How 1988.

Methods	Randomised, controlled trial comparing efficacy of transdermal scopolamine with placebo for preventing seasickness in both experienced and inexperienced sailors
Participants	122 officers and naval men who were either experienced (< 1 year in navy, n = 59) or inexperienced (< 1 year in navy, n = 63). Participant ages ranged from 19 to 45 years.
Interventions	Transdermal Scopaderm TTS (1.5 mg scopolamine) or identical placebo patches applied 4 hours prior to sailing and then replaced every third day during sea voyage
Outcomes	Subjective analogue scale measurement of degree of seasickness experienced during previous 24 hours at 8am every day
Notes	No restrictions of food, water or other medications were imposed Schulz rating: randomisation B; allocation concealment B; selection bias B; blinding A
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear