Comparison 9. A ‐ Data Collection Location and Method: Use of self‐sampling kits.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
9.1 Retention	1	19582	Risk Difference (M‐H, Random, 95% CI)	0.09 [0.04, 0.13]
9.1.1 Directly mailed self‐sampling kit vs invitation to order salf‐sampling kit	1	6529	Risk Difference (M‐H, Random, 95% CI)	0.07 [0.05, 0.09]
9.1.2 Directly mailed self‐sampling kit vs usual follow up	1	6527	Risk Difference (M‐H, Random, 95% CI)	0.13 [0.11, 0.15]
9.1.3 Invitation to order self‐sampling vs usual follow up	1	6526	Risk Difference (M‐H, Random, 95% CI)	0.06 [0.04, 0.08]