The multivariate model was constructed based on literature review and exploratory data analysis, and included factors known to be associated with OLD (age, smoking, TB), markers of HIV disease (CD4 cell count, viral load, ART), variables that were significant at the p<0.10 level in univariate analysis (CRP level, SHS) and potential confounders (sex, education, BMI). Here, CD4 is linked to tuberculosis.