Comparison 8. Sensitivity analysis: inclusion of missing data, assuming loss to follow‐up did not have developed incisional hernia.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Absorbable versus non‐absorbable (hernia)	16	5560	Risk Ratio (M‐H, Random, 95% CI)	1.08 [0.92, 1.28]
1.1 Same closure technique and method in each group	14	5257	Risk Ratio (M‐H, Random, 95% CI)	1.13 [0.95, 1.35]
1.2 Different closure technique or method in each group	2	303	Risk Ratio (M‐H, Random, 95% CI)	0.54 [0.27, 1.05]
2 Mass versus layered closure (hernia)	5	1220	Risk Ratio (M‐H, Random, 95% CI)	1.80 [0.57, 5.62]
2.1 Same closure technique and suture material in each group	1	206	Risk Ratio (M‐H, Random, 95% CI)	3.86 [1.34, 11.07]
2.2 Different closure technique or suture material in each group	4	1014	Risk Ratio (M‐H, Random, 95% CI)	1.29 [0.34, 4.92]
3 Continuous versus interrupted	11	4046	Risk Ratio (M‐H, Random, 95% CI)	1.01 [0.76, 1.34]
3.1 Same closure method and suture material in each group	4	1363	Risk Ratio (M‐H, Random, 95% CI)	1.18 [0.87, 1.61]
3.2 Different closure method or suture material in each group	7	2683	Risk Ratio (M‐H, Random, 95% CI)	0.94 [0.60, 1.48]
4 Monofilament versus multifilament (hernia)	16	4981	Risk Ratio (M‐H, Random, 95% CI)	0.76 [0.60, 0.97]
4.1 Same closure technique and method	10	2982	Risk Ratio (M‐H, Random, 95% CI)	0.80 [0.56, 1.14]
4.2 Different closure technique or method	6	1999	Risk Ratio (M‐H, Random, 95% CI)	0.74 [0.50, 1.08]
5 Slow absorbable versus fast absorbable (hernia)	9	3877	Risk Ratio (M‐H, Random, 95% CI)	0.82 [0.62, 1.08]
5.1 Same closure method and technique	5	1863	Risk Ratio (M‐H, Random, 95% CI)	0.88 [0.53, 1.45]
5.2 Different closure method or technique	4	2014	Risk Ratio (M‐H, Random, 95% CI)	0.79 [0.56, 1.12]