Smythe 1994.

Study characteristics
Methods	Parallel, 24 h
Participants	PCA 19, control 17 Hysterectomy
Interventions	PCA: morphine. Bolus/lockout/4 h limit: 1 mg/6 min/NR or meperidine. Bolus/lockout/4 h limit: 10 mg/6 min/NR Control: IM meperidine 75 mg to 100 mg every 3 to 4 h prn
Outcomes	Pain intensity, satisfaction, cost, adverse effects, nursing and pharmacy time
Source of funding	American Association of Colleges of Pharmacy New Investigator grant
Notes	Withdrawals: PCA ‐ severe nausea: 1 patient discontinued after 2 h QS = 1 (R = 1, DB = 0, W = 0)
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 blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	3 orthopedic surgery patients were excluded as a result of few orthopedic surgeons willing to allow their patients the chance of PCA and conventional options; ITT analysis based on the way Results are presented
Selective reporting (reporting bias)	Low risk	All outcomes described in Methods section are reported in Results section
Other bias	High risk	Very small sample size