Contribution of post-TB sequelae to life-years and quality-adjusted life-years lost due to TB disease in the United States, 2015-2019
Authors: Menzies Nicolas A. , Marks Suzanne M. , Hsieh Yuli L. , Swartwood Nicole A. , Asay Garrett R. Beeler , Skarbinski Jacek , Horsburgh C. Robert , Cohen Ted 
Published: October 2024

Background

Individuals surviving TB disease may experience chronic sequelae that reduce survival and quality-of-life. These post-TB sequalae are not generally considered in estimates of the health impact of TB disease. We estimated reductions in life expectancy and quality-adjusted life expectancy for individuals developing TB disease in the United States, including post-TB sequelae.

Methods

We extracted national surveillance data on individuals diagnosed with TB during 2015-2019, including demographics, vital status at diagnosis, treatment duration, treatment outcome, and co-prevalent conditions. Using a mathematical model we simulated life expectancy and quality-adjusted life-years (QALYs) for the TB cohort, as compared to a no-TB counterfactual. We disaggregated results to report the proportion due to post-TB sequelae, and stratified outcomes by age, sex, and race.

Findings

Estimated life expectancy after TB diagnosis was 30.3 (95% uncertainty interval: 29.9, 30.7) years for the TB cohort versus 32.3 (31.9, 32.7) without TB, a difference of 2.03 (1.84, 2.21) years and 1.93 (1.69, 2.18) QALYs. Life-years lost were greatest for 65-74-year-olds versus other age groups, for men versus women, and for American Indian or Alaska Native individuals versus persons from other race/ethnicities. Overall, 41% (35, 46) of life-years and 48% (42, 54) of QALYs lost were estimated to result from post-TB sequelae.

Interpretation

In the United States, a substantial fraction of the life-years and QALYs lost from TB are attributable to post-TB sequelae. Evidence is needed on approaches to prevent and repair post-TB lung damage, in the context of frequent co-prevalent health conditions.

Funding

CDC.

Research in Context

Evidence before this study

Individuals surviving TB disease may experience reduced quality-of-life and elevated mortality rates, due to sequelae of the TB episode and pre-existing factors. We reviewed published literature to identify studies quantifying the impact of post-TB sequelae on life expectancy or other summary measures of health attainment. Using the following search terms: (tuberculosis) AND (“post-TB” OR “post-tuberculosis” OR “sequelae” OR “TB survivor” OR “pulmonary impairment” OR “delayed mortality”) AND (“life expectancy” OR “QALYs” OR “life years” OR “DALYs” OR “years of life lost”), we searched PubMed since inception until October 8 2024, without language restriction. Of the studies identified, most estimated health losses attributable to TB and post-TB in high-burden settings. Studies conducted in the United States reported results for specific geographic areas or trial populations, with estimates of the average life-years lost per TB case ranging from 1.5 to 7.0 years.

Added value of this study

For individuals developing TB in the United States, average life expectancy after TB diagnosis was estimated to be 30.3 (95% uncertainty interval: 29.9, 30.7) years, as compared to 32.3 (31.9, 32.7) years under a counterfactual scenario that estimated lifetime outcomes without TB. On average, TB was estimated to reduce life expectancy by 2.03 (1.84, 2.21) years, or 1.93 (1.69, 2.18) quality-adjusted life years (QALYs). Overall, 41% (35, 46) of life years lost and 48% (42, 54) of QALYs lost were from post-TB sequelae. Per person developing TB, TB-attributable reductions in life expectancy were greatest for 65-74-year-olds versus other age groups, for men versus women, and for American Indian/Alaska Native individuals versus other race/ethnicities.

Implications of all the available evidence

In this high-income setting with substantial healthcare resources, TB still represents a major health risk for those who develop the disease. Even for individuals who successfully complete TB treatment, lifetime health outcomes are poorer than for people who never had TB, and almost half of the QALYs lost from TB result from post-TB sequelae.