People regulating themselves to achieve weight loss (Prevail Trial)
| ISRCTN | ISRCTN14148239 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN14148239 |
| Secondary identifying numbers | 11/2018 |
- Submission date
- 29/11/2018
- Registration date
- 13/12/2018
- Last edited
- 03/11/2020
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Nutritional, Metabolic, Endocrine
Plain English Summary
Background and study aims
This study tests a newly developed weight loss intervention that aims to make daily self-weighing a more effective tool for weight loss. The intervention guides participants through a self-regulation process after self-weighing: participants will be asked to track their weight measurements using a weight loss tracker. They will receive daily questionnaires asking them to plan a weight loss action for each day. On a weekly basis they will be asked to reflect on how their behaviours might explain their weight change and to evaluate the weight loss actions they used throughout the week.
Who can participate?
People aged 18 or over with a Body Mass Index (BMI) of 30 kg/m2 or over
What does the study involve?
Participants are randomly allocated to the treatment group or the control group. In the treatment group participants receive the new intervention, in the control group they are asked to simply weigh themselves daily. Participants attend two meetings with the research team, one at the start of the study and one at follow-up. At the first meeting participants, weight, height and body composition are measured. They also complete a questionnaire asking for their demographic background and previous experiences of weighing themselves. They then follow the assigned intervention for 8 weeks. After completing the intervention, participants in the treatment group receive a questionnaire by email asking about their opinions on the intervention components. At the follow-up meeting participants' weight and body composition are measured again. The changes in weight and body composition are compared across the control and treatment groups to see whether the treatment group lost more weight. Some participants in the intervention group are interviewed about their experiences in the study.
What are the possible benefits and risks of participating?
Everyone taking part in the study will receive an intervention that has the potential to help with losing weight. Everybody will also receive information about how to weigh oneself in the best way to achieve reliable results. Participants will be sent a lay summary of the results after analysis is completed. Daily weighing carries no specific health risks. Recent studies have shown that self-weighing leads to higher body satisfaction as well as decreases in depression levels. The researchers are therefore confident that self-weighing does not pose a risk for our participants. However, they realise that there is a theoretical risk that people with eating disorders might be adversely affected by daily weight measurements. They therefore decided to exclude this population group from the study.
Where is the study run from?
Nuffield Department of Primary Care Health Sciences (UK)
When is the study starting and how long is it expected to run for?
March 2018 to June 2019
Who is funding the study?
NIHR CLAHRC Oxford (UK)
Who is the main contact?
Kerstin Frie
kerstin.frie@phc.ox.ac.uk
Contact information
Scientific
Nuffield Department of Primary Care Health Sciences
University of Oxford
Gibson Building
Radcliffe Observatory Quarter
Woodstock Road
Oxford
OX2 6GG
United Kingdom
 ORCID ID |
0000-0002-4717-5874 |
|---|---|
| Phone | +44 (0)1865289317 |
| kerstin.frie@phc.ox.ac.uk |
Study information
| Study design | Single-centre individually randomised open two-arm parallel-group design |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised controlled trial |
| Study setting(s) | Home |
| Study type | Treatment |
| Participant information sheet | Please contact us via email to request a participant information sheet |
| Scientific title | A proof of concept trial of a self-regulation intervention for weight loss |
| Study acronym | PREVAIL |
| Study hypothesis | A behavioural intervention that guides users through a self-regulation process following self-weighing is more effective for weight loss than simple daily weighing. |
| Ethics approval(s) | NHS Health Research Authority, 20/11/2018, REC ref: 18/SC/0482 |
| Condition | Obesity |
| Intervention | All eligible participants will be randomised with an allocation ratio of 1:1 to the self-regulation intervention or control group after consent has been taken. A randomisation sequence, stratified by GP and using stratified block randomisation with randomly varying block sizes of 2 and 4 will be generated using a computer algorithm at http://www.randomization.com. Allocations will be concealed in numbered, sealed envelopes by an independent researcher in the department and handed to the researcher who will conduct the baseline visit with the participants. Participants in the treatment group will be guided through a self-regulation process following self-weighing for eight weeks. Participants will be asked to weigh themselves every day using provided standard body scales and keep track of their weight loss progress using a freely available weight-tracking app. They will be sent automated daily self-regulation prompts via email using the online software Qualtrics. The prompt will ask participants to plan a specific weight loss action for the day (e.g. do not eat between meals). They will be asked to specify how they are going to perform the action and think about any cues they might use to remind themselves of the task. They will then be prompted to construct if-then plans to account for potential barriers. Participants will be asked to choose a category of actions (e.g. actions surrounding physical activity) at the beginning of the week and will be offered action plans within this category for the whole week. By the end of the week, they will thus be able to make conclusions about the effectiveness of this category of actions. On a weekly basis, participants will receive an email with feedback on the weeks progress. The email will also include a link to another self-regulation prompt using the online software Qualtrics, in which participants will be asked to reflect on their behaviour throughout the week and try to explain observed weight changes. The questionnaire will also ask participants to reflect on the effectiveness of the week’s strategy (i.e., category of actions), and whether they would like to continue using this category of actions in the future. At the start of the next week, participants will be encouraged to keep performing effective weight loss actions while trying out a new set of actions. After the eight weeks of the intervention are finished, participants will be sent a final online questionnaire via email (Qualtrics), which asks them about their opinion regarding the usefulness of the intervention components. Participants in the control group will be asked to weigh themselves daily for eight weeks. Participants will receive special body scales, which are equipped with a SIM card and automatically transfer their weight measurements to a secure research server via the 3G/4G network. This data is used to assess adherence to daily weighing in the control group. |
| Intervention type | Behavioural |
| Primary outcome measure | The early effectiveness of a self-regulation intervention compared to unsupported daily weighing for weight loss, measured through change in body weight between baseline and 2 months follow-up by condition |
| Secondary outcome measures | 1. The usage and effectiveness of the self-regulation intervention components, measured across the two months of the study through: 1.1. Adherence to intervention components, assessed through weight records and daily action-planning/weekly evaluation questionnaires 1.2. Action plan use and evaluation, based on information from daily and weekly questionnaires, and 2 months follow-up interviews 2. Participant experiences of the self-regulation intervention for weight loss, measured at 2 months follow-up through: 2.1. Liking and perceived effectiveness of intervention features based on 2 months follow-up interviews 2.2. Barriers and unmet needs for successful weight loss, assessed in 2 months follow-up interviews |
| Overall study start date | 15/03/2018 |
| Overall study end date | 31/10/2019 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | Both |
| Target number of participants | 100 |
| Total final enrolment | 100 |
| Participant inclusion criteria | 1. Participant is willing and able to give informed consent for participation in the study 2. Aged 18 years or above 3. Body Mass Index ≥30 kg/m2 4. Ownership of an Apple or Android smartphone |
| Participant exclusion criteria | 1. Unable to understand English 2. Measures body weight more than once a week 3. Currently or recently (within 3 months of study entry) attended a weight management programme or currently participating in another weight loss study 4. Lost more than 5% of current body weight in the last six months 5. Had bariatric surgery, or scheduled for bariatric surgery 6. Pregnant, or planning to become pregnant during the course of the study 7. Have an electronic medical implant, such as a pacemaker 8. Have ever had or been diagnosed with an eating disorder 9. Patients that the GP judges not able to meet the demands of either treatment programme or measurement schedule. This may include severe medical problems not listed above or severe psychiatric problems including substance misuse that make following the treatment programme or adhering to the protocol unlikely |
| Recruitment start date | 14/01/2019 |
| Recruitment end date | 22/08/2019 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centre
Radcliffe Observatory Quarter
Woodstock Road
Oxford
OX2 6GG
United Kingdom
Sponsor information
University/education
Joint Research Office
1st Floor, Boundary Brook House
Churchill Drive
Headington
Oxford
OX3 7LQ
England
United Kingdom
| Website | https://researchsupport.admin.ox.ac.uk/ctrg |
|---|---|
"ROR" |
https://ror.org/052gg0110 |
Funders
Funder type
Government
No information available
Results and Publications
| Intention to publish date | 31/10/2020 |
|---|---|
| Individual participant data (IPD) Intention to share | No |
| IPD sharing plan summary | Not expected to be made available |
| Publication and dissemination plan | The trial results will be published and all who meet the criteria for authorship will be listed as authors. Results will also be presented at lay and scientific forums. There are no plans to publish any other materials from the study. |
| IPD sharing plan | The datasets generated during and/or analysed during the current study are not expected to be made available as they may contain information that could compromise research participant privacy. Quantified data from the trial, such as weight measurements, may be published as supplemental material to the main outcome paper. All data will be held securely on a departmental drive and will only be accessible by members of the trial management group. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Statistical Analysis Plan | version V1.0 | 21/10/2019 | 28/10/2019 | No | No |
| Protocol article | protocol | 08/12/2019 | 22/10/2020 | Yes | No |
| Results article | results | 01/09/2020 | 03/11/2020 | Yes | No |
| HRA research summary | 28/06/2023 | No | No |
Additional files
- ISRCTN14148239_V1.0_21Oct19.pdf
- Uploaded 28/10/2019
Editorial Notes
03/11/2020: Publication reference added.
22/10/2020: Publication reference added.
28/10/2019: Uploaded statistical analysis plan.
09/09/2019: Total final enrolment number added.
08/08/2019: The recruitment end date was changed from 31/07/2019 to 22/08/2019.
08/05/2019: The following changes were made to the trial record:
1. The recruitment end date was changed from 30/04/2019 to 31/07/2019.
2. The overall end date was changed from 30/06/2019 to 31/10/2019.
3. The intention to publish date was changed from 30/06/2020 to 31/10/2020.
