Ögün 2001.

Study characteristics
Methods	Randomised, double‐blind, placebo control
Participants	N = 47, 100% women
Interventions	Ketamine 1 mg/kg bolus IV pre‐incisionally and after excision of tissue specimen
Outcomes	Pain intensity (VAS, VRS) reported at 0, 1, 2, 4, 6, 12 and 24 h postoperatively. Analgesic consumption reported at 24 h postoperatively. AEs
Surgery type	Mastectomy
Group numbers after end of study (treatment/control)	16/15
Age of patient population (treatment/control)	47.2 ± 12.7 47.8 ± 14.2
Notes	Article in Turkish. No mention of sponsorship or funding
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation process not described
Allocation concealment (selection bias)	Unclear risk	Allocation concealment process not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Only mentioned double‐blind but lacks description of how it was achieved
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Only mentioned double‐blind but lacks description of how it was achieved
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals
Selective reporting (reporting bias)	Low risk	Predefined outcomes reported
Size	High risk	15 and 16 participants per treatment arm