Study designs of evaluations included in the review
All types of studies were eligible for inclusion. Parallel group, double-blind randomised controlled trials (RCTs) were eligible for inclusion in the meta-analysis if patients were treated identically except for the intervention under investigation, and complete data were available for end points in the control and treatment groups.
Specific interventions included in the review
Studies examining the use of intravenous, peri-operative administration of dexamethasone were eligible for inclusion in the meta-analysis, as were those examining the use of any method of peri-operative steroid administration. Non-steroid treatments such as ondansetron and midazolam were excluded.
Included studies administered a single intravenous dose of dexamethasone in either doses ranging from 150 microg/kg to 1 mg/kg (maximum 8 to 25 mg) or in a dose of 8 mg/m2 of body surface area. All included studies were placebo-controlled.
Participants included in the review
Tonsillectomy patients were eligible. Studies concentrating on anaesthetic technique, upper airways obstruction, obstructive sleep apnoea and other paediatric diseases were excluded. The participants appear to have all been children, although this was not stated explicitly. Techniques for tonsillectomy included cold knife dissection or electrocautery dissection.
Outcomes assessed in the review
Studies that assessed any post-operative outcomes were eligible. The outcomes actually assessed were post-operative emesis (assessed 'after surgery', 'in hospital', day of discharge, day after discharge or at between 3 and 24 hours), oral intake (assessed as soft or regular, or solid diet on first and third post-operative day), post-operative pain, and hours till first post-operative oral intake. Outcomes were assessed at 24 hours, and 3 to 7 days post-operatively.
How were decisions on the relevance of primary studies made?
Each of the identified articles was independently reviewed by two of the authors, and any discrepancies were resolved through mutual discussion and review of the article; foreign language article was reviewed with a translator.