| Methods |
Design: three group parallel trial
Purpose: examine the prophylactic effect of placebo and various drugs on seasickness |
| Participants |
Patients: soldiers undergoing amphibious training
Baseline comparability: NS |
| Interventions |
Placebo: lactose capsules
Untreated: no capsules
Experimental: various belladonna alkaloid and barbiturate preparations
(Co‐intervention: NS) |
| Outcomes |
Number of patients with seasickness |
| Notes |
The randomisation procedure was in principle open to selection bias, however, the allocation took place openly under full military discipline so we do not think selection bias was likely. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Low risk |
'cards from deck so stacked as to ensure a random distribution' |
| Allocation concealment? |
Unclear risk |
See notes |
| Blinding?
Outcome assessor |
Unclear risk |
Not relevant as patient reported outcome |
| Incomplete outcome data addressed?
All outcomes |
High risk |
|
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
Low risk |
|
| No signs of variance inequality or skewness? |
Unclear risk |
Not relevant (binary outcome) |
| Trial size > 49? |
Low risk |
N = 563 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
|
