Association of Mortality and Years of Potential Life Lost With Active Tuberculosis in the United States

Abstract

Importance: Active tuberculosis (TB) disease leads to substantial mortality but is preventable through screening and treatment for latent TB infection. Early mortality after TB diagnosis (≤1 year) is well described, but delayed mortality (>1 year) among patients with active TB is poorly understood.

Objective: To compare early and delayed mortality and years of potential life (YPL) lost among patients with active TB disease vs an age-, sex-, and year of diagnosis-matched comparison cohort without active TB disease.

Design, setting, and participants: This retrospective cohort study, conducted in the integrated health system of Kaiser Permanente Northern California, included patients with microbiologically confirmed active TB disease from January 1, 1997, to December 31, 2017, and a control cohort matched by age, sex, and year of diagnosis. Multivariable models were used to adjust for demographic and clinical characteristics. Patients with active TB disease prior to 1997 were excluded. Data were analyzed from January 1, 2019, to January 31, 2020.

Exposure: Microbiologically confirmed TB disease.

Main outcomes and measures: Early (≤1 year after TB diagnosis) and delayed (>1 year after TB diagnosis) all-cause mortality.

Results: A total of 2522 patients who had active TB from 1997 to 2017 were identified, with 17 166 person-years of follow-up. The comparison cohort included 100 880 persons with 735 726 person-years of follow-up. In the active TB and comparison cohorts, similar percentages of persons were male (56.3% vs 55.6%), aged 45 to 64 years (33.7% vs 33.7%), and aged 65 years or older (24.7% vs 24.7%). Both early mortality (7.0%) and delayed mortality (16.3%) were higher among patients with active TB disease compared with those without active TB disease (1.1% and 12.0%, respectively). Patients with active TB disease had a significantly higher risk for early (adjusted hazard ratio [aHR], 7.29; 95% CI, 6.08-8.73) and delayed (aHR, 1.78; 95% CI, 1.61-1.98) mortality compared with the comparison cohort (P < .001). Active TB disease was associated with an adjusted -7.0 (95% CI, -8.4 to -5.5) YPL lost compared with the comparison cohort.

Conclusions and relevance: In this study, patients with active TB disease had significantly higher early and delayed all-cause mortality when adjusting for demographic and clinical characteristics. These findings suggest that TB prevention through screening and treatment of latent TB infection could reduce mortality and YPL lost due to active TB disease.

Figure.. Survival Probability Among Patients With Active Tuberculosis (TB) Disease Compared With an Age-, Sex-, and Date of Diagnosis–Matched Cohort of Patients Without Active TB Disease, Kaiser Permanente Northern California, 1997-2017