Comparison 1. LNG‐IUS with endometrial surveillance versus endometrial surveillance alone.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Endometrial Polyps	4		Peto Odds Ratio (Peto, Fixed, 95% CI)	Subtotals only
1.1 Short term follow‐up (12 months)	2	212	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.22 [0.08, 0.64]
1.2 Long term follow‐up (24 to 60 months)	4	417	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.22 [0.13, 0.39]
2 Endometrial Hyperplasia	4	417	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.13 [0.03, 0.67]
3 Endometrial Cancer	2	154	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Fibroids	3	314	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.48 [0.16, 1.46]
5 Abnormal Vaginal Bleeding or Spotting	3		Peto Odds Ratio (Peto, Fixed, 95% CI)	Subtotals only
5.1 12 months	3	376	Peto Odds Ratio (Peto, Fixed, 95% CI)	7.26 [3.37, 15.66]
5.2 24 months	2	233	Peto Odds Ratio (Peto, Fixed, 95% CI)	2.72 [1.04, 7.10]
5.3 45 months	1	100	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
5.4 60 months	1	94	Peto Odds Ratio (Peto, Fixed, 95% CI)	0.0 [0.0, 0.0]
6 Breast Cancer Recurrence	2	154	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.74 [0.64, 4.74]
7 Breast Cancer‐related Death	3	277	Peto Odds Ratio (Peto, Fixed, 95% CI)	1.02 [0.36, 2.84]