A minimal prevalence study of diagnosed diabetes in Newfoundland and Labrador.

A two-stage random probability sampling survey of the medical charts of family physicians in Newfoundland and Labrador was done; the first stage sampled physicians randomly, in proportion to the 5 health districts of the province; the second stage took a quota sample of the physicians' charts. The survey revealed a total population minimal prevalence rate of diagnosed diabetics of 3.55% (95% confidence limits 2.55, 4.55). This rate is higher than that found in the only other provincial survey done in Canada (the Prince Edward Island survey). Of diagnosed diabetics, 40% were found to be using insulin. This proportion is higher than other rates in North America. The prevalence rate was slightly higher in males (3.7%) than in females (3.4%).