Use of Rifampin Compared with Isoniazid for the Treatment of Latent Tuberculosis Infection in Japan: A Bayesian Inference with Markov Chain Monte Carlo Method.

Objective Treating latent tuberculosis infection (LTBI) is essential for eliminating the serious endemicity of tuberculosis. A shorter regimen is preferred to longer regimens because the former has better adherence with a better safety profile. However, lengthy treatment with isoniazid is still recommended in Japan. Based on the latest evidence, we switched from a conventional nine-month isoniazid regimen to a shorter four-month rifampin regimen for the treatment of LTBI. Methods To evaluate the safety and efficacy of the shorter regimen, we conducted Bayesian analyses using a stochastic mathematical model to calculate the posterior probabilities of several parameters. Patients Clinical data of 13 patients in the isoniazid group and 5 in the rifampin group were used for the Bayesian analyses. The outcomes measured were completion of the treatment, adverse effects, number of clinic visits, and medical costs. Results The medial posterior probability of the isoniazid group completing the treatment was 66% [95% credible interval (CrI) 43-89%], whereas that of the rifampin group was 86% (95% CrI 60-100%). The probability that the completion rate in the rifampin group was better than that in the isoniazid group was as high as 88% (95% CrI 0-100%). Other parameters, such as the number of clinical visits and duration of treatment, were better with rifampin therapy than with isoniazid therapy, with comparable medical costs. Conclusion Four months of rifampin therapy might be preferred to isoniazid for treating LTBI in Japan.