Gill 2012

Methods	RCT, parallel, (EPA + DHA vs unclear), 24 months Summary risk of bias: moderate or high
Participants	Adults with Metabolic syndrome N: unclear, total randomised 101 Level of risk for CVD: low Men: 47% total, no details by group Mean age in years (SD): 55 (10) total Age range: 18‐75 years Smokers: 0% intervention, 0% control Hypertension: not reported Medications taken by at least 50% of those in the control group: not reported 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 Location: USA Ethnicity: unclear
Interventions	Type: supplement (fish oil capsules) Comparison: EPA + DHA vs placebo (unclear what) Intervention: fO3FA capsules 1.8 g of EPA + DHA daily. Dose: 1.8 g/d EPA + DHA Control: matching placebo supplement Compliance: not reported Length of intervention: 12 months
Outcomes	Main study outcome: change in carotid IMT Dropouts: unclear Available outcomes: lipids, insulin and glucose are stated as secondary outcomes but no usable data published Response to contact: no
Notes	Results cannot be used as numbers are not reported by study arm. Study funding: unclear, but mentions that Pfizer, NIH and "Northwest Lipids Clinic" are partners
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details
Allocation concealment (selection bias)	Unclear risk	No details
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No data
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No data
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No data
Selective reporting (reporting bias)	High risk	Inadequate detail in reporting as no full text publication found; Gill 2014 does give detail on carotid IMT, but not on other primary or secondary outcomes. The trial was prospectively registered (registered July 2006, unclear when recruitment started, final data collection 2011, first data published 2012).
Attention	Unclear risk	No data
Compliance	Unclear risk	No data
Other bias	Unclear risk	No data