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. Author manuscript; available in PMC: 2015 Apr 16.
Published in final edited form as: Cochrane Database Syst Rev. 2014 Apr 16;4:CD009868. doi: 10.1002/14651858.CD009868.pub2

Wald 2012.

Methods Individual-level randomised double-blind placebo-controlled cross-over trial
Participants 86 individuals (43 Polypill then placebo; 43 placebo then Polyp ill) aged 50 years or over without history of cardiovascular disease who were previously taking simvastatin and blood pressure lowering drugs; limited to participants living in London or could travel easily to London
Interventions Intervention: fixed-dose combination (amlodipine 2.5mg, losartan 25mg, hydrochlorothiazide 12.5mg, simvastatin 40mg) daily for 12 weeks
Control: placebo
Outcomes SBP, DBP, total cholesterol, LDL-C, HDL-C, triglycerides, apoB, adherence
Notes Control: inactive/placebo
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Computer generated block randomisation
Allocation concealment (selection bias) Low risk Computer generated block randomisation with sequential identical blister packs
Blinding of participants and personnel (performance bias) All outcomes Low risk Placebo controlled
Blinding of outcome assessment (detection bias) All outcomes Low risk Outcome assessors reported as being blinded
Incomplete outcome data (attrition bias) All outcomes Low risk Primary outcomes reported
Selective reporting (reporting bias) Unclear risk Adverse event data not clearly described; only proportion of individuals with “symptom”, which was assumed to be an adverse event
Other bias Low risk No need for intention-to-treat analysis as cross-over design. Any losses to follow-up clear