Abdel‐Aleem 2012.

Study characteristics
Methods	RCT.
Participants	Inclusion criteria: Women undergoing elective CS at term were eligible N = 173 but 53 (31%) were excluded because of intraoperative nausea and vomiting, leaving 120 for analysis Exclusion criteria: Any contraindication to spinal, contraindication/allergy to IT morphine, GI condition causing vomiting, hyperemesis, obesity, previous PONV, migraine, skin allergy causing itching, psych. Also excluded post‐enrolment if suffered intraoperative nausea and vomiting.
Interventions	Intervention: corticosteroid (Comparison 3) Dexamethasone (8 mg IT). N = 60. Comparator: placebo Normal saline (IT). N = 60.
Outcomes	Nausea, vomiting, number of vomiting attacks, need for anti‐emetics, sedation, itch, respiratory depression, pain, satisfaction (retching classified as vomiting).
Notes	Setting: Assiut University Hospital, Egypt. Dates: February 2008 to December 2009. Funding source: not reported Declaration of interest: none declared. We wrote to authors for clarification on whether the 53 women were excluded pre or post randomisation as it is unclear from the text of the publication. Spinal with bupivacaine and 200 mcg IT morphine
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "computer based random allocation table"
Allocation concealment (selection bias)	Low risk	Quote:“sealed opaque envelopes consecutively numbered and coded”
Blinding of participants and personnel (performance bias) All outcomes	Low risk	the patient ... was unaware of which intervention had been received
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Those assessing the outcomes were also unaware of which intervention had been received.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	53 patients were excluded enrolment although it is unclear if this was before or after randomisation.
Selective reporting (reporting bias)	Unclear risk	We were unable to assess the trial protocol.
Other bias	Low risk	Similar baseline characteristics