Schmitz 2002.

Methods	Study design: randomised, double‐blind clinical trial
Participants	Country: United States No. of participants: 24 Age: 46 to 58 years Gender: M = 11, F = 13 Inclusion criteria: newly placed PTFE graft Exclusion criteria: patients needing fistula revision; history of gastro‐intestinal bleeding; already taking warfarin or an anti‐platelet agent; terminal or life‐threatening disease; pregnancy; or malignant hypertension
Interventions	Treatment: 4000 mg fish oil once daily Control: placebo od Duration: 12 months (medication started within 2 weeks of graft placement)
Outcomes	Primary: graft thrombosis
Notes	PTFE grafts
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Permuted block randomisation scale
Allocation concealment (selection bias)	Low risk	No pre‐allocation bias
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Placebo and treatment capsules manufactured by the same company
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to assess
Incomplete outcome data (attrition bias) All outcomes	Low risk	All randomised participants received the appropriate treatment. Only one was lost to follow‐up
Selective reporting (reporting bias)	Unclear risk	Pre‐study protocol not available
Other bias	Low risk	Nil obvious