Tam 2012

Methods	Study design: randomized controlled trial Study dates: August 2009 to January 2011 Diagnostics: virological diagnosis (rapid test for dengue non‐structural protein NS1 silver strip)
Participants	Number of participants: randomized: 225 enrolled (150 in corticosteroid group including 75 in high‐dose group and 75 in low‐dose group; 75 in placebo group) Inclusion criteria: children and young adults Age: 5 to 20 years (enrolled participants were 10 to 15 years of age) with clinically suspected dengue, supported by a positive antigen test for dengue, fever for ≤72 hours and negative pregnancy test Exclusions: those weighing < 20 kg, those with evidence for any dengue‐related complications, symptoms suggesting another infectious disease, or a past history of serious illness or chronic disease including psychiatric/behavioural problems, and those taking regular medications
Interventions	1. prednisolone: low‐dose (0.5 mg/kg) orally once daily for three days 2. prednisolone: high‐dose (2 mg/kg) orally once daily for three days 3. placebo: placebo group was additionally 1:1 randomized to low‐ or high‐dose placebo
Outcomes	1. Number of complications: dengue shock syndrome; ICU admission; severe thrombocytopaenia; significant bleeding; severe abdominal pain; increased liver enzymes 2. Number of adverse events: hyperglycaemia, hypertension, pneumonia, upper respiratory infection Platelet nadir days 3 to 8, 109/L Laboratory endpoints: maximum haematocrit at days 3 to 8; %haemoconcentration Virological endpoints (not of interest for this review) Area under the curve (AUC) log viraemia at days 3 to 6, log 10 copies/mL; time to undetectable viraemia, number and % with undetectable viraemia; days from enrolment, median (interquartile range, IQR) to undetectable viraemia; time to negative NS1: number with negative NS1 %; days from enrolment, median (IQR) to negative NS1
Notes	Location: Hospital for Tropical Diseases, Ho Chi Min City, Vietnam Transmission: not specified Funding: Wellcome Trust Tam 2012 defined platelet nadir < 10,000/μl L = SAE as severe thrombocytopaenia.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "block randomisation"
Allocation concealment (selection bias)	Low risk	Quote: "All participants and study staff were blind to the treatment allocation" and "did not blind the dose allocation, but the placebo group was additionally 1:1 randomized to low‐ or high‐dose placebo to maintain blinding of the drug"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "identical prednisolone and placebo were available", and "placebo group was additionally 1:1 randomized to low‐ or high‐dose placebo to maintain blinding of the drug". They were blind to intervention or placebo, but not to high or low dose.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Email correspondence with author: "The study staff were the outcome assessors and they were blind"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Low losses to follow‐up were reported
Selective reporting (reporting bias)	Low risk	No evidence of selective reporting
Other bias	Low risk	No other bias identified