Group 1 studies
Fourteen studies36-45,47-53 reported as outcome the proportion of admissions attributed to ADRs. To estimate the summary proportion of admissions attributed to ADRs, we first pooled all group 1 studies and tested for heterogeneity. Since very high heterogeneity was found (I2 = 98.2%), no meta-analysis was performed. The median [IQR] proportion of admissions attributed to ADRs among the 14 studies was 4.8% [1.5% to 7.0%] (Figure 2).