An information system for family practice. Part 2: The value of defining a practice population.

The gathering of information on the practice population is essential for practice monitoring, preventive medicine, and research. The minimum necessary information is the age and sex of individuals cared for in the practice. This allows the expression of age-sex specific morbidity rates for the at-risk population. In the Department of Family Medicine, University of Western Ontario, practice census information has been used to determine the suitable size for a teaching practice, the representativeness of our practices in terms of age, sex, residence location, and morbidity, and for the production of at-risk registers based on age and sex.