Kenady 1992.

Study characteristics
Methods	Parallel, 72 h
Participants	PCA 35, control 18 Cholecystectomy
Interventions	PCA: morphine. Bolus/lockout/4 h limit: NR Control: IM morphine ‐ no details
Outcomes	Pain relief and intensity, opioid consumption, level of sedation, interference of pain with postoperative recovery, dimensions of pain experience (tiring, frightening, punishing), ability to move around/breath/rest, LOS
Source of funding	Not reported
Notes	Withdrawals: admitted to ICU (n = 1), PCA malfunction (n = 1) QS = 2 (R = 1, DB = 0, W = 1)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not explicitly stated, but appears to be unblinded
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	2 withdrawals, as detailed in Notes above. Not explicitly stated, but appears that all remaining participants completed study
Selective reporting (reporting bias)	Unclear risk	All outcomes described in Methods section are reported in Results section. P values only reported for some secondary outcomes
Other bias	Unclear risk	Small sample size