Tuberculosis-related deaths in Queensland, Australia, 1989-1998: characteristics and risk factors

OBJECTIVE

To review factors associated with TB-related deaths in Queensland, Australia.

DESIGN

Review of data for TB patients dying before treatment completion; demographic and clinico-pathological comparison of TB-related deaths with other notified patients after exclusion of losses to follow-up; matched case-control study of co-morbid conditions in patients under 75 years.

RESULTS

Of 1003 tuberculosis cases notified between 1989 and 1998, 127 died before completing anti-tuberculosis treatment. Tuberculosis was the main cause of death in 53 cases, a significant contributor in 34 and unrelated in 40, giving a TB-related case fatality rate of 8.7%. Decedents were older on average, except among indigenous Australians (IA); age-adjusted case fatality rates did not vary significantly among ethnic groups. Pulmonary and disseminated TB, coexistent malnutrition, renal disease and liver disease increased the risk of death. HIV infection increased the risk of dying, but was uncommon among Queensland cases. Neither sputum smear positivity nor drug resistance was associated with risk of death. Twenty-five TB-related deaths occurred before diagnosis, with significant overrepresentation of IA. Most had serious co-morbidities and symptomatic pulmonary disease. Seven socially or geographically isolated decedents did not access documented health care for tuberculosis.

CONCLUSIONS

Fatality was related to older age, disseminated disease and co-morbidity. Dying undiagnosed from tuberculosis was associated with respiratory co-morbidity and social and geographical isolation, mainly in the aged in low TB risk populations and in IA in remote regions.