Zeng 2004.

Study characteristics
Methods	Study design: randomised, double controlled study Total duration of study: 36 months Details of any 'run‐in' period: washout period of 2 weeks Number of study centres and location: Chengdu No 2 Hosp, Chengdu, China Study setting and date of study: outpatients; no details given
Participants	Number randomised: 286 participants Number lost to follow‐up/withdrawn: no details given Number analysed: 286 participants Number of interest: 286 participants Mean age: no details given Age range: no details given Gender: no details given Severity of condition: hypercholesterolaemia Diagnostic criteria: no details given Smoking history: no details given Inclusion criteria: no details given Exclusion criteria: no details given
Interventions	Intervention: pravastatin 20 to 40 mg/day Comparison: fish oil 9 g/day Concomitant medications: no details given Excluded medications: no details given
Outcomes	Primary outcome: measure of carotid plaque Secondary outcome: no details given Time points reported: "follow‐up 36 months and checked by B‐ultrasonography"
Notes	Funding for trial: no details given Notable conflicts of interest of trial authors: no details given Protocol: no details given
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Two hundred eighty six patients with carotid plaques and hypercholesterolemia were assigned to a randomized double controlled study."
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not reported
Selective reporting (reporting bias)	Unclear risk	Not reported
Other bias	Unclear risk	Not reported