Hidden gaps in TB care revealed among patients who 'completed' treatment

Tuberculosis treatment depends on patients taking their medicines regularly, but the usual way health programs report outcomes can hide important differences in how people actually stay in care. Andrew Medina‐Marino and colleagues set out to look behind the simple label of “treatment success” in South Africa. They asked whether some people who are officially recorded as having completed treatment nevertheless followed the treatment schedule poorly at certain times. To do this, the researchers used patient-level medication refill data — the records showing when people picked up their pills — to track patterns of engagement through the course of therapy. By looking at refill behavior over time for hundreds of patients, they hoped to find distinct trajectories of care that a single success number would miss. The study focuses on who falls into these different patterns and when missed refills tend to cluster, aiming to highlight where additional support or different strategies might be needed even after a program declares treatment successful.

The team analyzed data from 548 participants using latent-class growth modelling to identify groups with similar refill patterns over time, and used logistic regression to examine which participant characteristics were linked to each pattern. They found 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%). By the time treatment finished, participants in Classes 1-3 had 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 showed all three trajectories (83.1%, 7.4%, and 9.5%) and accumulated 10.6 [7.8-13.3], 61.0 [50.2-71.3], 53.3 [53.3-71.4] missed refill days, respectively. Women showed only Classes 1 and 3 (89.5% and 10.5%) and accumulated 12.1 [7.8-16.5] and 46.9 [33.3-61.6] missed refill days. Associations included prior TB and HIV status: among men, prior TB was linked to Class 2 (aOR 7.44, 2.79-19.8) and Class 3 (aOR 2.78, 1.07-7.25), and HIV-negative status was linked to Class 3 (aOR 2.72, 1.13-6.54). Among women, prior TB was associated with suboptimal engagement (aOR 5.22, 1.11-24.44).

These findings show that a programmatic label of success can conceal people who struggle at specific stages of treatment. Even when the overall outcome is marked as treatment completion, many patients accumulated dozens of missed refill days, and these patterns differed by gender and past TB history. The study argues for patient-centered counseling that recognizes when a person is at risk of falling off track — for example after two months or right from the start — and for gender-responsive interventions that reflect the different patterns seen in men and women. The researchers also note that simply shortening treatment will probably not fix these engagement problems, and they emphasize the value of “regimen forgiveness” — treatments that tolerate some missed doses without losing effectiveness. In short, program managers should look beyond the headline success rate, use refill data to spot at-risk groups, and tailor support so that completion really means continuous, effective care.