Riedemann 1992

Methods	Randomised controlled trial.
Participants	Children aged 6 to 15 years in good health; normal ALT/AST. 260 participants were recruited.
Interventions	1. Inactivated HAV vaccine (Havrix, GSK) (0,1,6 months). 128 participants received the vaccine. 2. Recombinant HBV vaccine (Engerix‐B GSK (identical). 132 participants received the vaccine.
Outcomes	1. Clinical hepatitis A (IgM to HAV). 2. Averse events (fever, headache, malaise, anorexia, nausea, vomiting, any symptoms). 3. Immunogenicity (anti‐HAV IgG).
Notes	Location: Chile Endemicity: high. Follow‐up: 12 months, multiple treatment. Trial conducted under increased hygiene measure as result of earlier cholera outbreak. Drop out: 4 participants.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The trial is described as randomised, but the method of sequence generation is not specified.
Allocation concealment (selection bias)	High risk	A colour code was used to label hepatitis A and control vaccines. From the description provided those involved in the trial could have determined the allocation sequence.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Described as double blind. However, the method of blinding not fully described.
Incomplete outcome data (attrition bias) All outcomes	Low risk	The numbers and reasons for dropouts and withdrawals in all intervention groups were described.
Selective reporting (reporting bias)	Low risk	Expected outcomes reported on.
Other bias	Low risk	Trial appears to be free of other sources of bias.