Franzen 1993

Methods	RCT, parallel (n‐3 EPA + DHA vs MUFA), 12 months Summary risk of bias: moderate to high
Participants	Adults with documented coronary heart disease N: 15 intervention, 15 control Level of risk for CVD: high Men: unclear Mean age in years (SD): 52 (9) intervention, 54 (7) control Age range: not reported Smokers: 87% intervention, 100% control Hypertension: not reported Medications taken by at least 50% of those in the control group: aspirin, beta‐blockers Medications taken by 20%‐49% of those in the control group: not reported Medications taken by some, but less than 20% of the control group: not reported Lipid lowering medications were not allowed Location: Germany Ethnicity: not reported
Interventions	Type: fish oil capsules Comparison: EPA + DHA vs MUFA Intervention: 9 × 1 g capsules/day of fish oils (20% EPA, 15% DHA, 3.15 g/day total omega 3). Dose: 3.15 g/d EPA + DHA Control: 9 × 1 g capsules/day olive oil (which contains 6.3 g/day MUFA, 1.35 g/day SFA, 1.35 g/d total omega 6 fat) Compliance: assessed by pill counts and FA in body tissue analysis Length of intervention: 12 months
Outcomes	Main study outcome: blood lipids and FA in body tissues Dropouts: 0 intervention, 0 control Available outcomes: mortality (nil death), CVD events (nil), lipids (only TC used as the others were different at baseline), adverse events, serum fatty acids Response to contact: yes
Notes	Study funding: unclear
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated list
Allocation concealment (selection bias)	Unclear risk	No details. They received their initial allocation in a sealed box in person; subsequent doses arrived in the post
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No further details beyond stating "double blind"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No details
Incomplete outcome data (attrition bias) All outcomes	Low risk	No attrition
Selective reporting (reporting bias)	Unclear risk	No trial register or protocol found
Attention	Low risk	No difference between groups
Compliance	Unclear risk	Measured but no results
Other bias	Low risk	None noted