Status: Ongoing
First registered on:
09/11/2015
Last updated on:
18/12/2018
1. Study identification
EU PAS Register NumberEUPAS8705
Official titleBenzodiazepine and anticholinergic use and incident dementia
Study title acronymABCD study
Study typeObservational study
Brief description of the studyIn this study we will examine whether the use of benzodiazepines, non-benzodiazepine derivates and medications with anticholinergic activity increase the risk of dementia. We will also examine whether the risk persists or is reduced once the medication is stopped.
We will identify CPRD patients who, since April 2006, were diagnosed with dementia aged 65-99 years. We will compare the medication history of each patient with dementia to that of 7 matched patients without dementia. We will compare the use and dosage of medications prescribed during the period before dementia diagnosis, whilst controlling for other health and social differences.
Was this study requested by a regulator?No
Is the study required by a Risk Management Plan (RMP)?
Not applicable
Regulatory procedure number (RMP Category 1 and 2 studies only)
Other study registration identification numbers and URLs as applicable
2. Research centres and Investigator details
Coordinating study entity
Centre nameUniversity of East Anglia
Centre locationNorwich, UK
Details of (Primary) lead investigator
Title Dr
Last name George
First name Savva
Is this study being carried out with the collaboration of a research network?
No
Other centres where this study is being conducted
Not applicable (single centre)
Countries in which this study is being conducted
National study
United Kingdom
3. Study timelines: initial administrative steps, progress reports and final report
PlannedActual
Date when funding contract was signed30/06/2014
Start date of data collection03/07/2015
Start date of data analysis24/08/201526/10/2015
Date of interim report, if expected
Date of final study report30/09/2018
4. Sources of funding
Please provide estimates of the percentage of funding by source for this study
Names(s)Approximate % funding
Pharmaceutical companies
CharitiesAlzheimer's Society100
Government body
Research councils
EU funding scheme
5. Contact details for enquiries
Scientific Enquiries
Title Dr
Last name Richardson
First name Kathryn
Address line 1School of Health Sciences
Address line 2The Queen's Building
Address line 3University of East Anglia
CityNorwich
PostcodeNR4 7TJ
CountryUnited Kingdom
Phone number (incl. country code)441603591070
Alternative phone number
Fax number (incl. country code)
Public Enquiries
Title Dr
Last name George
First name Savva
Address line 1School of Health Sciences
Address line 2Edith Cavell Building
Address line 3University of East Anglia
CityNorwich
PostcodeNR4 7TJ
CountryUnited Kingdom
Phone number (incl. country code)441603597091
Alternative phone number
Fax number (incl. country code)
6. Study drug(s) information
Substance class (ATC Code)N05BA (Benzodiazepine derivatives)
Substance class (ATC Code)N05CD (Benzodiazepine derivatives)
Substance class (ATC Code)N05CF (Benzodiazepine related drugs)
Substance class (ATC Code)N04A (ANTICHOLINERGIC AGENTS)
7. Medical conditions to be studied
Medical condition(s)Yes
Dementia
8. Population under study
Age
Adults (65 - 74 years)
Adults (75 years and over)
Sex
Male
Female
9. Number of subjects
Estimated total number of subjects326000
Additional information
Estimated 40,770 dementia cases with 7 matched controls per case.
10. Source of data
Is this study being carried out with an established data source?Yes
Data sources registered with ENCePP
Sources of data
Routine primary care electronic patient registry
11. Scope of the study
What is the scope of the study?
Disease epidemiology
Risk assessment
Primary scope : Risk assessment
12. Main objective(s)
What is the main objective of the study?
1. To determine whether the use of benzodiazepines, non-benzodiazepine derivatives or medications with anticholinergic activity increases the risk of dementia, and whether risk increases with increased duration, dosage or concurrent use.
2. To determine whether these effects persist beyond medication cessation.
Are there primary outcomes?Yes
Dementia incidence
Are there secondary outcomes?No
13. Study design
What is the design of the study?
Case-control study
14. Follow-up of patients
Will patients be followed up?Not applicable/no follow-up
15. Data analysis plan
Please provide a brief summary of the analysis method
We will assess the association between benzodiazepine exposure, anticholinergic exposure and dementia using conditional logistic regression. Odds ratios (and 95% confidence intervals) will be provided unadjusted and adjusted for exposure to each class of medications with adverse cognitive effects and covariates.
The association between dementia and the primary exposure of DDDs will be examined, for (i) benzodiazepines, (ii) Z-drugs, and medications with (iii) possible, (iv) probable and (v) definite anticholinergic activity. The model will adjust for the covariates as well as the number of DDDs of the other medications with potential adverse cognitive effects.
The association between dementia and the following secondary exposures will be separately examined:
• Duration of prescriptions.
• Any prescription.
• For anticholinergics - average ACB sum and duration taking 3 or more possible anticholinergics concurrently.
16. ENCePP seal
Are you requesting the ENCePP seal for this study?
No
17. Full protocol
Not submitted
18. Study Results
Not submitted
Please list the 5 most relevant publications using data from your study
ReferenceLink to web-publication
19. Other relevant documents
Conflict(s) of interest of
investigator(s)Not submitted
Composition of Steering Group and
ObserversNot submitted
Other documentsNot
submitted
Signed Code of
Conduct Checklist
Not submitted
Signed Code of Conduct Declaration
Not submitted
Signed Checklist for Study
Protocols
Not submitted
