Table 6. Results of subgroup analyses for seroma and chronic wound pain.

All outcomes are stratified according to study design (RCTs or observational), mesh location (onlay, retrorectus, preperitoneal, and intraperitoneal), mean BMI (<40 and >40), and study population (bariatric, neoplastic, vascular, and mixed). The value of I² shows the heterogeneity among subgroups.

P_subgroup represents p-values between subgroups.

IH, incisional hernia; OR, odds ratio; No Sig. Diff., no significant difference; Sig. Diff, significant difference

†- Significant difference was found between the mixed group with the bariatric (p=0.01), neoplastic (p=0.02), and vascular (p=0.008) groups.

Subgroups	Seroma					Chronic wound pain
	N studies	I2 (%)	OR [95% CI]	Psubgroup	Comments	N studies	I2 (%)	OR [95% CI]	Psubgroup	Comments
Study design
RCT	12	10	1.83 [1.15, 2.91]	0.77	No Sig. Diff.	5	0	1.63 [0.98, 2.71]	0.22	No Sig. Diff.
Observational	7	37	1.57 [0.63, 3.92]			1	-	12.65 [0.48, 331.08]
Mesh location
Onlay	9	40	1.85 [0.89, 3.87]	0.29	No Sig. Diff.	2	0	7.92 [0.85, 73.96]	0.36	No Sig. Diff.
Retrorectus	4	0	1.43 [0.74, 2.78]			1	-	1.04 [0.06, 16.98]
Preperitoneal	4	40	2.88 [0.94, 8.84]			2	0	1.83 [1.03, 3.28]
Intraperitoneal	2	0	0.57 [0.16, 2.07]			1	-	0.86 [0.25, 2.94]
Mean BMI
<40	7	16	1.23 [0.59, 2.57]	0.26	No Sig. Diff.	2	0	0.88 [0.29, 2.73]	0.29	No Sig. Diff.
>40	7	43	2.31 [1.01, 5.28]			2	28	2.38 [0.57, 9.97]
Study population
Bariatric	7	40	2.39 [1.06, 5.38]	0.04†	Sig. Diff.	3	12	2.34 [0.90, 6.05]	0.69	No Sig. Diff.
Neoplastic	4	0	2.06 [1.06, 4.00]			0	-	-
Vascular	4	0	2.57 [1.18, 5.64]			1	-	1.04 [0.06, 16.98]
Mixed	4	0	0.47 [0.17, 1.27]			2	15	1.22 [0.30, 5.00]