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Status: Ongoing First registered on: 27/06/2019

Last updated on: 02/03/2021

1. Study identification

EU PAS Register NumberEUPAS29923

Official titleUtilisation of oral anticoagulants in older people with atrial fibrillation in UK general practice

Study title acronym

Study typeObservational study

Brief description of the studyAtrial fibrillation (AF) is a heart condition that increases the risk of stroke. Blood thinning tablets known as oral anticoagulants (OACs) help to reduce the risk of stroke and guidelines recommend that OACs are prescribed to people with AF who also have other risk factors for stroke such as heart failure, high blood pressure or diabetes. Vitamin K antagonists (VKAs), such as warfarin, were the only OACs available. VKAs are difficult to manage as they require frequent blood tests and regular dose changes, they also interact with lots of other medicines and food. Historically, VKAs have been under-used in older people due to concerns about patients managing the complex dosing schedule if they have cognitive impairment, and also the risk of brain bleeds if they fall. Direct oral anticoagulants (DOACs) were introduced as an alternative to VKAs in 2008 but were not licensed for stroke prevention in AF until 2011. It is not known whether the introduction of DOACs has changed the rates of OAC prescribing for older people (aged 75 years and over) or how patient demographics, other medical conditions and concomitant prescribing affect the choice of OAC prescribed in UK general practice. The objectives of the study are: 1. To describe changes in the point prevalence and incidence of OAC prescribing by year prior to the introduction of DOACs (2003-2007), between the introduction of DOACs and the time they were recommended as an option by the National Institute for Health and Clinical Care Excellence (NICE) for stroke prevention in AF (2008-2012), and following publication of NICE technology appraisals recommending DOACs (2013-2017). 2. To describe switching between OACs during the study period. 3. To compare the characteristics of patients with AF who were newly started on OACs during each period described in objective 1, to those not prescribed an OAC in the same period. 4. To describe persistence with DOACs compared with warfarin.

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 to which the investigator belongsUniversity of Bath

Department/Research groupPharmacy & Pharmacology

Organisation/affiliationUniversity of Bath

Website/Homepagewww.bath.ac.uk

Details of (Primary) lead investigator

Title Mrs

Last name Anneka

First name Mitchell

Is this study being carried out with the collaboration of a research network?

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 signed18/09/2018

Start date of data collection01/05/2019

Start date of data analysis30/07/201931/07/2019

Date of interim report, if expected

Date of final study report31/03/2021

4. Sources of funding

Please provide estimates of the percentage of funding by source for this study

Names(s)Approximate % funding

Pharmaceutical companies

CharitiesThe Dunhill Medical Trust100

Government body

Research councils

EU funding scheme

5. Contact details for enquiries

Scientific Enquiries

Title Mrs

Last name Anneka

First name Mitchell

Address line 1Dept. of Pharmacy & Pharmacology

Address line 2University of Bath

Address line 3Claverton Down

CityBath

PostcodeBA2 7AY

CountryUnited Kingdom

Phone number (incl. country code)44-1225-384215

Alternative phone number

Fax number (incl. country code)

Email address a.mitchell@bath.ac.uk

Public Enquiries

Title Mrs

Last name Anneka

First name Mitchell

Address line 1Dept. of Pharmacy & Pharmacology

Address line 2University of Bath

Address line 3Claverton Down

CityBath

PostcodeBA2 7AY

CountryUnited Kingdom

Phone number (incl. country code)44-1225-384215

Alternative phone number

Fax number (incl. country code)

Email address a.mitchell@bath.ac.uk

11. Scope of the study

What is the scope of the study?

Drug utilisation study

Primary scope : Drug utilisation study

12. Main objective(s)

What is the main objective of the study?

1) To describe changes in the point prevalence and incidence of OAC prescribing by year 2) To describe switching between OACs during the study period 3) To compare the characteristics of patients with AF who were newly started on OACs to those who weren't during 3 study periods: 2003-2007, 2008-2012, 2013-2017. 4) To describe persistence with DOACs compared with warfarin

Are there primary outcomes?No

Are there secondary outcomes?No

13. Study design

What is the design of the study?

Drug utilisation 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

Point prevalence of OAC prescribing will be calculated at the midpoint of each year. The incidence of OAC prescribing will be calculated overall and for each specific OAC. Everyone in the cohort will be considered 'at risk' until the time they receive their first OAC prescription. For the person-time at risk calculation the denominator will be truncated at the date of their first OAC prescription. Incidence will be stratified by age (75-84 and 85+) and sex. The number and percentage of patients switching OAC will be calculated. The number of patients with multiple switches and details of the switches will be described. Average time to switch will be reported. Demographics, characteristics, co-morbidities and concomitant medications will be reported for each period in the no OAC, DOAC and warfarin groups.Duration of prescribing of DOACs will be compared to warfarin using Cox-proportional hazards, stratified by DOAC and adjusted for age and other important covariates, if feasible.