Understanding adherence to blood pressure treatment and statins

ISRCTN ISRCTN83535288
DOI https://doi.org/10.1186/ISRCTN83535288
IRAS number 200751
Secondary identifying numbers 38504, IRAS 200751
Submission date
09/12/2019
Registration date
14/01/2020
Last edited
01/02/2024
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Circulatory System
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English Summary

Background and study aims
High blood pressure (hypertension) is the largest contributor to global mortality and a major risk factor for heart disease and stroke. About 30% of the UK population suffer from hypertension.
A direct association has been found between survival and adherence to medication for high blood pressure (statin therapy). However, medication adherence is a significant problem with around 50% of patients with cardiovascular disease or its major risk factors not regularly taking their medications (adherence) one year after starting treatment.

The aim of this research is to assess adherence to high blood pressure and statin medication in a UK population through direct (urine testing) and self-report measures (questionnaire). These results can be combined with data from a survey we have designed and validated, to identify psychological barriers and facilitators to adherence. The findings will inform the design and deployment of new interventions based on behavioural science to improve adherence and thus patient outcomes.

Who can participate?
Patients at the GP surgery who are taking statins, or medication for high blood pressure

What does the study involve?
Taking part in the study will involve providing a small amount of personal information, most of which is collected routinely by the doctor. Participants will be asked to give a urine sample to check if the medicines prescribed are having the expected effect. Finally, participants will complete a simple questionnaire which will ask about experiences of taking blood pressure medications or statins and reasons why this may be difficult or easy. This will take approximately 20 minutes to complete. If necessary, medical notes may be accessed by members of the research team to check certain details.

What are the possible benefits and risks of participating?
There are no direct benefits but the study will allow us to design ways to help people to take their medications and improve their blood pressure or cholesterol control in the future.
Taking part in the study involves providing a minimal amount of personal information, giving a urine sample and answering a simple questionnaire. There is no reasonable expectation that any harm will arise from this.

Where is the study run from?
Imperial College Healthcare NHS Trust, UK

When is the study starting and how long is it expected to run for?
April 2016 to January 2023

Who is funding the study?
1. Robert Luff Foundation, UK
2. NIHR Imperial Patient Safety Translational Research Centre, UK

Who is the main contact?
Dr Gaby Judah
g.judah@imperial.ac.uk

Contact information

Dr Gaby Judah
Scientific

Imperial College London
10th Floor, QEQM Building
St Mary's Hospital
Praed Street
London
W2 1NY
United Kingdom

Phone +44 (0)203 3121962
Email g.judah@imperial.ac.uk
Prof Peter Server
Scientific

Imperial College London - Hammersmith Campus
Imperial College Translational and Experimental Medicine Building (ICTEM)
National Heart and Lung Institute (NHLI)
Du Cane Road
London
W12 0NN
United Kingdom

ORCiD logoORCID ID 0000-0003-0421-2409
Phone +44 (0)207 594 1099
Email p.sever@imperial.ac.uk
Dr David Wingfield
Scientific

Brook Green Medical Centre
Bute Gardens
Hammersmith
London
W6 7EG
United Kingdom

ORCiD logoORCID ID 0000-0001-5331-0684
Phone +44 (0)207 471 3333
Email d.wingfield@imperial.ac.uk

Study information

Study designObservational; Design type: Cross-sectional
Primary study designObservational
Secondary study designCross sectional study
Study setting(s)Other
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details to request a patient information sheet
Scientific titleUnderstanding the psychological determinants of medication adherence in patients taking anti-hypertensive and statin medication in the United Kingdom
Study hypothesisCurrent study hypothesis as of 29/01/2020:
Research questions:
- What is the self-reported and objectively measured rate of anti-hypertensive and statin medication non-adherence in a UK patient population?
- What are the psychological barriers to medication adherence?
- What are the psychological facilitators of medication adherence?
- Can identified psychological constructs be used to predict medication non-adherence?
_____
Previous study hypothesis:
Research questions:
- What is the self-reported and objectively measured rate of anti-hypertensive and statin medication non-adherence in a UK patient population?
- What are the psychological and behavioural barriers to medication adherence?
- What are the psychological and behavioural facilitators of medication adherence?
- Can identified behavioural and psychological constructs be used to predict medication non-adherence?
Ethics approval(s)Approved 10/03/2016, East Midlands - Derby Research Ethics Committee (The Old Chapel, Royal Standard Place, Nottingham, NG1 6FS; +44(0)207 104 8036; NRESCommittee.EastMidlands-Derby@nhs.net), ref: 16/EM/0106
ConditionHypertension
InterventionCurrent interventions as of 29/01/2020:
The research project takes place in three distinct but linked phases - each of which will be conducted at a different time sequentially and involve a different cohort of patients from the study population.

1) Semi-structured interviews - formalised semi-structured interviews of patients attending the Peart Rose clinic will be performed. Whilst the focus will be on allowing patients to freely express their experience of taking medication, a structured topic guide will be used to direct the interviews as required to help elicit barriers and facilitators of adherence. Patients will be recruited until saturation (<10% statement duplication), which from previous similar studies is likely to be approximately 15 patients. The interviews will be analysed thematically to guide questionnaire item generation in conjunction with an appropriate literature review. Each interview will take approximately 20 mins.

2) Questionnaire design and piloting - following analysis of the semi-structured interviews and a thorough systematic literature review questionnaire items will be generated and constructively aligned to the validated Health Belief Model and Theoretical Domains Framework of behaviour. The pilot questionnaire will then be tested on a sample patient population of 30 patients and subsequently refined via calculation of ceiling and floor effects, inter-item correlation and Cronbach’s Alpha internal consistency measures. The pilot questionnaire items will also be assessed for readability and comprehensibility using a validated method to ensure it is appropriate for the target
population. Completion of the pilot questionnaire will take approximately 15 minutes and recruitment of participants will be from the same population and via the same methodology as will be adopted with the final definitive questionnaire study.

3) Principal data collection and testing - in order to validate the new questionnaire, and to assess the association between medication adherence and its’ psychological determinants approximately 500 patients from primary care will be recruited into a cross-sectional evaluative study (approximately 300 patients taking antihypertensives and 200 patients taking statins). Participants will complete the questionnaire which will include routine demographic information including age, sex, martial status, co-morbidities, medication history and socio-economic metrics. Participants will also be asked to complete validated measures of self-reported medication adherence (Extent of nonadherence scale) and habit (Self-Report Behavioural Automaticity Index (SRBAI)). Patients will also be asked to give urine samples to allow objective measurement of medication adherence within the past 24 hours, which can be used to help validate the self-report measure.

All results will then be assimilated and appropriately analysed prior to publication and dissemination - hopefully providing a new validated questionnaire for assessing barriers to medication adherence in a UK secondary care hypertensive population, together with providing evidence for development of a short assessment tool and further studies in other patient populations e.g. General Practice.
_____
Previous interventions:
The research project takes place in three distinct but linked phases - each of which will be conducted at a different time sequentially and involve a different cohort of patients from the study population.

1) Semi-structured interviews - formalised semi-structured interviews of patients attending the Peart Rose clinic will be performed. Whilst the focus will be on allowing patients to freely express their experience of taking medication, a structured topic guide will be used to direct the interviews as required to help elicit barriers and facilitators of adherence. Patients will be recruited until saturation (<10% statement duplication), which from previous similar studies is likely to be approximately 15 patients. The interviews will be analysed thematically to guide questionnaire item generation in conjunction with an appropriate literature review. Each interview will take approximately 20 mins.

2) Questionnaire design and piloting - following thematic analysis of the semi-structured interviews and a thorough systematic literature review questionnaire items will be generated and constructively aligned to the validated Health Belief Model and Theoretical Domains Framework of behaviour. The pilot questionnaire will then be tested on a sample patient population of 30 patients and subsequently refined via calculation of ceiling and floor effects, inter-item correlation and Cronbach’s Alpha internal consistency measures. The pilot questionnaire items will also be assessed for readability and comprehensibility using a validated method to ensure it is appropriate for the target
population. Completion of the pilot questionnaire will take approximately 15 minutes and recruitment of participants will be from the same population and via the same methodology as will be adopted with the final definitive questionnaire study.

3) Principal data collection and testing - in order to validate the new questionnaire, and to assess the association between medication adherence and its’ behavioural and psychological determinants approximately 200 patients from the Peart Rose Hypertension Clinic will be recruited into a cross-sectional evaluative study. During routine clinic attendance participants will complete the questionnaire. In addition routine demographic information including age, sex, martial status, co-morbidities, medication history and socio-economic metrics will be collected. Participants will also be asked to complete validated measures of self-reported medication adherence (Moresby Medication Adherence Scale (MMAS-8), and the Self-Report Behavioural Automaticity Index (SRBAI)) in order to aid in the validation of the new questionnaire. Patients give urine samples on a regular basis as part of their routine care in the clinic; results of direct measures of medication adherence will be collected and utilised to validate the questionnaire.

All results will then be assimilated and appropriately analysed prior to publication and dissemination - hopefully providing a new validated questionnaire for assessing medication adherence in a UK secondary care hypertensive population, together with providing evidence for development of a short assessment tool and further studies in other patient populations e.g. General Practice.
Intervention typeOther
Primary outcome measureMeasured during the data collection session:
1. Urine test of medication adherence. A urine sample will be tested for anti-hypertension and statin metabolites to give a valid and reliable direct measure of medication adherence within the past 24hrs.
2. Self-reported medication adherence. Using 3 item Likert scale from Voils 2012
Secondary outcome measuresMeasured during the data collection session:
1. Habit, measured using the Self Report Automaticity Index, a 4-item Likert scale from Gardner 2012
Overall study start date10/12/2015
Overall study end date31/01/2023

Eligibility

Participant type(s)Patient
Age groupAdult
SexBoth
Target number of participantsPlanned Sample Size: 450; UK Sample Size: 450
Total final enrolment491
Participant inclusion criteriaCurrent inclusion criteria as of 29/01/2020:
All patients attending a primary or secondary care service for the treatment of hypertension or taking statins that are willing to take part
_____
Previous inclusion criteria:
All patients attending a primary or secondary care service for the treatment of hypertension that are willing to take part
Participant exclusion criteriaIn the opinion of the investigator unsuitable or unable to adequately complete questionnaire e.g. due to inadequate level of English comprehension
Recruitment start date27/04/2016
Recruitment end date31/05/2022

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

St. Mary's Hospital
Imperial College Healthcare NHS Trust
Praed Street
London
W2 1NY
United Kingdom

Sponsor information

Imperial College London
University/education

Research Governance Office
Room 221, Level 2, Medical School Building
Norfolk Place
London
W2 1PG
England
United Kingdom

Phone +44 (0)207 5941862
Email r.nicholson@imperial.ac.uk
Website http://www.imperial.edu/
ROR logo "ROR" https://ror.org/041kmwe10

Funders

Funder type

Charity

Robert Luff Foundation
Private sector organisation / Trusts, charities, foundations (both public and private)
Location
United Kingdom
National Institute for Health Research
Government organisation / National government
Alternative name(s)
National Institute for Health Research, NIHR Research, NIHRresearch, NIHR - National Institute for Health Research, NIHR (The National Institute for Health and Care Research), NIHR
Location
United Kingdom
Imperial College London
Government organisation / Universities (academic only)
Alternative name(s)
Imperial College of Science, Technology and Medicine, Imperial College London, UK, Imperial College London, London, England, Imperial College London in United Kingdom, imperialcollege, ICL
Location
United Kingdom

Results and Publications

Intention to publish date31/03/2024
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryAvailable on request
Publication and dissemination planPlanned publication in a high-impact peer-reviewed journal
IPD sharing planThe datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. Following the publication of the results, the anonymised datasets generated by the study will be available on request from Gaby Judah (g.judah@imperial.ac.uk). Any requests for data access will be considered by the study management team including discussion of the proposed use of the data, and storage of the data.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Protocol file version V1.7 06/08/2019 14/01/2020 No No
HRA research summary 28/06/2023 No No
Basic results 01/02/2024 01/02/2024 No No

Additional files

ISRCTN83535288_PROTOCOL_V1.7_06Aug2019.pdf
Uploaded 14/01/2020
ISRCTN83535288_BasicResults_01Feb24.pdf

Editorial Notes

01/02/2024: Basic results uploaded.
24/03/2023: The following changes have been made:
1. The total final enrolment was added.
2. The overall trial end date has been changed from 31/10/2022 to 31/01/2023 and the plain English summary updated accordingly.
3. The intention to publish date has been changed from 31/03/2023 to 31/03/2024.
14/07/2022: The following changes have been made:
1. Recruitment had resumed.
2. The recruitment end date has been changed from 31/01/2021 to 31/05/2022.
3. The overall trial end date has been changed from 31/05/2022 to 31/10/2022 and the plain English summary updated accordingly.
4. The intention to publish date has been changed from 30/11/2022 to 31/03/2023.
09/06/2021: The following changes have been made:
1. The overall trial end date has been changed from 30/06/2021 to 31/05/2022 and the plain English summary has been updated to reflect this change.
2. The intention to publish date has been changed from 30/06/2021 to 30/11/2022.
11/06/2020: The following changes were made to the trial record:
1. The publication and dissemination plan was changed.
2. The participant level data was changed from "to be made available at a later date" to "available on request".
04/05/2020: Due to current public health guidance, recruitment for this study has been paused.
29/01/2020: The following changes were made to the trial record:
1. The hypothesis was changed.
2. The interventions were changed.
3. The inclusion criteria were changed.
14/01/2020: Uploaded protocol Version 1.7, 6 August 2019 (not peer reviewed).
09/12/2019: Trial’s existence confirmed by National Institute for Health Research (NIHR).