Hidden in Success: Gendered Patterns of Suboptimal Care Engagement Among TB Patients Who "Successfully" Completed Treatment in South Africa

Background: Timeously completing tuberculosis (TB) treatment is key to optimal health outcomes. Suboptimal treatment refill patterns, even among those categorized as “treatment success,” may portend unfavorable outcomes.

Methods: Using patient-level medication refill data, latent-class mixed modelling was used to identify longitudinal trajectories of care engagement among TB patients achieving programmatic treatment success. Logistic regression was conducted to investigate participant-level characteristics associated with trajectory class membership.

Results: Among 548 participants, we identified three trajectories: Class 1 (consistent engagement; 84.1%), Class 2 (suboptimal engagement after 2 months; 7.7%) and Class 3 (suboptimal engagement from initiation; 8.2%). At treatment completion, Classes 1-3 accumulated 9.7 (95% CI: 7.4-11.8), 68.4 (60.4-76.9) and 55.5 (48.1-62.7) missed refill days, respectively. In gender-stratified models, men exhibited all three trajectories (83.1%, 7.4%, and 9.5%, respectively), and accumulated 10.6 [7.8-13.3], 61.0 [50.2-71.3], 62.31 [53.14-71.72] missed refill days, respectively. Women exhibited only Classes 1 and 3 (89.5% and 10.5%, respectively) and accumulated 12.1 [7.8-16.5] and 46.9 [33.3-61.6] missed refill days, respectively. Among men, prior TB (Class 2: aOR 7.44, 2.79-19.8; Class 3: aOR 2.78, 1.07-7.25) and HIV-negative status (Class 3: aOR 2.72, 1.13-6.54) were associated with suboptimal trajectories. Among women, prior TB was associated with suboptimal engagement (aOR 5.22, 1.11-24.44).

Conclusion: Programmatic “treatment success” obscured heterogeneity in treatment refill patterns. Patient-centered counseling and gender-responsive interventions are needed to address treatment refill behaviors. Shorter regimens alone may not resolve suboptimal engagement, highlighting the need for flexible treatment strategies.