Muysoms 2013.

Study characteristics
Methods	Randomised controlled trial Location International multicenter, Spain and Belgium Study dates  Between December 2004 and July 2008
Participants	Inclusion/exclusion criteria Primary and incisional ventral hernias. Parastomal hernias and all hernias close to bony structures, like suprapubic, subxiphoidal, subcostal hernias, and lumbar hernias were excluded Patient characteristics (nonabsorbable tacks with nonabsorbable sutures (43) / nonabsorbable tacks only (33)) Age (mean, SD): 56.7 (16.2) / 59.8 (9.4) Gender (male, %): 52 / 59 BMI (kg/m2, mean, range): 29.6 (6.5) / 29.3 (4.7) Hernia type (incisional, %): 72 / 78 Hernia size (mean, SD, cm2): 45.6 (50.6) / 46.5 (55.4) Comorbidity: NR
Interventions	Intervention/control: nonabsorbable tacks (1 – 2 cm distance) with nonabsorbable sutures compared to nonabsorbable tacks (double crown, 1 – 2 cm distance) Mesh: different meshes in the centres Intra‐abdominal mesh position: intra‐peritoneal Surgical approach: laparoscopic
Outcomes	Recurrence (follow‐up 2 years), pain (primary outcome), return to activity, local infection, seroma, haematoma, length of hospital stay, duration of surgery
Notes	Funding source(as originally reported) This study was performed with a research grant from WL Gore & Ass, Flagstaff, USA Declarations of interest for the primary investigators (as originally reported) The co‐authors declare no conflict of interest. Data for sensitivity analyses Randomised: 43/33 Analysed: 36/27 Imputed in ITT sensitivity analysis: 7/6
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	MS Excel random function
Allocation concealment (selection bias)	Low risk	Allocation of a specific participant was sent to the surgeon after receiving the informed consent
Blinding of participants and personnel (performance bias) All outcomes	High risk	Surgeon not blinded. Other caregivers and participants unclear
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported. Tendentially recurrence "lower risk" (objective outcome), pain "higher risk" (subjective outcome)
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not all randomised participants analysed. No information on reasons for dropout
Selective reporting (reporting bias)	Low risk	The study protocol is not available but it seems that the published reports include all expected outcomes, including those that were prespecified
Other bias	Low risk	None detected