Rehmani 2013.

Methods	Allocation: randomized Controlled: active comparator Blinding: double‐blind Arm: 2‐arm, parallel‐group design Centre: single centre Study duration: not reported
Participants	Inclusion criteria: participants presenting to emergency department with acute painful crisis of SCD Exclusion criteria: not reported Baseline characteristics N: 106 participants; 106 VOC episodes Gender: not reported in abstract Age: not reported Number randomized: 54 intervention; 52 control Number completed: not reported Setting and location: King Abdulaziz Hospital, Al Ahsa, Saudi Arabia
Interventions	Treatment group (54 participants; 54 VOC episodes): single IV morphine 0.1 mg/kg Control group (52 participants; 52 VOC episodes): single IV paracetamol 1 g Duration of treatment: duration of painful crisis Follow‐up period: not reported Cointerventions/additional analgesia: rescue analgesics
Outcomes	Primary outcomes Pain intensity (VAS 100 mm) Pain intensity (VRS 1–4) Change in pain intensity after 30 minutes Secondary outcomes Rescue analgesia (morphine) Adverse effects
Notes	Sources of funding: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "106 patients were randomised to treatment, morphine or paracetamol." Comment: no clear method of randomization.
Allocation concealment (selection bias)	Unclear risk	Comment: insufficient information.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: insufficient information.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: insufficient information.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: insufficient information.
Selective reporting (reporting bias)	High risk	Comment: not all outcomes listed in methods were reported in the results, e.g. VRS; however, unclear due to abstract only.
Size	Unclear risk	Comment: total participants 106, 50–199 participants per treatment arm.
Other bias	Low risk	Comment: no other possible sources of bias.