Determinants of mortality before start of and during tuberculosis treatment among elderly patients: a population-based retrospective cohort study

BACKGROUND: people with weakened immunity because of age or co-morbidities comprised the fastest growing portion of tuberculosis (TB). Higher mortality before or during TB treatment was observed. In spite of the increasing longevity worldwide, surveys focussing specifically on elderly TB are scarce. OBJECTIVE: to identify prognostic factors of mortality before and during TB treatment among the elderly. METHODS: we provided a retrospective cohort study of patients aged 65 and above with pulmonary TB in an Asian city with ageing population. A total of 2,546 patients were enrolled, including 743 (29.2%) cases aged 85 or beyond. Study subjects were categorised by treatment outcomes: treatment success, death prior to TB treatment or death during TB treatment. Demographics and laboratory findings were compared between the three groups. RESULTS: after controlling for potential confounders, advanced age was the leading determinant of mortality. Adjusted odds ratios (AORs) of death during treatment were 1.79 (aged 75-84) and 3.43 (aged 85 and above) while comparing with patients aged 65-74. AORs of death prior to treatment were 2.95 and 5.66. Other prognostic factors included malignancy, end-stage renal disease receiving dialysis, need of intensive or long-term care, result of sputum acid-fast bacilli examination, findings of pleural effusion on chest X-ray and educational level. CONCLUSION: this research manifested significant determinants of mortality in elderly patients prior to or during TB treatment. High awareness, timely intervention and close monitoring of treatment are recommended to older TB patients, especially with the properties mentioned in this study.