Heterogeneity was explored using Q-test and the quantity of heterogeneity was measured by the I2 statistic (Figs 2–4). Fig 2. shows a substantial heterogeneity (I2 = 76.8%, P<0.001) among studies addressing the association between AUD and suicidal ideation. Fig 3. indicates a considerable heterogeneity (I2 = 88.5%, P<0.001) among studies addressing the association between AUD and suicide attempt. As shown in Fig 4, there was no evidence of heterogeneity (I2 = 0.0%, P = 0.521) across studies reporting OR estimates of AUD related completed suicide, but there was a moderate heterogeneity (I2 = 66.0%, P = 0.012) among the studies reporting RR.
