However, we could not perform propensity matching for this characteristic, given the effect on the sample size (matching would have produced 28 matched pairs, severely reducing power), and we could not adjust for CD4 in the HIV outcome analysis (Table 5) because of limited power (only one person in the Nix-TB cohort had an unfavourable outcome with a CD4 < 200 cells/mm3). Here, CD4 is linked to tuberculosis.