While rifampin is a more costly tuberculosis treatment, its shorter treatment length and fewer adverse events resulted in a lower total cost across study sites.
Isoniazid, an inhibitor of mycobacteria cell wall synthesis, is the standard of treatment of latent TB. Rifampin, a more costly medication, is generally reserved for active TB treatment along with ethambutol and pyrazinamide.
This study by researchers at State University of Rio de Janeiro, McGill University, Universtitas Padjadjaran – Indonesia, Korean National Tuberculosis Association, and Centre National Hospitalier Universitaire de Pneumo-Phtisiologie – Benin, demonstrated that while rifampin is more expensive, its shorter treatment length and fewer adverse events resulted in a lower total cost across study sites.
Ultimately this represented a cost savings to the health system of roughly one-third of the cost of isoniazid. The study’s applicability was strengthened by its multi-centred approach that included representative countries across GDP.
The failure to include individual cost burden limited the study’s ability to fully account for possible barriers to treatment.
Background: Four months of rifampin treatment for latent tuberculosis infection is safer, has superior treatment completion rates, and is as effective as 9 months of isoniazid. However, daily medication costs are higher for a 4-month rifampin regimen than a 9-month isoniazid regimen.
Objective: To compare health care use and associated costs of 4 months of rifampin and 9 months of isoniazid.
Design: Health system cost comparison using all health care activities recorded during 2 randomized clinical trials. (ClinicalTrials.gov: NCT00931736 and NCT00170209)
Setting: High-income countries (Australia, Canada, Saudi Arabia, and South Korea), middle-income countries (Brazil and Indonesia), and African countries (Benin, Ghana, and Guinea).
Participants: Adults and children with clinical or epidemiologic factors associated with increased risk for developing tuberculosis that warranted treatment for latent tuberculosis infection.
Measurements: Health system costs per participant.
Results: A total of 6012 adults and 829 children were included. In both adults and children, greater health system use and higher costs were observed with 9 months of isoniazid than with 4 months of rifampin. In adults, the ratios of costs of 4 months of rifampin versus 9 months of isoniazid were 0.76 (95% CI, 0.70 to 0.82) in high-income countries, 0.90 (CI, 0.85 to 0.96) in middle-income countries, and 0.80 (CI, 0.78 to 0.81) in African countries. Similar findings were observed in the pediatric population.
Limitation: Costs may have been overestimated because the trial protocol required a minimum number of follow-up visits, although fewer than recommended by many authoritative guidelines.
Conclusion: A 4-month rifampin regimen was safer and less expensive than 9 months of isoniazid in all settings. This regimen could be adopted by tuberculosis programs in many countries as first-line therapy for latent tuberculosis infection.
Primary Funding Source: Canadian Institutes of Health Research.
Mayara Lisboa Bastos, Jonathon R Campbell, Olivia Oxlade, Menonli Adjobimey, Anete Trajman, Rovina Ruslami, Hee Jin Kim, Joseph Obeng Baah, Brett G Toelle, Richard Long, Vernon Hoeppner, Kevin Elwood, Hamdan Al-Jahdali, Lika Apriani, Andrea Benedetti, Kevin Schwartzman, Dick Menzies