Gundes 2000.

Methods	Triple‐blind (participant, provider, outcome assessor) clinical RCT Sequence generation was randomized but not described Follow‐up: 3 months
Participants	Participants: 45 participants (no age requirement) at a university hospital in Kocaeli, Turkey Operation: iliac crest bone harvesting (surgical procedures included vertebral fusion, fracture grafting and grafting for tumour resection) 3 groups, size: 15/15/15 Age (range), group 1, 2, 3: 46 (16‐70), 48 (18‐71), 51 (19‐73) Men/women, group 1, 2, 3: 5/10, 6/9, 6/9 Comorbidities: vertebral fusion (n), group 1, 2, 3: 6, 5, 6. Fracture grafting (n), group 1, 2, 3: 6, 7, 7. Tumour grafting (n), group 1, 2, 3: 3, 3, 2.
Interventions	Group 1 (control): 20 mL of 0.9% sodium chloride solution via iliac crest catheter within 10 min after surgery Group 2 (bupivacaine only): 20 mL of 0.9% NaCl with 50 mg bupivacaine via iliac crest catheter within 10 min after surgery Group 3 (morphine‐bupivacaine group): 20 mL of 0.9% NaCl solution with 5 mg morphine and 50 mg bupivacaine via iliac crest catheter within 10 min after surgery. All groups: standardized general anaesthesia with thiopental, vecuronium, N2 in O2 and isoflurane. Regional infusions via fine bore epidural catheter at iliac crest donor site, tip between muscle and bone at lateral surface of ilium, started 10 min after surgery. Post‐op pain control: participants requested reinjection of LA at iliac crest when donor site became painful (5 mL 0.9% NaCl with 12.5 mg bupivacaine), morphine PCA 1 mg bolus, 5 min lockout, 4‐h limit 20 mg Adjuvants: none Immediate post‐op pain control: significantly improved, significantly reduced analgesic consumption
Outcomes	Dichotomous: pain and dysaesthesia vs none at 3 months post‐op Continuous: none Other reported: none
Notes	Postoperatively, all participants in all groups received reinjection of LA (5 mL NaCl and 12.5 mg bupivacaine) into iliac crest when donor site became painful. Thus, control group did receive some bupivacaine in post‐op period. Average number of injections received reported by group. We acknowledge the response provided by the study author regarding blinding, randomization, allocation concealment and source of funding and conflict of interest statement. Funding sources: the study author reports the study was "not funded by any kind of resource." Conflicts of interest: "the authors have no conflict of interests of any kind (financial, commercial or otherwise)."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Study author responded that he "did a simple randomization; as every second patient was included in group two; every third patient was included in group three, then reversing it as every fourth patient in group three, every fifth patient in group two, every sixth patient in group one; and so on". He did not mention this to his collaborators and he did not perform or attend any surgeries in the study. He did not mention his randomization technique to the other collaborators
Allocation concealment (selection bias)	Low risk	Study author responded, quote: "all the medications had been prepared by senior anesthesiology resident, according to me or my chief residents' instructions. All were prepared in 50 cc identical syringes without any label"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Study author responded they, quote: "blinded both the patients and anaesthesiologists"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Study author states "Dr L.K (anaesthesiologist) did the postoperative (24 hour) evaluation of the patient including VAS score without knowing the group of the patient. He also evaluated patients 12 weeks after the surgery, also without knowing the group of the patient.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data
Selective reporting (reporting bias)	Low risk	Published report includes all expected outcomes
Null bias	Low risk	Quote: "the VAS score, analgesic consumption and request for reinjection of local anaesthetic into the donor site in the early postoperative period (24th hour) were significantly higher in the control group than in the other two study groups"