Table of Contents
International Scholarly Research Notices
Volume 2014, Article ID 704980, 5 pages
Clinical Study

Optimal Duration of Daily Antituberculosis Therapy before Switching to DOTS Intermittent Therapy to Reduce Mortality in HIV Infected Patients: A Duration-Response Analysis Using Restricted Cubic Splines

Department of Infectious Diseases, Rural Development Trust Hospital, Kadiri Road, Bathalapalli, Anantapur, Andhra Pradesh 515661, India

Received 11 June 2014; Revised 28 November 2014; Accepted 29 November 2014; Published 16 December 2014

Academic Editor: Roja Rahimi

Copyright © 2014 Gerardo Alvarez-Uria et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Compared with thrice-weekly intermittent antituberculosis therapy (ATT), the use of daily ATT during the intensive phase has shown improved survival in HIV infected patients with tuberculosis. However, the optimal duration of daily ATT before initiating intermittent ATT is not well known. In this study, we analysed the mortality of HIV-related tuberculosis according to the duration of daily ATT before switching to thrice-weekly ATT in patients who completed at least two months of treatment in an HIV cohort study. Statistical analysis was performed using Cox proportional hazard models. To relax the linearity assumption in regression models and to allow for a flexible interpretation of the relationship between duration of daily ATT and mortality, continuous variables were modelled using restricted cubic splines. The study included 520 HIV infected patients with tuberculosis and 8,724.3 person-months of follow-up. The multivariable analysis showed that the mortality risk was inversely correlated with the duration of daily ATT before switching to intermittent therapy during the first 30 days of ATT but, after approximately 30 days of treatment, differences were not statistically significant. The results of this study suggest that daily ATT should be given for at least 30 days before switching to intermittent ATT in HIV infected patients with tuberculosis.