Sahoo 2012.

Study characteristics
Methods	RCT
Participants	56 women Inclusion criteria: ASA I, age 20‐40, elective LSCS Exclusion criteria: contraindications to SAB, patient refusal, unstable haemodynamics, coagulopathy, history of hypersensitivity to ondansetron or local anaesthetic agents, hypertensive disorders of pregnancy, cardiovascular insufficiency, receiving selective serotonin reuptake inhibitors or migraine medications Setting: India
Interventions	Pretreatment with ondansetron versus placebo Group 1: IV ondansetron 4 mg diluted in 10 mL of normal saline given over 1 min, 5 min before spinal anaesthesia Group 2: 10 mL of normal saline IV given over 1 min, 5 min before spinal anaesthesia
Outcomes	Maternal: hypotension, decrease in BP, decrease in heart rate, nausea and vomiting Neonatal: none
Notes	Hypotension: SBP < 90 mmHg or DBP < 60 mmHg Bradycardia: heart rate < 50 bpm
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation chart
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinded anaesthetist assessing outcomes
Incomplete outcome data (attrition bias) All outcomes	Low risk	Not apparent
Selective reporting (reporting bias)	Low risk	Not apparent
Other bias	Low risk	Not apparent