Research article
Factors associated with mortality in patients with drug-susceptible pulmonary tuberculosis
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* Corresponding author: Payam Nahid pnahid@ucsf.edu
1 Curry International Tuberculosis Center, University of California, San Francisco, CA, USA
2 The Tuberculosis Control Section, Department of Public Health, San Francisco, CA, USA
3 New York University, New York, NY, USA
4 University of California, Los Angeles, USA
5 Division of Mycobacterial and Respiratory Infections, National Jewish Health, Denver, CO, USA
BMC Infectious Diseases 2011, 11:1 doi:10.1186/1471-2334-11-1
Published: 3 January 2011Abstract
Background
Tuberculosis is a leading cause of death worldwide, yet the determinants of death are not well understood. We sought to determine risk factors for mortality during treatment of drug-susceptible pulmonary tuberculosis under program settings.
Methods
Retrospective chart review of patients with drug-susceptible tuberculosis reported to the San Francisco Tuberculosis Control Program from 1990-2001.
Results
Of 565 patients meeting eligibility criteria, 37 (6.6%) died during the study period. Of 37 deaths, 12 (32.4%) had tuberculosis listed as a contributing factor. In multivariate analysis controlling for follow-up time, four characteristics were independently associated with mortality: HIV co-infection (HR = 2.57, p = 0.02), older age at tuberculosis diagnosis (HR = 1.52 per 10 years, p = 0.001); initial sputum smear positive for acid fast bacilli (HR = 3.07, p = 0.004); and experiencing an interruption in tuberculosis therapy (HR = 3.15, p = 0.002). The association between treatment interruption and risk of death was due to non-adherence during the intensive phase of treatment (HR = 3.20, p = 0.001). The median duration of treatment interruption did not differ significantly in either intensive or continuation phases between those who died and survived (23 versus 18 days, and 37 versus 29 days, respectively). No deaths were directly attributed to adverse drug reactions.
Conclusions
In addition to advanced age, HIV and characteristics of advanced tuberculosis, experiencing an interruption in anti-tuberculosis therapy, primarily due to non-adherence, was also independently associated with increased risk of death. Improving adherence early during treatment for tuberculosis may both improve tuberculosis outcomes as well as decrease mortality.