Fig. 4

Forest plot and funnel plot of incidence studies included in analysis. a 39 studies [15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53] and their incidence statistics are listed individually. The summary rate, calculated with meta-analysis and random-effects modelling, is listed on the final row. b 39 logit-transformed incidence figures are plotted against their individual standard errors