Overall risk of Infection in patients suffering from haemophilia.

<p>Study or Subgroup on the Y-axis refers to first author and publication year; events refers to the number of patients who suffered post operative surgical site infections while total refers to the number of patients in that group. Weight refers to influence of each study on overall estimate (weights are from fixed effect analyses); for each study the central square indicates risk ratio, line represents 95% confidence interval (CI), and the size of the square reflects the study's weight in the pooling; overall estimate refers to pooled estimate of risk ratio after mathematical combination of all studies; the X-axis indicates the scale and the direction of the effect of HIV status on the risk of post operative surgical site infection. I-squared denotes the extent of heterogeneity in study outcomes, with a (hypothetical) value of 100% meaning considerable heterogeneity and 0% meaning no heterogeneity between studies.