Morad 2009.

Study characteristics
Methods	Parallel, outcomes assessed until participants discharged from neuroscience critical care unit (10 h or longer)
Participants	PCA 39, control 40 Elective supratentorial craniotomy, mostly due to tumor
Interventions	PCA: fentanyl. Bolus/lockout/1 h limit: 0.5 µg/kg/15 min/4 demand dose per h Control: IV fentanyl 25 to 50 µg every 30 min prn
Outcomes	Pain intensity, incidence of uncontrolled pain (defined as a pain score ≥ 5/10 for > 2 hours), incidence of respiratory depression requiring an opioid antagonist or institution of ventilatory support, neurological changes including the number of emergency postoperative imaging studies obtained for evaluation of neurological changes, incidence of pruritus, incidence, duration, and intensity of nausea and vomiting, vital signs
Source of funding	Supported in part by grants from the Jacob and Hilda Blaustein Foundation, National Institutes of Health Grant No. NS041865
Notes	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	Unblinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	Most dropouts occurred before PCA or PRN were started, i.e., during the operative phase, and were mostly due to protocol violations or unanticipated neurological outcomes. In remaining participants, no withdrawals occurred before 10 h of data collection and were balanced between groups (3 PCA vs 3 PRN)
Selective reporting (reporting bias)	Low risk	Protocol not available. All outcomes described in Methods section are reported in Results section
Other bias	Unclear risk	Small sample size