Factors affecting compliance with preventive treatment for tuberculosis at Mistassini Lake, Quebec, Canada

Non-compliance is the most important cause of failure of anti-tuberculous therapy throughout the world. In 1990 and 1991, an outbreak of tuberculosis occurred on the Mistassini Cree territory in Northern Quebec, Canada, and a number of cases of active tuberculosis occurred among known tuberculin-positive contacts who were non-compliant with preventive therapy. To better understand the factors affecting compliance with preventive treatment, a review of patients prescribed preventive treatment over the past 10 y was conducted. A freely-translated, interviewer-administered questionnaire was used to measure personal/lifestyle factors and knowledge/attitudes about tuberculosis. Clinic dossiers were reviewed to assess compliance. One hundred and two (102) subjects prescribed preventive treatment between 1981 and 1991 were interviewed, of whom 33.7% were judged to have been compliant. The most significant factor associated with compliance with preventive therapy was year of therapy. Between 1981 and 1985, 78% completed treatment, compared to less than 20% since 1986 (p < .0001). The major factor identified as associated with this sudden change was a shift in responsibility for tuberculosis treatment follow-up from native community health workers to non-native nurses in 1985/86. We conclude that tuberculosis control programs must be tailored to take into account the importance of cultural factors in promoting compliance with therapy.