Muehlbach 1995

Methods	Design: Randomised parallel group trial Setting: USA
Participants	N=30, male and female, healthy, adult volunteers aged 19‐30 years Laboratory‐based simulated night shift schedule for 5 consecutive nights
Interventions	Caffeine (n=15), 2mg/kg Placebo (n=15) All participants received 300ml of decaffeinated coffee between 22.20 and 22.50 and again between 01.20 and 01.50 hours on each of the 5 nights. For participants in the caffeine group, caffeine was added to the coffee for the first 3 nights.
Outcomes	SALT performance measure (measured every 2 hours throughout the shift)
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	Correspondence with author ‐ table of random numbers.
Allocation concealment?	High risk	Correspondence with author ‐ allocation was not concealed.
Blinding? All outcomes	Low risk	Participants and laboratory‐based personnel were blind to allocation status.
Incomplete outcome data addressed? All outcomes	Unclear risk	Insufficient reporting of attrition/exclusions to permit judgement of 'Yes' or 'No'.
Free of selective reporting?	Unclear risk	All outcomes described in Methods section are reported in the Results.
Free of other bias?	Low risk	The study appears to be free of other sources of bias.