Tuberculosis treatment discontinuation and symptom persistence: an observational study of Bihar, India's public care system covering >100,000,000 inhabitants

Abstract

Background: The effectiveness of India's TB control programs depend critically on patients completing appropriate treatment. Discontinuing treatment prior to completion can leave patients infectious and symptomatic. Developing strategies to reduce early discontinuation requires characterizing its patterns and their link to symptom persistence.

Methods: The 2011 BEST-TB survey (360 clusters, 11 districts) sampled patients (n = 1007) from Bihar's public healthcare system who had initiated treatment >6 months prior to being interviewed, administering questionnaires to patients about TB treatment duration and symptoms, prior treatment, and sociodemographic characteristics. Multivariate logistic regression models estimated the risk of treatment discontinuation for these characteristics. Similar models estimated probabilities of symptom persistence to 25 weeks post-treatment initiation adjusting for the same predictors and treatment duration. All models included district fixed effects, robust standard errors, and adjustments for the survey sampling design. Treatment default timing and symptom persistence relied solely on self-report.

Results: 24% of patients discontinued treatment prior to 25 weeks. Higher likelihood of discontinuation occurred in those who had failed to complete previous TB treatment episodes (aOR: 4.77 [95% CI: 1.98-11.53]) and those seeing multiple providers (3.67 per provider [1.94-6.95]). Symptoms persisted in 42% of patients discontinuing treatment within 5 weeks versus 28% for completing 25 weeks of treatment. Symptom persistence was more likely for those with prior TB treatment (aOR: 5.05 [1.90-13.38]); poorer patients (2.94 [1.51-5.72]); and women (1.79 [1.07-2.99]). Predictors for treatment discontinuation prior to 16 weeks were similar.

Conclusions: Premature TB treatment discontinuation and symptom persistence is particularly high among individuals who have failed to complete treatment for a prior episode. Strategies to identify and promote treatment completion in this group appear promising. Likewise, effective TB regimens of shortened duration currently in trials may eventually help to achieve higher treatment completion rates.

Figure 1

Map of regions surveyed within districts of Bihar (Inset map showing location of Bihar within India). The figure shows the map of Bihar and its districts. Gray areas represent the survey regions containing the 360 study clusters. Hashed areas represent survey regions with no TB patients eligible for study inclusion. The inset map of India shows the state of Bihar (Black) along with all other Indian states.

Figure 2

Cumulative risk of treatment default stratified by prior TB treatment and prior treatment completion. The figure shows the proportion of TB patients who have ended treatment during the first 25 weeks of treatment. In addition to showing the overall rate of treatment default (solid line), separate curves are shown for patients with no prior TB treatment episodes, patients with prior TB episodes where they completed prior treatment, and patients with prior TB episodes where they did not complete treatment.

Figure 3

Proportion of TB patients with symptoms persisting by time since treatment initiation. The figure shows the proportion of patients with any symptoms and with specific symptoms a given number of weeks after treatment initiation for all patients and stratified by patients with and without prior TB episodes.