Mortality and lost to follow-up among Tuberculosis patients on treatment in Meru County, Kenya: a retrospective cohort study

Tuberculosis (TB) remains a leading cause of death globally. Patients who get lost-to-follow-up (LTFU) during TB treatment have high risk of relapse, mortality, treatment failure and developing Multidrug resistant TB. Empirical data to monitor long-term TB treatment outcomes in low-and-middle income countries (LMICs) are sparse. We determined proportion of TB patients who die or are LTFU during six months of treatment and identified factors independently associated with mortality or LTFU. A retrospective cohort using data from routine Meru County TB surveillance system. We included 38020 records of TB patients aged ≥15 years on treatment 2012 to 2022. TB treatment outcomes of interest were LTFU or death within six months of treatment. Survival analyses accounting for competing events were performed. Among the 38020 patients included, 27608 (73%) were male and the median (IQR) age was 32 [25‒42] years. 26599 (70%) had bacteriologically confirmed TB while 11421 (30%) were clinically diagnosed. During 16531 person-years of follow-up, 2385 (6.3%, 95%CI 6.0‒6.5) and 1942 (5.1%, 95%CI 4.9‒5.3) patients were LTFU and died respectively. In the multivariable model, patients on re-treatment after LTFU or after failure and those previously treated compared to new TB patients were positively associated with LTFU. Patients coinfected with HIV and those with unknown HIV status were positively associated with LTFU. In contrast, females, clinically diagnosed, extra-pulmonary TB and older patients were negatively associated with LTFU. Patients HIV infected on ARVs, not on ARVs and unknown HIV status versus not infected were positively associated with mortality. Other comorbidities (not HIV), clinically diagnosed, undernourished and older patients were positively associated with mortality. More than 10% of TB patients either die or are LTFU before completing treatment. TB patients on re-treatment, HIV infected, clinically diagnosed, undernourished and the elderly needs more targeted interventions to improve survival and successfully treatment.