A population-based study of tuberculosis case fatality in Canada: do Aboriginal peoples fare less well?

SETTING: The Province of Alberta, Canada.

OBJECTIVES: To explore trends in tuberculosis (TB) case fatality, compare TB case-fatality rates by population group and determine prognostic factors associated with TB-related death in Alberta from 1996 to 2012.

DESIGN: Retrospective cohort analysis.

RESULTS: During the study years, all-cause TB case fatality fell from 10.7% to 6.3%; the fall was attributable to a change in population structure, as there were more foreign-born and fewer older cases with time. A stable 2% of TB cases died without treatment. Compared to other population groups, Canadian-born Aboriginal case patients were more likely to die without treatment and to die younger. Of TB deaths that were TB-related, 68.9% occurred before or during the initial phase of treatment; of these, TB was a contributory cause of death in 77.5%, i.e., another medical condition was the primary cause of death. In multivariate analysis, age >64 years, aboriginality and miliary/disseminated or central nervous system disease were independent predictors for TB-related death.

CONCLUSION: Preventive therapy for those with latent tuberculous infection and a high-risk medical condition, early diagnosis of disease, and special support of older, Aboriginal or comorbid cases, once diagnosed, are necessary to further minimise TB case fatality in Alberta, Canada.