An intervention study to improve food shopping and prevent cardiovascular disease among patients in primary care: the PC SHOP trial

ISRCTN ISRCTN14279335
DOI https://doi.org/10.1186/ISRCTN14279335
Secondary identifying numbers 12408
Submission date
01/09/2017
Registration date
21/09/2017
Last edited
06/04/2021
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Nutritional, Metabolic, Endocrine
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
Cardiovascular disease (CVD), including heart attacks and strokes, is the leading cause of death in the UK and is strongly influenced by diet. Eating too much saturated fat increases the amount of ‘bad’ LDL-cholesterol in the blood, which increases the risk of heart disease. Previous studies have shown that reducing the intake of saturated fat (mostly fats from animal sources such as butter or meat), by swapping some foods for others that are lower in saturated fat, can lead to big reductions in the amount of LDL-cholesterol. However, these studies have achieved success either by giving specific foods to people or by providing intensive support and advice from nutrition specialists.
The aim of this study is to develop and test the feasibility of a new intervention, involving brief oral and written advice from a health professional at the GP practice together with regular information on the saturated fat content of food purchases.

Who can participate?
Adults aged 18 and older with high LDL cholesterol.

What does the study involve?
A group of participants attend a single one-to-one appointment with a health professional where they are given advice on diet and motivations to reduce their intake of saturated fats. Another group receive the same appointment with the health professional and also receive a personalised monthly report with the nutrition and fat content on all purchases from Tesco at their follow up appointments.

What are the possible benefits and risks of participating?
Participants may benefit from receiving some information to help reduce their risk of cardiovascular disease and personalised advice on food purchases. Blood tests are also shared with participants and their GPs may contact them to arrange any further treatment they may need if a problem is detected. There are no direct risks with participating, however participants may experience bruising and discomfort when providing blood samples.

Where is the study run from?
University of Oxford (UK)

When is the study starting and how long is it expected to run for?
November 2017 to June 2019 (as of 02/10/2018)

Who is funding the study?
National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research & Care Oxford at Oxford Health NHS Foundation Trust (UK) and The National Institute for Health Research (NIHR) School for Primary Care Research.

Who is the main contact?
Dr Carmen Piernas Sanchez

Contact information

Dr Carmen Piernas Sanchez
Scientific

Radcliffe Primary Care
Radcliffe Observatory Quarter
Woodstock Road
Oxford
OX26GG
United Kingdom

ORCiD logoORCID ID 0000-0002-7536-922X
Phone +44 (0)1865 289284
Email carmen.piernas-sanchez@phc.ox.ac.uk

Study information

Study designCurrent study design as of 08/02/2019: Interventional single centre individually randomised 3 arm parallel group trial followed by a qualitative study Previous study design: Interventional single centre individually randomised 3 arm parallel group trial
Primary study designInterventional
Secondary study designRandomised parallel trial
Study setting(s)GP practice
Study typePrevention
Participant information sheet Our PIS can be downloaded from this website: https://www.clahrc-oxford.nihr.ac.uk/Research/Primary-Care-Shopping-Intervention-for-Cardiovascular-Disease-Prevention
Scientific titlePrimary Care Shopping Intervention for Cardiovascular Disease Prevention
Study acronymPC SHOP
Study objectivesStudy aim:
This project aims to develop and test a behavioural intervention to promote reductions in saturated fat (SFA) intake among patients in primary care with raised LDL-cholesterol who are willing to change their diet.

Hypothesis:
Compared to usual care, an intervention involving health professional advice alone and/or in combination with personalised feedback and monitoring on the SFA content of food purchases, will help people reduce dietary SFA intake which, in the longer term, would be expected to lead to reductions in LDL cholesterol.
Ethics approval(s)South Central Oxford C Research Ethics Committee, 12/05/2017, ref: 17/SC/0168, IRAS project ID 214999
Health condition(s) or problem(s) studiedAdults with high LDL cholesterol
InterventionCurrent interventions, as of 08/02/2019:
In the main trial participants are randomly allocated to either a control or intervention group.
Intervention 1: Brief advice session
This intervention consists of a single one-to-one appointment with the health professional (HP) in which they will receive advice on the importance of dietary change and motivation to reduce SFA based on the British Heart Foundation “Cut the Saturated Fat” chart, which will be provided as printed educational material. This session is aimed to inform participants about the benefits of saturated fat reduction and encourage them to attempt it. Dietary advice is particularly focused on explaining the different sources of fat and the most appropriate changes proposed in the BHF guidance to decrease SFA, primarily by substitution with lower SFA options (e.g. change from regular beef to lean beef); or with mono- and polyunsaturated fat sources (e.g. change from butter to low-fat vegetable spread).
Intervention 2: Brief advice session and shopping report
In addition to the brief advice session detailed above, participants in this intervention arm receive a personalised report with the nutritional composition of foods and beverages purchased from Tesco over the last three months (baseline) and subsequent months (monthly over the three months of follow up). This report includes information on total energy (calories) and saturated fat as a % of total energy, and the major food contributors to SFA. Participants receive monthly reports to allow them to chart their progress in reducing SFA in their grocery purchases. This information is accompanied by a list with suggestions for one-for-one swaps for foods high in SFA for lower SFA foods to support dietary change.
Control group
Participants in the control group (usual care) are recruited into the study and will be informed by post of their elevated risk and their blood tests by the study team. They are then seen again at three months for collecting outcome measures.

Following the main trial, a qualitative study will be conducted with a sub-sample of participants from the intervention 2 arm.
A semi-structured, one-to-one, 30-minute telephone interview will be conducted to explore issues related to food purchasing behaviours, including knowledge, perceived barriers, facilitators and actions, contextual influences, and value of the healthcare advice provided.

Previous interventions:
Participants are randomly allocated to either a control or intervention group.

Intervention 1: Brief advice session
This intervention consists of a single one-to-one appointment with the health professional (HP) in which they will receive advice on the importance of dietary change and motivation to reduce SFA based on the British Heart Foundation “Cut the Saturated Fat” chart, which will be provided as printed educational material.

This session is aimed to inform participants about the benefits of saturated fat reduction and encourage them to attempt it. Dietary advice is particularly focused on explaining the different sources of fat and the most appropriate changes proposed in the BHF guidance to decrease SFA, primarily by substitution with lower SFA options (e.g. change from regular beef to lean beef); or with mono- and polyunsaturated fat sources (e.g. change from butter to low-fat vegetable spread).

Intervention 2: Brief advice session and shopping report
In addition to the brief advice session detailed above, participants in this intervention arm receive a personalised report with the nutritional composition of foods and beverages purchased from Tesco over the last three months (baseline) and subsequent months (monthly over the three months of follow up). This report includes information on total energy (calories) and saturated fat as a % of total energy, and the major food contributors to SFA. Participants receive monthly reports to allow them to chart their progress in reducing SFA in their grocery purchases. This information is accompanied by a list with suggestions for one-for-one swaps for foods high in SFA for lower SFA foods to support dietary change.

Control group
Participants in the control group (usual care) are recruited into the study and will be informed by post of their elevated risk and their blood tests by the study team. They are then seen again at three months for collecting outcome measures.
Intervention typeBehavioural
Primary outcome measureChange in SFA intake is measured using the 2 x 24h dietary recalls using the Web-Q instrument at baseline and 3 months (follow up).
Secondary outcome measuresCurrent secondary outcome measures, as of 08/02/2019:
1. Changes in SFA from total purchases and the proportion of food items with low SFA (e.g. products with ≤1.5 grams of SFA per 100 grams of the product) is measured using purchasing records obtained from the supermarket at baseline and 3 months (follow up).
2. Changes in LDL-cholesterol, HDL-cholesterol, total cholesterol and triglycerides is measured using blood samples taken at baseline and 3 months (follow up).
3. Changes in energy intake, total fat, total sugars, fibre and salt; and high SFA food groups (updated 19/03/2018) is measured using 2x24h dietary recalls using the Web-Q instrument at baseline and 3 months (follow up).
4. Changes in energy density, total fat, sugar, fibre and salt from purchases is measured using purchasing records obtained from the supermarket at baseline and 3 months (follow up).
5. Changes in systolic and diastolic blood pressure is measured using an electronic blood pressure monitors at baseline and 3 months (follow up).
6. Changes (absolute (kg) and relative (%)) in body weight is measured using a calibrated electronic platform scale at baseline and 3 months (follow up).
7. Feasibility and process measures:
7.1. Willingness of participants to take part in the study and be randomised is measured using recruitment rates at baseline.
7.2. Programme attendance and retention is measured using follow up and completion rates at 3 months.
7.3. Acceptability of the intervention for participants and health professionals; uptake of knowledge, motivation and swaps accepted is measured using non validated questionnaires at baseline and 3 months (follow up).
8. Issues related to food purchasing behaviours, including knowledge, perceived barriers, facilitators and actions, contextual influences, and value of the healthcare advice provided measured using thematic analysis (framework method) of participant interviews conducted in a subset of participants after follow-up.

Previous secondary outcome measures:
1. Changes in SFA from total purchases and the proportion of food items with low SFA (e.g. products with ≤1.5 grams of SFA per 100 grams of the product) is measured using purchasing records obtained from the supermarket at baseline and 3 months (follow up).
2. Changes in LDL-cholesterol, HDL-cholesterol, total cholesterol and triglycerides is measured using blood samples taken at baseline and 3 months (follow up).
3. Changes in energy intake, total fat, total sugars, fibre and salt; and high SFA food groups (updated 19/03/2018) is measured using 2x24h dietary recalls using the Web-Q instrument at baseline and 3 months (follow up).
4. Changes in energy density, total fat, sugar, fibre and salt from purchases is measured using purchasing records obtained from the supermarket at baseline and 3 months (follow up).
5. Changes in systolic and diastolic blood pressure is measured using an electronic blood pressure monitors at baseline and 3 months (follow up).
6. Changes (absolute (kg) and relative (%)) in body weight is measured using a calibrated electronic platform scale at baseline and 3 months (follow up).
7. Feasibility and process measures:
7.1. Willingness of participants to take part in the study and be randomised is measured using recruitment rates at baseline.
7.2. Programme attendance and retention is measured using follow up and completion rates at 3 months.
7.3. Acceptability of the intervention for participants and health professionals; uptake of knowledge, motivation and swaps accepted is measured using non validated questionnaires at baseline and 3 months (follow up).
Overall study start date01/06/2016
Completion date30/09/2019

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants112
Total final enrolment113
Key inclusion criteriaCurrent participant inclusion criteria, as of 08/02/2019:
Main study:
1. Participant is willing and able to give informed consent for participation in the study
2. Male or Female, aged 18 years or above
3. With confirmed LDL cholesterol above 3 mmol/L at recruitment
4. Express a desire for support to improve the nutritional quality of their diet to reduce their CVD risk
5. Primarily responsible for household shopping (e.g. complete at least half of their household shopping)
6. Shops mainly at Tesco (e.g. at least once/week instore and/or online) using a Tesco’s storecard. They need to have had a Tesco’s storecard for at least 3 months before recruitment
7. Computer literate

Screening criteria:
1. Age ≥18 years with a blood test in the GP records which indicate LDL-cholesterol >3.5 mmol/L or total cholesterol >5.5 mmol/L in the past 24 months
2. Who will likely benefit from a lower SFA diet with no pre-existing conditions that warrant exclusion.

Qualitative study:
1. Participated in intervention 2 arm (brief advice plus shopping advice) of the PC-SHOP study
2. Willing to be interviewed

Previous participant inclusion criteria:
1. Participant is willing and able to give informed consent for participation in the study
2. Male or Female, aged 18 years or above
3. With confirmed LDL cholesterol above 3 mmol/L at recruitment
4. Express a desire for support to improve the nutritional quality of their diet to reduce their CVD risk
5. Primarily responsible for household shopping (e.g. complete at least half of their household shopping)
6. Shops mainly at Tesco (e.g. at least once/week instore and/or online) using a Tesco’s storecard. They need to have had a Tesco’s storecard for at least 3 months before recruitment
7. Computer literate

Screening criteria:
1. Age ≥18 years with a blood test in the GP records which indicate LDL-cholesterol >3.5 mmol/L or total cholesterol >5.5 mmol/L in the past 24 months
2. Who will likely benefit from a lower SFA diet with no pre-existing conditions that warrant exclusion.
Key exclusion criteriaCurrent exclusion criteria, as of 19/03/2018:
1. Unable to read and understand the instructions provided in English
2. Pregnant, or planning to become pregnant during the course of the study
3. Planned or likely changes to cholesterol-lowering medication
4. Existing or recent cardiovascular conditions: heart attack or stroke within the last 3 months, heart failure of grade II New York Heart Association and more severe, or prolonged QT syndrome, angina, arrhythmia or atrial fibrillation
5. Familial hyperlipidaemia
6. Currently or recently (within the last 3 months) participating in another intervention study which likely affects the outcomes measured in this study.
7. Patients that the GP judges not able to meet the demands of the study or unlikely to adhere to study procedures as stated in the protocol

Previous exclusion criteria:
1. Unable to read and understand the instructions provided in English
2. Pregnant, or planning to become pregnant during the course of the study
3. Planned or likely changes to cholesterol-lowering medication
4. Existing or recent cardiovascular conditions: heart attack or stroke within the last 3 months, heart failure of grade II New York Heart Association and more severe, or prolonged QT syndrome, angina, arrhythmia or atrial fibrillation
5. Familial hyperlipidaemia
6. Currently or recently (within the last 3 months) participating in another study
7. Patients that the GP judges not able to meet the demands of the study or unlikely to adhere to study procedures as stated in the protocol
Date of first enrolment21/03/2018
Date of final enrolment01/06/2019

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

University of Oxford
Nuffield Department of Primary Care Health Sciences
University of Oxford
Radcliffe Primary Care Building
Radcliffe Observatory Quarter
Woodstock Road
Oxford
OX2 6GG
United Kingdom

Sponsor information

University of Oxford
University/education

Clinical Trials and Research Governance
Churchill Hospital
Headington
Oxford
OX37LE
England
United Kingdom

Phone +44 (0)1865572221
Email heather.house@admin.ox.ac.uk
ROR logo "ROR" https://ror.org/052gg0110

Funders

Funder type

Government

National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research & Care Oxford at Oxford Health NHS Foundation Trust

No information available

The National Institute for Health Research (NIHR) School for Primary Care Research

No information available

Results and Publications

Intention to publish date05/11/2020
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryData sharing statement to be made available at a later date
Publication and dissemination planThe investigators within the central research team will be involved in reviewing drafts of the manuscripts, abstracts, press releases and any other publications arising from the study. The main paper reporting the primary outcome will also include data on the secondary outcomes. Other qualitative outcomes, including acceptability of the intervention, may be reported in additional papers.
The trial results will be published and all who meet the criteria for authorship will be listed as authors. Authorship will be determined in accordance with the ICMJE guidelines and other contributors will be acknowledged.

We will submit the paper to NIHR for approval before submission.
IPD sharing planThe data sharing plans for the current study are unknown and will be made available at a later date.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Statistical Analysis Plan version v1.0 06/03/2019 No No
Statistical Analysis Plan version v2.0 01/04/2019 01/04/2019 No No
Protocol article protocol 15/04/2019 16/04/2020 Yes No
Results article results 05/11/2020 12/03/2021 Yes No
Results article qualitative results 31/03/2021 06/04/2021 Yes No
HRA research summary 28/06/2023 No No

Additional files

ISRCTN14279335_SAP_v1.0 06Mar19.pdf
ISRCTN14279335_SAP_v2.0_1Apr19.pdf
Uploaded 01/04/2019.

Editorial Notes

06/04/2021: Publication reference added.
12/03/2021: The following changes have been made:
1. Publication reference added.
2. The total final enrolment number has been added from the reference.
23/10/2020: The intention to publish date was changed from 31/12/2020 to 05/11/2020.
11/06/2020: The intention to publish date was changed from 31/12/2019 to 31/12/2020.
16/04/2020: Publication reference added.
01/04/2019: Uploaded statistical analysis plan.
11/03/2019: Uploaded statistical analysis plan.
08/02/2019: The following updates were made:
1. The overall trial end date was changed from 31/12/2018 to 30/09/2019
2. The interventions were updated
3. The study design was updated
4. The secondary outcome measures were updated
5. The participant inclusion criteria were updated
6. The recruitment start date was corrected from 21/03/2017 to 21/03/2018
7. The recruitment end date was changed from 10/10/2018 to 01/06/2019
08/11/2018: The intention to publish date was changed from 01/01/2019 to 31/12/2019.
02/10/2018: The following updates were made:
1. The plain English summary was updated
2. The recruitment start date was updated from 01/11/2017 to 21/03/2017
3. The recruitment end date was updated from 31/08/2018 to 10/10/2018
19/03/2018: The following updates were made:
1. The recruitment end date was changed from 01/02/2018 to 31/08/2018
2. Secondary outcome measure 3 was updated from:
Changes in energy intake, total fat, total sugars, fibre and salt is measured using 2x24h dietary recalls using the Web-Q instrument at baseline and 3 months (follow up) to Changes in energy intake, total fat, total sugars, fibre and salt; and high SFA food groups measured using 2x24h dietary recalls using the Web-Q instrument at baseline and 3 months (follow up).
3.Exclusion criteria was updated
4. NIHR SPCR (School of Primary Care Research) was added as an additional funder.
22/09/2017: Internal review