Improved disease reporting: a randomized trial of physicians.

To determine if a heightened, passive surveillance system increases the number of physicians reporting two notifiable diseases during a six-month period.We conducted a randomized trail among 145 community-based primary care physicians in two counties in Eastern Ontario. Intervention group physicians received a three-part intervention aimed at improving their communication with the health unit to whom all physicians are mandated to report notifiable diseases. The control group physicians remained part of the usual disease reporting system. The outcome was assessed by a relative risk comparing the number of physicians reporting among the intervention group to that in the control group.Seventy physicians received the intervention and 75 physicians were in the control group. The relative risk for the number of physicians reporting at least one case was 5.9 (95% CI 2.6-13.2).The intervention had an impact on reporting of notifiable diseases by physicians.