Kitamoto 1971.

Methods	Randomised, double‐blind, placebo controlled treatment trial of oral amantadine. The trial took place during the 1968 to 1969 influenza season throughout Japan
Participants	79 participants were randomised to receive amantadine (200 mg/day for adults) and 76 placebo for 7 days within 48 hours of developing symptoms
Interventions	Amantadine and placebo in a treatment role
Outcomes	Case definition was based on symptoms and serological confirmation of infection. Outcomes were duration of fever (in days), defined as a temperature of more that 37 degrees centigrade and there were no drop‐outs from the study Safety: adverse events were reported as nil
Notes	Although randomisation was clearly applied and no drop‐outs are reported, no description of allocation and concealment is given making its assessment impossible. In addition the follow up of 353 participants is unclear. The authors conclude that treatment started within 2 days of symptom onset shortened significantly the duration of illness and of high fever but did not affect asymptomatic influenza
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear