Mortality benefit of isoniazid preventive therapy in HIV-positive persons: a simulation study.

A meta-analysis of isoniazid preventive therapy (IPT) in human immunodeficiency virus-positive individuals failed to show a mortality benefit even though tuberculosis is a leading cause of death in this group. Results for purified protein derivative (PPD) positive patients were heterogeneous, however, and two of the included trials had many PPD-unknowns. When all PPD-unknowns were allocated to either PPD-positive or PPD-negative, the individual trial results were not robust, and simulated meta-analyses showed an overall reduction in all-cause mortality for PPD-positive individuals on IPT (relative risk 0.76; 95% credibility interval 0.6-0.95).