Figure 1From: Problem drinking as a risk factor for tuberculosis: a propensity score matched analysis of a national survey Standardised percent bias in the distribution of potential confounders of the association between problem drinking and TB in the South-African adult population. Pre- and post-matching differences in the prevalence of each potential confounder between problem drinkers and moderate drinkers/abstainers as a percentage of the square root of the average of their variances. For definition of variables, see text.Back to article page