Fig. 8

Forest plot of cohort studies; sub-group analysis pooled effect size (HR) estimates of anemia for TB by participant age. The scale in the x-axis represents HR risk estimate of the studies. The hard line represents the odd ratio value showing no association (HR of 1). The dashed line represents the pooled point estimate of HR of anemia for the TB infection. The black dot at the center of the gray box represents the point HR estimate of each study, and the line indicates the 95% confidence interval of the estimates. The gray boxes represent the weight of each study contributing to the pooled HR estimate. The first two blue diamonds represent the 95% confidence interval for subgroup analysis pooled HR estimate, and the last blue diamond represents the 95% confidence interval for overall pooled HR estimate. HR hazard ratio, CI confidence interval, I² shows the heterogeneity of the included studies, p indicates the statistical significance of the heterogeneity, + anemia severity not defined, * mild anemia, @ mild and moderate anemia, # moderate anemia, $ severe anemia