Methods |
Individual-level randomised controlled trial |
Participants |
2053 participants (205 aspirin; 205 thiazide; 209 thiazide + ramipril; 207 thiazide + atenolol; 205 ramipril + atenolol; 204 thiaizde + ramipril + atenolol; 204 thiaizide + ramipril + atenolol + aspirin; 202 simvastatin; 412 Polycap [thiazide + ramipril + atenolol + simvastatin + aspirin); 45 to 80 years old without prior cardiovascular disease but with at least one risk factor: type 2 diabetes; blood pressure >140/90 mmHg but <160/100 mmHg; smoker within the past five years; waist-to-hip ratio >0.85 for women and 0.90 for men; LDL cholesterol >3.1 mmol/L but less 4.5 mmol/L or HDL cholesterol <1.04 mmol/L |
Interventions |
Intervention: Polycap (thiazide 12.5 mg, atenolol 50 mg, ramipril 5 mg, simvastatin 20 mg, aspirin 100 mg) Control: 8 other drug/drug combination groups listed above |
Outcomes |
LDL for the effect of lipid-lowering drugs, BP for antihypertensive drugs, heart rate for the effects of atenolol, urinary 11-dehydrothromboxane B2 for the antiplatelet effects of aspirin, rates of discontinuation of drugs for safety |
Notes |
Control: active |
Risk of bias |
Bias |
Authors' judgement |
Support for judgement |
Random sequence generation (selection bias) |
Low risk |
Central computer randomisation |
Allocation concealment (selection bias) |
Low risk |
Central computer randomisation |
Blinding of participants and personnel (performance bias) All outcomes |
Low risk |
Placebo control using identical capsule |
Blinding of outcome assessment (detection bias) All outcomes |
Low risk |
Double-blinding reported; probably occurred given research team's prior studies |
Incomplete outcome data (attrition bias) All outcomes |
Unclear risk |
Unclear how missing SBP and LDL-C data at week 12 follow-up were handled |
Selective reporting (reporting bias) |
Low risk |
Primary outcomes reported |