Albi‐Feldzer 2013.

Methods	Triple‐blinded (participant, provider, outcome assessor) clinical RCT Assignments were computer‐generated Follow‐up: 1 year
Participants	Participants: 260 women aged 18‐85 from 4 cancer hospitals in France Operation: breast cancer surgery (both breast‐conserving and mastectomy with or without axillary or sentinel node dissection) 2 groups, size: 117/119 Age (± SD): 56 (± 12), 57 (± 13) Men/women: 0/117, 0/119 Patient co‐morbidities: breast‐conserving surgery with axillary lymph node dissection, group 1, 2 (± SD) 53 (± 45.3), 62 (± 52.1), mastectomy with axillary lymph node dissection or sentinel lymph node dissection, group 1, 2 (± SD): 53 (± 45.3), 48 (± 40.3), mastectomy without axillary lymph node dissection or sentinel lymph node dissection, group 1, 2 (± SD): 11 (± 9.4), 9 (± 7.6)
Interventions	Group 1 (ropivacaine): at end of surgery before suturing, 3 mL‐4 mL infiltration of 0.375% ropivacaine along each site of SC and deep layers of breast and axillary incisions, 2nd and 3rd intercostal space, humeral insertion of major pectoralis (received 3 mg/kg of 0.375% ropivacaine) Group 2 (saline): at end of surgery before suturing, 3 mL‐4 mL infiltration of saline along each site of SC and deep layers of breast and axillary incisions, 2nd and 3rd intercostal space, humeral insertion of major pectoralis (receive 0.8 mL/kg saline Both groups: premedicated with oral hydroxyzine (2 mg/kg) 1 h before surgery. GA induction with propofol, sufentanil, maintenance with nitrous oxide in O2, sevoflurane or desflurane, sufentanil bolus as required. Post‐op pain control with oral paracetamol and ketoprofen and rescue with morphine PCA for 24 h (bolus dose 1 mg on demand, lockout 5 min). Ondanestron 4 mg for nausea/vomiting +/‐ droperidol 1.25 mg every 8 h Adjuvants: none Immdiate post‐op pain control: significantly improved
Outcomes	Dichotomous: pain/no pain at 3 months only Continuous: BPI score at 3, 6, 12 months Other reported: neuropathic pain score, hospital anxiety and depression score at 3, 6, 12 months
Notes	For dichotomous pain, BPI score of ≥ 3 was used as cut off Funding sources: support was from institutional/departmental sources. The study author responded to our request that "Astra Zeneca only paid the insurance for the study and Astra Zeneca had no role in conceiving the study, designing the protocol, executing the trial and or analysing and interpreting the results" Conflicts of interest: there were no other conflicts of interest to report.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "a balanced block stratified randomization scheme was used for patient allocation. Stratification was performed on the basis of hospital and type of surgery (conservative or not). Patients were randomized in randomly permuted blocks of four or six patients in each striatum. Assignments were computer generated"
Allocation concealment (selection bias)	Low risk	Quote: [Assignments were] "maintained in sequentially numbered, opaque, sealed envelopes...the envelope was opened in an isolated room on the day of surgery, and patients were assigned to either the placebo group or the ropivacaine group"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "before induction of anaesthesia, an operating room nurse read the results of randomization to prepare the solution of normal saline or ropivacaine in identical syringes... The solution was prepared in an isolated room and the nurse did not have any further contact with the patient. No other physician or nursing staff member was aware of the contents"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "pain was evaluated by a nurse who was blinded to the treatment group". Patients filled out questionnaires at inclusion and 3 months, 6 months and 1 year after surgery to evaluate chronic pain
Incomplete outcome data (attrition bias) All outcomes	Low risk	24 participants were excluded after randomization because of withdrawal of consent or failure to meet inclusion criteria. The groups to which these belonged was not reported, but there were fairly equal numbers in those that were included and received treatment (117 vs 119). At 3 months, there were 6 participants who were lost to follow‐up or had missing outcome data in the ropivacaine group, and 11 participants lost to follow‐up or with missing BPI data in the placebo group. these are low numbers when compared to the total studied population, and fairly balanced and reasons are listed for each group. No report on the exact number of participants with missing data at 6 or 12 months' follow‐up, only states "The maximum percentage of missing data for each point (0, 3, 6, and 12 months) in both arms was less than 5% (range: 0%‐5%). ITT was performed
Selective reporting (reporting bias)	Low risk	The primary and secondary outcomes listed in the protocol were all reported.
Null bias	Low risk	Quote: "measurement of pain on the VAS showed lower scores at rest and during mobilization in the first 90 min after the end of surgery in the ropivacaine group than in the control group (P < 0.001)... Ropivacaine wound infiltration decreased immediate postoperative pain in the PACU and increased the percentage of pain‐free patients (VAS = 0) for the first 48h"