Condition category
Nervous System Diseases
Date applied
02/08/2002
Date assigned
02/08/2002
Last edited
11/07/2007
Prospective/Retrospective
Prospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

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 measures

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 Alzheimer’s 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

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

private sector organisation

Funding Body Subtype

professional associations and societies

Location

United Kingdom

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

Results - basic reporting

Publication summary

Results in: http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=17608932

Publication citations

  1. 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.

Additional files

Editorial Notes