The likelihood of second-line ART failure for patients with CD4 count below 100 cells/mm3 at the start of second-line ART was 3.8 times (AHR = 3.79, 95% CI = 1.61–8.91) higher compared to patients who started second-line ART at CD4 count of 100 cells/mm3 or above after controlling for the effect of age, TB status, WHO stage and adherence. Here, CD4 is linked to tuberculosis.