Methods	Randomisation: dietitian allocated using prepared envelopes Allocation concealment: Unclear Participants masked: No Providers masked: No Outcome assessors masked: Yes Summary risk of bias: medium or high
Participants	N: 1571 int., 1543 Control Level of risk for CVD: High (men being treated for angina) Male: 100% Mean age, sd: 61.1 int., 61.1 control Age range: Unclear Smokers: 25% int., 23% control Hypertension: 49% int., 47% control Location: UK
Interventions	Type: dietary advice (to eat more oily fish) Intervention: Most (1109) advised to eat at least 2 weekly portions of fatty fish OR take MaxEPA capsules, 3/d (0.5g EPA/d). But 462 participants were sub-randomised to receive only fish oil capsules, not dietary fish advice. Control: No such dietary advice or capsules. Compliance: Postal dietary questionnaire suggested dietary EPA intake increased by 2.4g /week int., 0.2g /week control Length of intervention: 36 to 108 mo
Outcomes	Main study outcome: total mortality Dropouts: none for mortality Available outcomes: total and CV deaths, sudden death Response to contact: Yes
Notes	Some of each group were also advised on high fruit, veg and oat diets, and those who received neither fish nor fruit advice received ‘non-specific’ dietary advice. All those whose BMI >30 in both groups received weight reduction advice
Risk of bias
Item	Authors’ judgement	Description
Allocation concealment?	Unclear	B - Unclear