Methods	Randomisation: over the telephone by computer network, stratified by hospital, assigned from program based on biased coin algorithm, by investigators or pharmacists Allocation concealment: Done Participants masked: No Providers masked: Unclear Outcome assessors masked: Yes Summary risk of bias: medium or high
Participants	N: 5665 int., 5658 control Level of risk for CVD: High (people with recent myocardial infarction) Male: 85.7% int., 84.9 % control Mean age, sd: 59.3 int., 59.5 control Age range: <50 to >80 Smokers: 42.6% int., 42.3% control Hypertension: 36.2% int., 34.9% control Location: Italy
Interventions	Type: supplement (capsule) Intervention: Omacor gelatine capsules, 1/d (0.9g/d EPA + DHA daily) Control: nil Compliance: capsule counts, 11.6% had stopped taking Omacor by 12 mo, 28.5% by the end of the study Length of intervention: median follow up 40 mo
Outcomes	Main study outcome: death, stroke, MI Dropouts: Unclear Available outcomes: total , sudden and CV deaths, MI, stroke, angioplasty or CABG, combined CV events, lipids, side effects Response to contact: No
Notes	Half of both groups were on vitamin E supplements (300 mg/d synthetic a-tocopherol)
Risk of bias
Item	Authors’ judgement	Description
Allocation concealment?	Yes	A - Adequate