CD4 and tuberculosis: In this analysis, including 331 tuberculosis episodes, occurring at median CD4+ cell count 299 cells/μl (IQR 170–489), ethnicity remained strongly associated with the risk of a tuberculosis event, with those of Black African origin having a higher risk of tuberculosis compared with those of Black Caribbean origin in both univariable and multivariable models [crude RR: 2.45 (1.40–4.27); adjusted RR: 2.10 (1.19–3.70)].