OMEGA 2009.

Methods	Effect of Omega 3 fatty acids on reduction of sudden cardiac death after MI (OMEGA) 2 arm, parallel RCT (omega 3 vs olive oil), 12 months Summary risk of bias: low
Participants	People who have had an acute myocardial infarction N: 1940 intervention,1911 control (analysed for primary endpoints 1919 intervention, 1885 control) Level of risk for CVD: high Men: 75.1% intervention, 73.7% control Age (median): 64.0 years, intervention, 64.0 years control Age range: unclear (upper and lower quartiles 54‐72) Smokers: 35.9% intervention, 37.5% control Hypertension: 66.9% intervention, 66.1% control Medications taken by at least 50% of those in the control group: statins, ACE inhibitors, beta‐blockers, clopidogrel, aspirin Medications taken by 20%‐49%: diuretics Medications taken by some, but < 20%: AT1 receptor blockers, vit K antagonist, calcium channel blockers, digitalis, amiodarone, oral antidiabetics, insulin Location: Germany Ethnicity: not reported
Interventions	Type: supplement (capsules) Comparison: EPA + DHA vs MUFA Intervention: 1 × 1 g/d Pronova BiCare soft gelatin capsule 'zodin' omega‐3 acid ethyl esters (460 mg/d EPA and 386 mg/d DHA). Dose: 0.85 g/d EPA + DHA Control: 1 × 1 g/d olive oil capsule identical to intervention Compliance: 93.1% of intervention group and 93.2% of control participants took > 70% of capsules Duration of intervention: 12 months
Outcomes	Main study outcome: sudden cardiac death, cardiac arrest Dropouts: Control: 26 (8‐lost to follow‐up, 2‐withdrew before allocation, 16‐excluded.) intervention: 21 Available outcomes: deaths, CV mortality, MACCE, MI, arrhythmias, heart failure, stroke, revascularisation, lipids, authors supplied information on angina, depression, cancers, AF Response to contact: yes
Notes	Study funding: Tromsdorff Arzneimittel commissioned the research
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation code generated by alpha med PHARBIL, done in blocks of 8. Randomisation was stratified by centre.
Allocation concealment (selection bias)	Low risk	Appearance of the drugs or the drug containers did not allow patients and physicians to deduce the study arm. 4‐digit number on a concealed container
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Capsules for placebo and intervention looked the same, randomisation code unknown to investigator (taste and smell not mentioned)
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Classification of adverse events blinded to allocation, and there was a blinded endpoint committee for all pre‐specified outcomes
Incomplete outcome data (attrition bias) All outcomes	Low risk	All events were documented by the investigators and reported to the assigned clinical research organisation and the sponsor. The data safety monitoring board judged any imbalances between the study arms.
Selective reporting (reporting bias)	Low risk	NCT00251134 registered in 2005. Study start date: 2003, Completed: 2008, study design: 2006, Published paper: 2010. All trials registry primary and secondary outcomes reported
Attention	Low risk	Capsules for both arms
Compliance	Low risk	93.1% of intervention group and 93.2% of control participants took > 70% of capsules. EAIC 0.65 intervention, and control
Other bias	Low risk	None noted