Comparison 1. Silicone gel versus no treatment (control).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Development of abnormal scarring ‐ prevention	5	402	Risk Ratio (M‐H, Random, 95% CI)	0.55 [0.21, 1.45]
1.1 High risk of scarring	2	51	Risk Ratio (M‐H, Random, 95% CI)	0.46 [0.21, 0.98]
1.2 Low risk of scarring	1	31	Risk Ratio (M‐H, Random, 95% CI)	0.35 [0.02, 8.08]
1.3 Risk not stated	3	320	Risk Ratio (M‐H, Random, 95% CI)	0.57 [0.10, 3.40]
2 Development of complications ‐ prevention	2	350	Risk Ratio (M‐H, Fixed, 95% CI)	8.0 [1.02, 62.83]
2.1 Prevention	2	350	Risk Ratio (M‐H, Fixed, 95% CI)	8.0 [1.02, 62.83]
3 Reduction of scar length ‐ treatment	1	27	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
4 Reduction in scar width ‐ treatment	1	27	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
5 Scar thickness ‐ treatment	2	77	Mean Difference (IV, Fixed, 95% CI)	0.00 [‐2.14, ‐1.85]
6 Scar pliability ‐ treatment	2	68	Mean Difference (IV, Fixed, 95% CI)	‐0.74 [‐0.83, ‐0.64]
7 Reduction of keloid scar size by 50% ‐ treatment	1	34	Risk Ratio (M‐H, Fixed, 95% CI)	5.0 [0.26, 97.00]
8 Scar colour amelioration ‐ treatment	5	151	Risk Ratio (M‐H, Fixed, 95% CI)	3.49 [1.97, 6.15]
9 Improvement in scar elasticity ‐ treatment	5	154	Risk Ratio (M‐H, Random, 95% CI)	3.03 [1.02, 8.99]
10 Symptomatic relief of itching and pain ‐ treatment	3	97	Risk Ratio (M‐H, Random, 95% CI)	1.23 [0.78, 1.96]
11 Development of complications ‐ treatment	2	39	Risk Ratio (M‐H, Fixed, 95% CI)	9.52 [1.35, 67.10]