Contact information
Type
Scientific
Primary contact
Dr James Warner
ORCID ID
Contact details
Senior Lecturer
Imperial College School of Medicine
St Charles Hospital
Exmoor Street
London
W10 6DZ
United Kingdom
+44 (0)20 8962 4101
j.warner@ic.ac.uk
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
QRD/2001/01/07
Study information
Scientific title
Acronym
DIGGER
Study hypothesis
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
Received from Multi-centre Research Ethics Committee (ref: MREC/02/6/35).
Study design
Randomised double-blind placebo controlled parallel group study
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
GP practices
Trial type
Not Specified
Patient information sheet
Condition
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 names
Ginkgo extract
Primary outcome measure
Alzheimer's Disease Assessment Scale Cognitive Subscale (ADAS-cog) at six months.
Secondary outcome measures
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)
Overall trial start date
01/04/2003
Overall trial end date
31/12/2005
Reason abandoned (if study stopped)
Eligibility
Participant 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
Participant type
Patient
Age group
Senior
Gender
Both
Target number of participants
Target: 200
Participant exclusion criteria
1. Commencement of acetylcholinesterase therapy within two months of recruitment
2. Current anticoagulant therapy
3. Abnormal clotting profile
Recruitment start date
01/04/2003
Recruitment end date
31/12/2005
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Senior Lecturer
London
W10 6DZ
United Kingdom
Sponsor information
Organisation
Alzheimer's Society (UK)
Sponsor details
Gordon House
10 Greencoat Place
London
SW1P 1PH
United Kingdom
+44 (0)20 7306 0606
enquiries@alzheimers.org.uk
Sponsor type
Charity
Website
Funders
Funder type
Charity
Funder name
Alzheimer's Society (UK)
Alternative name(s)
Funding Body Type
unknown
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)
Publication list
Results in: http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=17608932
Publication citations
-
Results
McCarney R, Warner J, Iliffe S, van Haselen R, Griffin M, Fisher P, The Hawthorne Effect: a randomised, controlled trial., BMC Med Res Methodol, 2007, 7, 30, doi: 10.1186/1471-2288-7-30.