Treatment Strategy for Rifampin-Susceptible Tuberculosis

BACKGROUND

Tuberculosis is usually treated with a 6-month rifampin-based regimen. Whether a strategy involving shorter initial treatment may lead to similar outcomes is unclear.

METHODS

In this adaptive, open-label, noninferiority trial, we randomly assigned participants with rifampin-susceptible pulmonary tuberculosis to undergo either standard treatment (rifampin and isoniazid for 24 weeks with pyrazinamide and ethambutol for the first 8 weeks) or a strategy involving initial treatment with an 8-week regimen, extended treatment for persistent clinical disease, monitoring after treatment, and retreatment for relapse. There were four strategy groups with different initial regimens; noninferiority was assessed in the two strategy groups with complete enrollment, which had initial regimens of high-dose rifampin-linezolid and bedaquiline-linezolid (each with isoniazid, pyrazinamide, and ethambutol). The primary outcome was a composite of death, ongoing treatment, or active disease at week 96. The noninferiority margin was 12 percentage points.

RESULTS

Of the 674 participants in the intention-to-treat population, 4 (0.6%) withdrew consent or were lost to follow-up. A primary-outcome event occurred in 7 of the 181 participants (3.9%) in the standard-treatment group, as compared with 21 of the 184 participants (11.4%) in the strategy group with an initial rifampin-linezolid regimen (adjusted difference, 7.4 percentage points; 97.5% confidence interval [CI], 1.7 to 13.2; noninferiority not met) and 11 of the 189 participants (5.8%) in the strategy group with an initial bedaquiline-linezolid regimen (adjusted difference, 0.8 percentage points; 97.5% CI, -3.4 to 5.1; noninferiority met). The mean total duration of treatment was 180 days in the standard-treatment group, 106 days in the rifampin-linezolid strategy group, and 85 days in the bedaquiline-linezolid strategy group. The incidences of grade 3 or 4 adverse events and serious adverse events were similar in the three groups.

CONCLUSIONS

A strategy involving initial treatment with an 8-week bedaquiline-linezolid regimen was noninferior to standard treatment for tuberculosis with respect to clinical outcomes. The strategy was associated with a shorter total duration of treatment and with no evident safety concerns. (Funded by the Singapore National Medical Research Council and others; TRUNCATE-TB ClinicalTrials.gov number, NCT03474198.).

Patient-cost survey for tuberculosis in the context of patient-pathway modelling

SETTING: Eight tuberculosis treatment sites in Cavite Province, the Philippines, including two sites specialising in management of multidrug-resistant tuberculosis (MDR-TB).OBJECTIVE: To evaluate costs incurred by TB patients and to determine the proportion of households that faced catastrophic costs, then to consider cost survey responses alongside results of detailed patient-pathway modelling.DESIGN: Clustered cross-sectional survey using a field testing version of the WHO TB patient-costing tool and protocol; face-to-face interviews with 194 patients conducted in May-August 2016. Costs included direct-medical, direct non-medical and indirect costs using the human capital approach. Patients were deemed to incur catastrophic expenditure if TB-related costs exceeded 20% of annual household income. Patient pathways were modelled following multiple health staff interviews.RESULTS: Estimated mean cost incurred by patients with drug-susceptible TB was US$321 vs. $2356 for MDR-TB patients. Catastrophic costs were suffered by 28% of drug-susceptible and 80% of MDR-TB patients, with lost income being the largest contributor. Patient-pathway modelling suggested most patients had under-reported health visits.CONCLUSION: Survey results indicate that patient costs are large for all patients in Cavite, particularly for MDR-TB patients. Patient-pathway modelling suggests these costs are an underestimate due to poor recollection of health visits, suggesting that the WHO instrument and protocol could be improved to better capture the diagnostic journey.