Mounir 2010

Methods	Double‐blinded (participant/outcome assessor), placebo‐controlled, randomized clinical trial Sequence generation unclear Follow‐up: 6 months
Participants	Participants: men in a military teaching hospital in Rabat, Morocco Operation: inguinal hernia repair groups, size: 20/22 Age: years (range ): 46 ± 5; 40 ± 4 Men/women (group 1, 2): 20/0; 22/0 Comorbidities (group 1, 2, 3): none reported Remarks: only ASA I and II
Interventions	Group 1 (bupivacaine wound infiltration): spinal (12.5 mg hyperbaric bupivacaine + 25 µg fentanyl, intrathecally), postincision SC infiltration of the skin with bupivacaine (0.5%, 20 mL), post‐op 1 g paracetamol, ketoprofen (100 mg), morphine 3 mg as needed for breakthrough pain Group 2 (saline/placebo wound infiltration): spinal (12.5 mg hyperbaric bupivacaine + 25 µg fentanyl, intrathecally), postincision SC infiltration of the skin with saline (0.9%, 20 mL), post‐op 1 g paracetamol, ketoprofen (100 mg), morphine 3 mg as needed for breakthrough pain Adjuvants: none Immediate post‐op pain control: significantly improved
Outcomes	Dichotomous: pain/no pain at 3 and 6 months, (pain differentiated in mild, moderate and severe) Continuous: none Secondary:
Notes	The report leaves it unclear if postoperative analgesics were given intravenously or orally. We contacted the study author for clarification of randomisation, allocation and blinding methods, but did not get a response. Funding sources: no funding sources specified Conflicts of interest: no conflict of interest declared
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: “etude prospective randomisee”, (prospective randomized trial) “La randomisation etait realise au cours de la visite preanesethesique par envelopes cachetees et numerotees...” (the randomization was realized during the preoperative visit with numbered and sealed envelopes) Even so the study is reportedly "randomized", the randomization method is not explained, hence bias is possible.
Allocation concealment (selection bias)	Unclear risk	Quote: “la randomisation etait realise au cours de la visite preanesethesique par envelopes cachetees et numerotees...” It is unclear if and how and how long the allocation was concealed to the person enrolling the participants or to the anaesthesia provider. Bias is therefore possible.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: “l’anesthesiste remettait au chirurgien une seringue”, “le chirurgien, qui ignorait la solution de infiltration”, (The anesthesiologist passed a syringe to the surgeon, ... the surgeon did not know the solutions to be infiltrated.) Possibly no blinding of the anaesthesia providers, but participant and surgeon were blinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote:” a six mois" "evaluee grace a un questionnaire rempli par tous les patients lors de leur consultation de chirurgie de controle?”. (at six months ... evaluated by a questionnaire filled out by all participants during their surgical follow‐up visit) The outcome observer (surgeon) was blinded and the outcome was reported with the use of a questionnaire.
Incomplete outcome data (attrition bias) All outcomes	Low risk	The uneven numbers of 22 and 20 in both groups leaves open the possibility of an error in the allocation process, cross over, attrition or incorrect randomisation and this is not addressed in the report. Bias seems still unlikely, due to the low attrition.
Selective reporting (reporting bias)	Low risk	Primary outcomes fully reported on
Null bias	Low risk	Quote: "there was a significant reduction of postoperative pain in the bupivacaine group at rest as well as with coughing"