“…There was a high level of heterogeneity (I 2 =80%, τ 2 =0.40, χ 2 =49.39, df=10, p<0.00001; figure 3A). To investigate whether the presence of outliers could have contributed to the overall significance, we excluded two studies 30 33. However, the pooled SMD in pain between the groups remained significant (−0.36, 95% CI −0.64 to −0.09, p=0.009) with a low-to-moderate level of heterogeneity (I 2 =42%, τ 2 =0.07, χ 2 =13.87, df=8, p=0.09).…”