the validity of the observation of relationships between exposures and effects; 2- put together observations and studies independently conducted on the same issue and produce a combined quantitative evaluation; 3- set up ad hoc studies for evaluating prevention measures in progress. Health surveillance programs represent a particularly fertile soil for evaluation research and evidence accrual, however they are not sufficiently taken into consideration for this purpose, and relevant studies are few. A renewed cooperation involving occupational medicine and health centres is necessary to achieve that goal.