Study	Reason for exclusion
ALLHAT 2003	No data on cognition. Not placebo controlled.
ASCOT 2005	No data on cognition. Not placebo controlled.
Black 2001	No data on cognition
Framingham 1993	Prospective study. Not double blind, randomised, placebo controlled
Hofman 1997	Prospective population based follow‐up study
HOT 1998	Aspirin versus placebo in patients treated with felodipine as baseline therapy
Hsieh 2003	No data on cognition
Kilander 1998	Prospective population‐based study
Lasser 1989	Age of participants 25‐55 years, mean age 51.3 years, not at risk of dementia.
Launer 1995	Prospective population based study
LOMIR‐MCT‐IL	No data on cognition
MRC 1996	Single blind study
Murray 2002	Longitudinal analysis
PROGRESS 2003	Patients had prior stroke or transient ischaemic attack
Richards 2000	Community based survey
Skoog 1996	Longitudinal population study
Starr 1996	Not placebo controlled. Patients received either captopril or bendrofluazide
STOP 1991	No end points as specified for this review
Syst China 1998	Not double blind or adequately randomised
VALUE 2004	No data on cognition