Mortality during tuberculosis treatment in South Africa using an 8-year analysis of the national tuberculosis treatment register

Abstract

In 2011, the South African HIV treatment eligibility criteria were expanded to allow all tuberculosis (TB) patients lifelong ART. The impact of this change on TB mortality in South Africa is not known. We evaluated mortality in all adults (≥ 15 years old) treated for drug-susceptible TB in South Africa between 2009 and 2016. Using a Cox regression model, we quantified risk factors for mortality during TB treatment and present standardised mortality ratios (SMR) stratified by year, age, sex, and HIV status. During the study period, 8.6% (219,618/2,551,058) of adults on TB treatment died. Older age, male sex, previous TB treatment and HIV infection (with or without the use of ART) were associated with increased hazard of mortality. There was a 19% reduction in hazard of mortality amongst all TB patients between 2009 and 2016 (adjusted hazard ratio: 0.81 95%CI 0.80–0.83). The highest SMR was in 15–24-year-old women, more than double that of men (42.3 in 2016). Between 2009 and 2016, the SMR for HIV-positive TB patients increased, from 9.0 to 19.6 in women, and 7.0 to 10.6 in men. In South Africa, case fatality during TB treatment is decreasing and further interventions to address specific risk factors for TB mortality are required. Young women (15–24-year-olds) with TB experience a disproportionate burden of mortality and interventions targeting this age-group are needed.

Linkage to care and treatment outcomes for patients diagnosed with drug-susceptible tuberculosis using Xpert MTB/RIF assay in Thaba-Tseka district in Lesotho

“…The TB mortality rate remained relatively constant from 2016 to 2020 in this study, with no specific trend. A South African study reported a slightly low cumulative mortality rate of 8.6% for adult patients who initiated drug-susceptible TB treatment ( Osman et al., 2021 ). The TB mortality rate in Thaba-Tseka district does not meet the 2020 ‘End TB strategy’ target of a 35% reduction in mortality rate from 2015.…”

Time trends in tuberculosis mortality across the BRICS: an age-period-cohort analysis for the GBD 2019

“…However, among HIV-negative females in China, tuberculosis mortality risks were higher in younger groups, quite similar to the trends reported in Spain and Hong Kong. Osman et al 33 explained that younger females might have few other causes of death, and the proportion of other causes of death increased in the older age group. In China, the prevalence of malnutrition among women aged 15-24 years was the highest among women aged 15-49 years, 34 which could lead to a decrease in immunity and an increased risk of tuberculosis infection and death.…”

Drivers of sex differences in the South African adult tuberculosis incidence and mortality trends, 1990-2019

“…For mortality, the M:F ratio reduced to 0.93 (i.e., higher mortality in females). This is possibly because females' 'background' mortality (deaths not related to HIV and tuberculosis, e.g., due to violence) is much lower than in males 31,37 ; and therefore, more females survive to older ages than males. In our model we assumed tuberculosis mortality rates increase with age (Table 1), people in older age groups (55 + years) contribute disproportionately to tuberculosis mortality, and the majority are likely females.…”

“…In our model we assumed tuberculosis mortality rates increase with age (Table 1), people in older age groups (55 + years) contribute disproportionately to tuberculosis mortality, and the majority are likely females. The lower female background mortality rates may also explain why in females compared to males, tuberculosis mortality may appear higher relative to background mortality 31 , although their absolute tuberculosis mortality risk is low.…”

“…Although the base rates of tuberculosis mortality on treatment were initially set the same in males and females, these base rates were adjusted to re ect sex differences in health-seeking patterns. We based treatment outcome assumptions on the electronic tuberculosis treatment register (ETR.net) (supplementary material) 31 .…”