Prevalence and determinants of tuberculin reactivity among physicians in Edmonton, Canada: 1996-1997

Background Health care workers (HCW) have historically borne a heavy burden of tuberculosis (TB) infection and disease. Unfortunately, physicians are rarely included in HCW surveys of tuberculin exposure and infection. Methods The prevalence and risk factors for tuberculin reactivity were dete rmined for a sample of the 1732 licensed physicians in Edmonton. Stratified random sampling was used to select 554 specialists and 219 general practit ioners. These physicians were contacted by means of an introductory letter and a follow-up telephone call to solicit participation. All eligible physi cians were asked to complete a questionnaire and those with either no recor ded positive tuberculin test or a previously negative result were two-step tuberculin skin tested. Results In total, 560 physicians (72.4%) participated in the study. The ove rall tuberculin reactivity for this population was 45.9%. Using logistic re gression analysis, we determined that risk factors for reactivity were aged over 45 years, of foreign-birth, previous Bacillus Calmette-Guerin (BCG) v accination, foreign practice experience, and being a respiratory medicine s pecialist. Conclusion The prevalence of tuberculin reactivity among physicians is cons iderably higher than estimates for the general Canadian population. This ob served excess risk may be associated with factors linked to their medical p ractice. The high participation rate suggests physician willingness to part icipate in this type of research, and emphasizes the need to include them i n routine HCW surveillance.