title: The effect of tuberculosis on mortality in HIV positive people: a meta-analysis.
abstract: BACKGROUND
  Tuberculosis is a leading cause of death in people living with HIV (PLWH). We conducted a meta analysis to assess the effect of tuberculosis on mortality in people living with HIV.
  
  
  METHODS
  Meta-analysis of cohort studies assessing the effect of tuberculosis on mortality in PLWH. To identify eligible studies we systematically searched electronic databases (until December 2008), performed manual searches of citations from relevant articles, and reviewed conference proceedings. Multivariate hazard ratios (HR) of mortality in PLWH with and without tuberculosis, estimated in individual cohort studies, were pooled using random effect weighting according to "Der Simonian Laird method" if the p-value of the heterogeneity test was <0.05.
  
  
  RESULTS
  Fifteen cohort studies were systematically retrieved. Pooled overall analysis of these 15 studies estimating the effect of tuberculosis on mortality in PLWH showed a Hazard Ratio (HR) of 1.8 (95% confidence interval (CI): 1.4-2.3). Subanalysis of 8 studies in which the cohort was not exposed to highly active antiretroviral therapy (HAART) showed an HR of 2.6 (95% CI: 1.8-3.6). Subanalysis of 6 studies showed that tuberculosis did not show an effect on mortality in PLWH exposed to HAART: HR 1.1 (95% CI: 0.9-1.3).
  
  
  CONCLUSIONS
  These results provide an indication of the magnitude of benefit to an individual that could have been expected if tuberculosis had been prevented. It emphasizes the need for additional studies assessing the effect of preventing tuberculosis or early diagnosis and treatment of tuberculosis in PLWH on reducing mortality. Furthermore, the results of the subgroup analyses in cohorts largely exposed to HAART provide additional support to WHO's revised guidelines, which include promoting the initiation of HAART for PLWH co-infected with tuberculosis. The causal effect of tuberculosis on mortality in PLWH exposed to HAART needs to be further evaluated once the results of more cohort studies become available.
authors.affiliation: Unit Research, KNCV Tuberculosis Foundation, The Hague, The Netherlands. m.straetemans@kit.nl
authors.forename: Masja
authors.initials: M
authors.lastname: Straetemans
authors.forename: Ana L
authors.initials: AL
authors.lastname: Bierrenbach
authors.forename: Nico
authors.initials: N
authors.lastname: Nagelkerke
authors.forename: Philippe
authors.initials: P
authors.lastname: Glaziou
authors.forename: Marieke J
authors.initials: MJ
authors.lastname: van der Werf
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D023241:Antiretroviral Therapy, Highly Active / Q000379:methods; D015496:CD4-Positive T-Lymphocytes / Q000821:virology; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011786:Quality Control; D014376:Tuberculosis / Q000150:complications* / Q000401:mortality*