From Diagnosis to Recurrence-Free Survival - the Care Cascade for Tuberculosis Disease among People Detected by Active and Passive Case Finding in Central India: A Prospective Cohort Study

Background: Routine tuberculosis (TB) programmatic indicators fail to capture long-term outcomes like TB recurrence and mortality, given limited post-treatment follow-up. Furthermore, active case finding (ACF) has expanded in India, although its impact on long-term outcomes remains unclear. We assessed the TB care cascade in central India through one-year post-treatment and examined differences by case-finding strategy. Methods: From 2020 to 2022, we conducted a prospective cohort study of adults (≥18 years old) with drug-susceptible smear-positive pulmonary TB diagnosed by ACF or passive case finding (PCF) in five districts in central India. Participants were followed from diagnosis through one-year post-treatment. Composite unfavourable outcomes comprised pretreatment loss to follow-up, unsuccessful on-treatment outcomes, and post-treatment TB recurrence or death. Poisson regression was performed, accounting for complex survey design, with multiple imputation for missing data. Findings: Among 657 participants, 47.6% experienced composite unfavourable outcomes across the care cascade. Among those who completed treatment (n=447), 23.2% experienced post-treatment TB recurrence/death. Composite outcomes did not differ by case-finding strategy (adjusted risk ratio [aRR] 0.89 [0.76-1.03]). However, ACF-detected individuals had higher unsuccessful on-treatment outcomes (aRR 1.24 [95%CI: 1.02-1.55]), but lower post-treatment recurrence or death (aRR 0.61 [95%CI:0.43-0.86]). Severe undernutrition, unhealthy alcohol use, rural residence, lower educational attainment, and lack of cellphone access were independently associated with composite unfavourable outcomes. Interpretation: Nearly half of people experienced composite unfavourable outcomes across the care cascade. One-fourth experienced post-treatment recurrence or death, underscoring the need for systematic post-treatment follow-up. More intensive interventions may be needed to retain ACF-detected individuals during TB treatment.