We read with interest the meta-analysis by Medea Gegia and colleagues that reviewed treatment outcomes of isoniazid-resistant tuberculosis when treated with first-line drugs. The authors reviewed all studies published before March, 2015, and focused on the effect of isoniazid monoresistance on microbiological outcomes of tuberculosis treatment. The study found that failure, relapse, and acquired drug resistance were more frequent among patients infected with isoniazid-resistant Mycobacterium tuberculosis. Deaths on tuberculosis treatment were not reported, because the analysis was per-protocol and aimed to report objective microbiological endpoints...