Papers

Impact of DOTS compared with DOTS-plus on multidrug resistant tuberculosis and tuberculosis deaths: decision analysis

Timothy R Sterling, associate professor of medicine and epidemiology, ^a Harold P Lehmann, associate professor, ^b Thomas R Frieden, commissioner of health. ^c

^a Johns Hopkins University Center for Tuberculosis Research, 424 N Bond Street, Baltimore, MD 21231, USA, ^b Department of Health Sciences Information, Johns Hopkins University School of Medicine, 2024 E Monument Street, Baltimore, MD 21287-0007, ^c New York City Department of Health, 125 Worth Street, New York, NY 10013, USA

Correspondence to: T R Sterling
tsterls{at}jhmi.edu

Objective: This study sought to determine the impact of the World Health Organization's directly observed treatment strategy (DOTS) compared with that of DOTS-plus on tuberculosis deaths, mainly in the developing world.
Design: Decision analysis with Monte Carlo simulation of a Markov decision tree.
Data sources: People with smear positive pulmonary tuberculosis.
Data analysis: Analyses modelled different levels of programme effectiveness of DOTS and DOTS-plus, and high (10%) and intermediate (3%) proportions of primary multidrug resistant tuberculosis, while accounting for exogenous reinfection.
Main outcome measure: The cumulative number of tuberculosis deaths per 100 000 population over 10 years.
Results: The model predicted that under DOTS, 276 people would die from tuberculosis (24 multidrug resistant and 252 not multidrug resistant) over 10 years under optimal implementation in an area with 3% primary multidrug resistant tuberculosis. Optimal implementation of DOTS-plus would result in four (1.5%) fewer deaths. If implementation of DOTS-plus were to result in a decrease of just 5% in the effectiveness of DOTS, 16% more people would die with tuberculosis than under DOTS alone. In an area with 10% primary multidrug resistant tuberculosis, 10% fewer deaths would occur under optimal DOTS-plus than under optimal DOTS, but 16% more deaths would occur if implementation of DOTS-plus were to result in a 5% decrease in the effectiveness of DOTS
Conclusions: Under optimal implementation, fewer tuberculosis deaths would occur under DOTS-plus than under DOTS. If, however, implementation of DOTS-plus were associated with even minimal decreases in the effectiveness of treatment, substantially more patients would die than under DOTS.

What is already known on this topic DOTS is an effective, albeit underused, strategy for treating tuberculosis DOTS may be insufficiently effective in treating multidrug resistant tuberculosis The use of toxic reserve drugs (DOTS-plus) is an effective but costly strategy for treating multidrug resistant tuberculosis The impact of the implementation of DOTS-plus on overall tuberculosis control is unknown What this study adds If implementation of DOTS-plus is associated with even minimal decreases in the effectiveness of DOTS, more patients would die with tuberculosis under DOTS-plus than under DOTS alone If DOTS-plus is implemented, it must not divert resources from and decrease the effectiveness of DOTS