Lavand'homme 2007.

Methods	Triple‐blinded (participants, provider, outcome assessor), placebo/sham‐controlled, randomized clinical trial Sequence generation by computer‐generated random numbers Follow‐up: 6 months
Participants	Participants: 92 adults in a university setting in Brussels, Belgium Operation: elective caesarean section (Pfannenstiel incision) 3 groups, size: 30/30/30 Age (group 1, 2, 3): 33 years (SD ± 5), 31 (SD ± 5), 31 (SD ± 6) Men/women: 0/92 Remarks: no previous caesarean delivery
Interventions	Group 1 (ropivacaine): spinal bupivacaine (1.8‐2 mL hyperbaric 0.5%, sufentanil 1 µg/kg), post‐op for 48 h continuous wound irrigation (ropivacaine (0.2%, 5 mL/h), every 12 h diclofenac (75 mg in 50 mL/20 min)), PCA (morphine, no basal rate, demand 1 mg, lockout 5 min, max 25 mg/4 h), as needed paracetamol (1 g/6 h) Group 2 (diclofenac): spinal bupivacaine (1.8 mL‐2 mL hyperbaric 0.5%, sufentanil 1 µg/kg), post‐op for 48 h continuous wound irrigation (diclofenac (300 mg in 240 mL, 5 mL/h) IV saline 50 mL/20 min every 12 h), PCA (morphine, no basal rate, demand 1 mg, lockout 5 min, max 25 mg/4 h), as needed paracetamol (1 g/6 h) Group 3 (saline): spinal bupivacaine (1.8 mL to 2 mL hyperbaric 0.5%, sufentanil 1 µg/kg), post‐op for 48 h continuous wound irrigation (saline (5 mL/h), every 12 h diclofenac (75 mg in 50 mL/20 min)), PCA (morphine, no basal rate, demand 1 mg, lockout 5 min, max 25 mg/4 h), as needed paracetamol (1 g/6 h) Adjuvants: none Immediate post‐op pain control: pain and analgesic consumption significantly improved
Outcomes	Dichotomous: "chronic postsurgical pain" and scar/wound pain at 6 months Continuous: none reported Secondary: punctuate wound hyperalgesia for the first 48 h. Analgesic consumption at 6 months. Wound healing and complications such as hypotension, nausea or vomiting
Notes	The study author responded to our request for clarification, but with information differing from the published data. Funding sources: "support was provided solely from institutional and/or departmental sources." Conflicts of interest: no conflict of interest statement was given.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "...according to a randomized, prospective, blinded protocol...The parturients were randomly assigned using computer‐generated random numbers..."
Allocation concealment (selection bias)	Unclear risk	Allocation concealment was not explicitly described.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "the patient, the person in charge of perioperative management,... were not aware of the patient group assignment."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "the staff involved in data collection were not aware of the patient group assignment." The study author responded to our inquiry that "the research nurse was blinded to the group allocation‐ there was no code on the questionnaire, she used."
Incomplete outcome data (attrition bias) All outcomes	Low risk	A per‐participant analysis was performed, with no attrition reported. But the study author responded: "patients were excluded from the data analysis (intraoperative failure of intrathecal anaesthesia and intra‐wound catheter out, which did not allow a 48h postoperative follow up). We continued the inclusion of patients following the randomisation and at the end of the random list, we add 1 patient in ropivacaine group and 1 patient in diclofenac group (in the same order than those patients were excluded from the study).” Even though no formal ITT analysis was performed, only 2/90 participants were excluded, reducing the likelihood of bias.
Selective reporting (reporting bias)	Low risk	Study protocol not available but published report includes all the expected outcomes.
Null bias	Low risk	Quote: "for the first 12 h after surgery, patients receiving a subcutaneous infusion of ropivacaine reported lower VAS pain scores at rest and during movement than those receiving local saline infusion... Wound infiltration with ropivacaine was also more effective than saline to relieve visceral pain at 12 h after surgery."