Comparison 1. Knowledge.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Knowledge ‐ all studies	52	13316	Mean Difference (IV, Random, 95% CI)	13.27 [11.32, 15.23]
2 Knowledge ‐ subgroup by timing of intervention (in consultation versus in preparation for consultation)	52		Mean Difference (IV, Random, 95% CI)	Subtotals only
2.1 In consultation	8	922	Mean Difference (IV, Random, 95% CI)	10.57 [4.79, 16.36]
2.2 In preparation for consultation	44	12394	Mean Difference (IV, Random, 95% CI)	13.77 [11.61, 15.93]
3 Knowledge ‐ studies without high risk of bias	47	12327	Mean Difference (IV, Random, 95% CI)	13.43 [11.37, 15.49]