Randomised double-blind placebo controlled trial of effect of Ginkgo biloba on cognitive function in mild-moderate dementia

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Not provided at time of registration

Dr James Warner
Scientific

Senior Lecturer
Imperial College School of Medicine
St Charles Hospital
Exmoor Street
London
W10 6DZ
United Kingdom

Phone	+44 (0)20 8962 4101
Email	j.warner@ic.ac.uk

Primary study design	Interventional
Study design	Randomised double-blind placebo controlled parallel group study
Secondary study design	Randomised controlled trial
Scientific title
Study acronym	DIGGER
Study objectives	Null Hypothesis: high purity ginkgo biloba extract does not improve cognition quality of life or carer burden in individuals with mild-moderate dementia. NB: this study will also assess the magnitude of the Hawthorne effect in dementia trials.
Ethics approval(s)	Received from Multi-centre Research Ethics Committee (ref: MREC/02/6/35).
Health condition(s) or problem(s) studied	Dementia
Intervention	1. The active intervention will be concentrated, standardised Ginkgo biloba extract (25% active Ginkgo-flavoneglycosides), prepared according to accepted guidelines in a 60 mg tablet (EGB-761, Schwabe) 2. The placebo will be 60 mg of inert lactose with 2 mg quinine sulphate
Intervention type	Drug
Phase	Not Specified
Drug / device / biological / vaccine name(s)	Ginkgo extract
Primary outcome measure(s)	Alzheimer's Disease Assessment Scale Cognitive Subscale (ADAS-cog) at six months.
Key secondary outcome measure(s)	All at six months: 1. Participant: Quality of Life scale in Alzheimers disease (QoL-AD), Neuropsychiatric Inventory questionnaire (NPI), Geriatric Evaluation by Relative's Rating Instrument (GERRI), adverse events 2. Carer: European Quality of life questionnaire (EQ-5D), Zarit caregiver Burden Interview (ZBI)
Completion date	31/12/2005

Participant type(s)	Patient
Age group	Senior
Sex	All
Target sample size at registration	200
Key inclusion criteria	1. Aged 55 years and over 2. Clinician's diagnosis of dementia 3. Presence of a carer 4. Consent of patient and carer 5. Sufficient command of English to complete questionnaires 6. Mini Mental State Examination (MMSE-23) score of 15 - 24
Key exclusion criteria	1. Commencement of acetylcholinesterase therapy within two months of recruitment 2. Current anticoagulant therapy 3. Abnormal clotting profile
Date of first enrolment	01/04/2003
Date of final enrolment	31/12/2005

Senior Lecturer

London
W10 6DZ
United Kingdom

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	Results	03/07/2007		Yes	No