Parker 2001.

Methods	RCT Cross‐over
Participants	Participants with ALL receiving intrathecal chemotherapy +/‐ maintenance chemotherapy. Median age 6 years (range 2 to 17 years). 12/26 were male
Interventions	High‐dose ondansetron 0.45 mg/kg IV 15‐minute infusion 30 minutes prior to lumbar puncture Low‐dose ondansetron 0.15 mg/kg IV 15‐minute infusion 30 minutes prior to lumbar puncture Placebo (saline) IV 15‐minute infusion 30 minutes prior to lumbar puncture
Outcomes	Parental report of number of vomiting episodes recorded
Notes	Given the low potential of chemotherapy itself, seems more like a trial of post‐anaesthetic antiemetics than of chemotherapy‐induced emesis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not stated
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding (performance bias and detection bias) Acute nausea	High risk	Not reported
Blinding (performance bias and detection bias) Acute vomiting	Low risk	States double‐blind. No further details. Blinding of care provider: yes Blinding of participant: yes Blinding of outcome assessors: yes
Blinding (performance bias and detection bias) Other outcomes	High risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	Dropouts between cross‐overs (1 before placebo, 2 before ondansetron 0.45 mg/kg)
Selective reporting (reporting bias)	Low risk	—
Other bias	Low risk	No other risk of bias noted