Open access Protocol Clinical efficacy of a virtual reality tool for the treatment of obesity: study protocol of a randomised controlled trial Dimitra Anastasiadou ‍ ‍,1,2 Mel Slater,3,4 Bernhard Spanlang,3 Desiderio Cano Porras,5 Marta Comas,6 Andreea Ciudin,6 Gemma Parramon Puig,7,8 Julia Vázquez-­De Sebastián,1,9 Jose Antonio Ramos-­Quiroga,7,8 Pilar Lusilla-­Palacios7,8 To cite: Anastasiadou D, ABSTRACT Slater M, Spanlang B, Introduction Previous research has shown that it is STRENGTHS AND LIMITATIONS OF THIS STUDY et al. Clinical efficacy of a feasible to integrate motivational interviewing techniques ⇒ The present study is designed as a randomised virtual reality tool for the controlled trial and uses a rigorous methodology with behavioural and psychological interventions for treatment of obesity: study containing three (treatment conditions) X 4 (assess- the treatment of obesity. Moreover, these combined protocol of a randomised interventions have the potential to improve health-­related ments) factors. controlled trial. BMJ Open outcomes of people living with obesity (PLWO) and to ⇒ Intention-­to-­treat analyses will be performed using 2022;12:e060822. doi:10.1136/ bmjopen-2022-060822 afford maintenance of behavioural changes over time. hierarchical linear models to examine the longitu- In addition, the use of virtual reality (VR) embodiment dinal changes of participants according to their as- ► Prepublication history and signed treatment group. techniques in the treatment of eating disorders and obesity additional supplemental material ⇒ The sample size was calculated taking into account has promising preliminary effectiveness. The objective for this paper are available of this study is to assess the clinical efficacy of a VR the low treatment adherence of this population and online. To view these files, please visit the journal online intervention that uses embodiment and body-­swapping consequently, the high dropout rates; to deal ade- (http://dx.doi.org/10.1136/​ techniques and has been specifically developed to cover quately with this limitation, an extra 20% of patients bmjopen-2022-060822). the needs of PLWO. will be recruited. Methods and analysis A randomised control trial will be ⇒ This is the first time that people with obesity receive Received 05 January 2022 carried out with an estimated sample of 96 participants an intensive training on motivational interview- Accepted 26 May 2022 with body mass index (BMI)>30. The whole duration of ing skills to conduct their own motivational self-­ the trial will be 12 months. Participants will be recruited conversation using the ConVRself platform. By doing from the external consultations of the Vall d'Hebron so, we hope to find promising long-­term effects in University Hospital and be randomly assigned to three the acquisition and maintenance of healthy lifestyle groups. The experimental group 1 will engage in a virtual habits in this population. self-­conversation using the ConVRself platform, the experimental group 2 will participate in a ‘pre-­established discourse’ provided by the virtual counsellor, who will give psychoeducation advice, and the control group will nearly tripled since 1975, with 11% of adult continue with treatment as usual. Readiness to change, men and 15% of adult women being obese.1 BMI, eating habits and physical activity, psychological Developing effective treatment approaches well-­being, body image satisfaction, quality of life in for obesity is essential to reduce comorbidi- relation to body image, and weight bias internalisation will ties and associated costs, and has been identi- be assessed at baseline, post intervention, 1-­week and fied as a research and public health priority.2 3 4-­week follow-­up. Finally, variables related to adherence Current guidelines for the treatment of and satisfaction with the VR tool will be evaluated for the obesity4–6 recommend psychological and experimental groups. behavioural weight management inter- Ethics and dissemination This study was approved by ventions to increase physical activity (or to © Author(s) (or their the Research Projects Committee of the Vall d’Hebron decrease inactivity), improve eating behaviour employer(s)) 2022. Re-­use University Hospital. Findings will be disseminated through peer-­reviewed journals, reports to the funding body, and diet quality and reduce energy intake as permitted under CC BY-­NC. No commercial re-­use. See rights conferences and other events for the scientific and clinical well as to promote treatment adherence and and permissions. Published by community, and the general public. self-­efficacy. These typically include dietary BMJ. Trial registration number NCT05094557. and physical activity-­related psychoeducation, For numbered affiliations see prescriptions and behavioural skills, such as end of article. self-­monitoring, stimulus control, goal setting Correspondence to INTRODUCTION and problem-­ solving, in combination with Dr Dimitra Anastasiadou; In recent decades, the prevalence of obesity cognitive skills. However, these treatments ​dimitra.​anastasiadou@​vhir.​org has markedly increased worldwide and has often fail, and one of the main reasons for Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 1 Open access this is the lack of motivation to change among patients or more) avatars while being immersed in a VR environ- the failure to maintain behavioural change strategies after ment, still maintaining embodiment.22–24 Thus, by using treatment.7 In fact, most patients experience significant ConVRself, patients can engage in a self-­ conversation weight regain within a year of completing treatment and in which they try solving their problem using their own nearly half of participants return to their original weight words by switching between an avatar of themselves and within 5 years.8 9 A recent study shows that people living an avatar of a counsellor. During the self-­conversation in with obesity (PLWO) who demonstrated personal motiva- VR, patients experience two different embodied perspec- tion to lose weight were more likely to report successful tives of themselves and their problem, a first-­person and weight loss compared with unmotivated people.10 a second-­person perspective. The self-­conversation will Motivational interviewing (MI) is a person-­ centred take place by exposing patients to four VR experiments approach to counselling in which individuals are encour- with ConVRself: ‘embodied discussion about problem aged to identify their own goals (and the discrepancies and solutions’, ‘overcoming (self-) stigmatisation’, ‘illus- between those goals and their current condition), and to trating the possibility of autonomy’ and ‘summing-­up’. discover a way towards behavioural change with uncondi- The tool has shown preliminary effectiveness using the tional support by their therapist.11 This strategy follows a self-­ conversation technique with samples of university non-­judgmental style in which ambivalence to change is students in terms of greater mood improvement and accepted as normal. The goal is to help the individual, happiness, and greater perception of change and help for through a collaborative conversation with the therapist, the personal problem after the intervention.23 24 to strengthen motivation and commitment to change in The present study, framed within the SOCRATES the context of the own desired outcomes. project, aims to assess the efficacy of the ConVRself as Research shows that it is feasible to integrate MI tech- a therapeutic tool that promotes behavioural change niques with behavioural and psychological interventions among PLWO. For this, we will conduct an RCT with two for weight loss, including cognitive behavioural therapy experimental groups (experimental group 1 (EG1) and (CBT). Interventions combining both MI and CBT have EG2)) and a control group (CG). Each group will receive the potential to improve health-­related outcomes among its assigned intervention during a period of 10 weeks. PLWO, especially in the long term.12 A meta-­analysis of Participants in the EG1 will receive a combined interven- randomised controlled trials (RCT) using MI techniques tion that includes: for the treatment of overweight and obesity found an ► Intensive training on basic skills related to MI and enhanced effectiveness when using MI in combination CBT (one face-­to-­face visit and two follow-­up phone with a behavioural weight management programme.13 calls) In addition, the incorporation of new technologies ► Psychoeducational advice in video format among clinical treatments for obesity has increased ► Multidisciplinary treatment with practical recommen- steadily in the past few years and has taken on a special dations to achieve a gradual weight loss and engage relevance during the COVID-­19 crisis management.14 For with physical exercise (treatment as usual (TAU)) instance, eHealth interventions have shown promising ► Body-­ swapping VR intervention through ConVRself long-­term effects in the improvement of healthy lifestyle (four face-­to-­face visits). among PLWO.15 Furthermore, virtual reality (VR) has The EG2 will receive the following: been used in the treatment of eating disorders (EDs) and ► Psychoeducational advice in video format obesity and has been associated with a reduction in food ► TAU cravings, improvement in body image and enhancement ► VR intervention through ConVRself without body of emotion regulation skills.16–19 However, the studies swapping (four face-­to-­face visits). reporting VR-­based treatments are limited because they The CG will receive the following: essentially deliver the same CBT in a safe VR environment ► Psychoeducational advice in video format without addressing the deep causes of obesity, such as lack ► TAU. of motivation to change or self-­stigmatization, key aspects Detailed information regarding each intervention for having long-­term effects. should be found below, in the ‘Interventions’ section. The SOCRATES (Self Conversation in Virtual Reality In particular, we aim to examine whether self-­ Embodiment to Enhance Healthier Lifestyles Among conversation through embodied perspective taking (body Obese People) European project (https://socratesvr.​ swapping) in a VR environment together with the integra- eu) aims to use VR from a user-­ centred perspective tion of learnt skills on MI and CBT (EG1) might account focusing on the specific needs of PLWO. For this goal, for helping participants to overcome the obesity-­related the SOCRATES project will adapt ConVRself, an existing problems described below, as the first study hypothesis, platform that adopts MI and CBT principles and uses compared with being embodied in their own virtual embodiment and body-­swapping techniques to promote representation without using the body-­swapping feature a self-­conversation in VR. While VR embodiment provides (EG2) or compared with standard multidisciplinary treat- a body ownership illusion enabling patients to experi- ment for obesity at their hospital (CG). ence the perceptual illusion that a virtual body is their The implementation of the body-­swapping VR inter- own,20 21 body swapping allows switching between two (or vention proposed for the EG1 is expected to result in a 2 Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 Open access significant improvement in the primary and secondary ► Receiving ambulatory treatment at the Vall d’Hebron outcomes (see below) compared with the treatments University Hospital proposed for the EG2 and CG. More specifically, we ► No concurrent involvement in other treatment related expect that: to the obesity condition ► The combined intervention of the EG1 would lead ► Minimal digital skills. This refers to being able to to significantly greater improvements (differences use a digital device (smartphone, tablet, computer) between baseline and post intervention, which should to make phone calls and video conversations via the also be maintained at 1-­week and 4-­week follow-­up) internet, send or receive emails, and search for infor- in the primary outcome, that is to say, readiness to mation about products and (health) service engage in healthier lifestyle, and in the secondary ► Oral and written understanding of the Spanish outcomes (ie, body mass index (BMI), psychological language functioning in terms of symptoms of depression and ► Agreement to sign the informed consent in order to anxiety, eating behaviours, body satisfaction, weight participate. bias interiorisation, and eating and exercise habits), in comparison to the EG2 and CG interventions. Exclusion criteria ► Participants from the EG1 would report greater levels ► Presence of an ED at least during 2 years of perceived acceptability and usability of the plat- ► Non-­ stabilised severe mental disorder that could form, as well as higher subjective rating of the illusion interfere with the successful implementation of the of body ownership of the virtual avatar(s), compared research protocol (ie, psychosis, depression with with EG2. suicidal risk, alcohol or drug abuse, psychotic or manic symptoms) METHODS AND ANALYSIS ► Auditory or visual complications that may interfere Patient and public involvement with the correct performance of the virtual experi- Patients recruited for the RCT will not be directly involved ence, such as uncorrected decreased visual or hearing in the design of the platform. However, a previous usability capacity or other conditions that may affect correct study, which is not described in the present protocol, was perception (including eye diseases that are common conducted with patients with morbid obesity from the Vall among diabetic patients, such as diabetic retinopathy, d’Hebron University Hospital (Barcelona, Spain). These macular oedema, cataracts, and glaucoma) patients were exposed to one VR session using ConVR- ► Intellectual disability or any major illness seriously self and provided feedback about their experiences and affecting cognitive performance (ie, neurological uncovered needs during the virtual experiments. This disorders) feedback helped the team to develop an updated version ► Personal history of epilepsy. of ConVRself adapted to the specific needs of PLWO. Procedure and randomisation Design Healthcare professionals specialised in obesity from The study proposes a RCT with three parallel groups (EG1 the Vall d’Hebron University Hospital will recommend vs EG2 vs CG) with 1:1:1 allocation. The study design will patients potentially suitable to participate in the study. contain three (treatment conditions) X 4 (assessments) To identify potential candidates for the study, profes- factors. Assessment factors are baseline (T0), post inter- sionals will do a preliminary screening of the patients vention (T1), 1-­week (T2) and 4-­week follow-­up (T3). with obesity currently under care, according to the inclu- The design and planning of this study protocol follow the sion and exclusion criteria established for the present Standard Protocol Items: Recommendations for Inter- study. Individuals will be able to confirm their partici- ventional Trials 2013 statement (https://www.spirit-state- pation by notifying their interest. A representation of ment.org). women and men consistent with the actual gender distri- Sample bution of obesity in Spain25 will be pursued. In specific, The total sample that will be recruited for the RCT according to obesity prevalence data from the Spanish will be 96 patients with a BMI between 30 and 45 kg/ National Institute for Statistics from 2020, 52% of the m2 (see ‘Sample size calculation’ section). The partici- sample is expected to be male and 48% female. Then, pants will be recruited from the Obesity Unit of the Vall an appointment will be made with a clinical researcher d’Hebron University Hospital and will be patients with of the SOCRATES team at the Vall d’Hebron Research obesity receiving regular multidisciplinary treatment at Institute (VHIR). In this first appointment, participants the hospital (see ‘Treatment as usual’ description below) will be informed about the study, the data confidentiality, and willing to improve their obesity-­related condition and and the possibility to withdraw from the study whenever associated problems. they want without losing any other rights or benefits, and then will be asked to sign the informed consent. Straight Inclusion criteria after completing and signing these documents, the same ► Age between 18 and 65 years clinical researcher will conduct initial clinical interviews 2 2 ► BMI≥30 kg/m and ≤55 kg/m with the participants to confirm their eligibility to the Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 3 Open access the clinical researcher will ask the participants of the EG1 and EG2 if they want to receive an extra experimental session. If a participant does not want to receive an extra session, the experimental sessions will finalise for him/ her. If a participant wants an extra session, he/she will be exposed again to the final ‘summing-­up’ session (see ‘Interventions’ section below) only if he/she meets two or more of the following criteria: (1) scores on any of the readiness rulers below four points; (2) lack of under- standing of the virtual MI dialogue (only for the EG1); (3) spontaneous demand for the extra session. Lastly, the ‘4-­week follow-­up’ will be conducted and include the same self-­report questionnaires as the ones delivered at the ‘baseline assessment’. Right after finalising each of the four experimental sessions, the accompanying clinical researcher will assess if any adverse event occurred. For example, whether participants experience cyber sickness, dizziness, discom- Figure 1 Procedure and timeline of the study. ass., fort, nausea, or feel confused or disoriented during their assessment; CG, control group; EG, experimental group; practice with the system. The procedure will stop when TAU, treatment as usual; VR, virtual reality. the clinical researcher or the participant consider it necessary. Besides, if a significant worsening on the partic- study and evaluate possible comorbidities. At this time, ipant’s psychological well-­being is identified during the sociodemographic and clinical data of each patient will whole procedure, a face-­to-­face visit with the researcher of also be collected. Those who meet the eligibility criteria the SOCRATES team will be scheduled to assess whether will follow two procedures. First, they will be invited to or not he/she will have to discontinue participation in complete the ‘baseline assessment’ (self-­ report ques- the trial. tionnaires through paper or online surveys at home). Figure 1 presents the study’s procedure and timeline. It Second, they will have a photography session in which two is worth mentioning that recruitment started in January photographs front and side will be taken for each partic- 2022 and is expected to be completed by October 2022, ipant. This photography session before the beginning of while data collection will be completed by January 2023. the experiment will serve for all patients as a means of Figure 2 describes the procedure for the interventions observing and comparing their body shapes before and of EG1 and figure 3 describes the procedure for the after the intervention. For patients of the experimental intervention of EG2. Finally, table 1 provides a detailed groups, these photographs will be used by the team to description of the methodology with a definition of the prepare the participants’ avatars for the VR experience. study variables and their assessment tools for each one of After completing the baseline questionnaires, partic- the three groups. To optimise participants’ retention and ipants will be randomised to one of the three groups complete follow-­up, reminder emails will be sent to all (EG1, EG2 or CG). An independent researcher of the participants at T1, T2 and T3. SOCRATES team blind to the research questions and treatment conditions will carry out the randomisation Interventions through a list of randomly generated numbers using Intensive training on basic skills related to MI and CBT IBM SPSS V.24 software.26 Then, the clinical researcher Participants assigned to the EG1 will be invited to partic- carrying out the initial interviews will be responsible for ipate in the 3-­day intensive training on basic skills of communicating the assignment group to the participants, MI11 27 and CBT,28–30 which will be carried out by the clin- through a phone call, together with the specific identifi- ical researchers’ team from VHIR. This intensive training cation code for each one of them. Next, the experimental will consist of a 4-­hour face-­to-­face group session in day 1, sessions will be carried out, which will last for 6 weeks. It is and 2 individual 30 min telephone coaching sessions in worth mentioning that a clinical researcher of the VHIR day 2 and day 3. The objective of this training will be to team will always accompany the participants during the provide patients with specific skills that will enable them VR experiments and guide them on the correct use of the to conduct a productive self-­conversation in a VR setting. platform. This training is considered a unified intervention with the After the participants’ exposure to their assigned inter- “Body-­swapping VR intervention” (see below). Since EG2 ventions (see ‘Interventions’ section below), the ‘postin- participants will only have a passive role in their VR expe- tervention assessment’ will take place. One week later, the riences (not a self-­conversation with body swapping), they ‘1-­week follow-­up’ will be conducted, which will include will not be assigned to the intensive MI and CBT training. a brief interview with the clinical researcher and several During the day 1 training, participants will learn to self-­report questionnaires. In the same follow-­up session, better understand their own process of change, be more 4 Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 Open access Figure 3 Procedure of the experimental sessions for the experimental group 2. * See ‘Statistical analysis’ section about the inclusion of the number of sessions in the data analyses VR, virtual reality. compassionate and empathetic, and thus become better counsellors for themselves. The basic goal of this training is to prepare and instruct participants to organise their Figure 2 Procedure of the intensive training and self-­dialogue better so that they can persuade themselves experimental sessions for the experimental group 1. * See ‘Statistical analysis’ section about the inclusion of the to change, based on their own values and interests. The number of sessions in the data analyses. CBT, cognitive session will combine a PowerPoint presentation and behavioural therapy; MI, motivational interviewing; VR, virtual videos showing several role-­ playings among patient/ reality. counsellor dyads practicing the skills learnt. The session Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 5 6 Table 1 Study variables and assessment tools for each group Experimental group 1 and 2 Post Exp 4/ Baseline Post training Post Exp. 1 Post Exp. 2 Post Exp. 3 post Interv. 1-­week FU 4-­week FU Sociodemographic, clinical variables and body mass index Open access  1. Sociodemographic data X  2. Clinical data related to obesity X  3. Medical and psychological antecedents X  4. Body mass index X X X X  5. Cognitive reserve X Self-­report questionnaires for psychological well-­being  1. Readiness rulers X X X X X X X  2. Stages and processes of change questionnaires in X X X X weight management  3. Three Factor Eating Questionnaire X X X X  4. Body Shape Questionnaire X X X X  5. Body Image Quality of Life Inventory X X X X  6. Modified Weight Bias Internalization Scale X X X X  7. Hamilton Anxiety and Depression Scale X X X X  8. Lifestyle habits questionnaire X X X X Adherence and satisfaction  1. Suitability Evaluation Questionnaire X X X X  2a. Body ownership: proper avatar X X X X  2b. Body ownership: avatar of counsellor (only EG1) X X X X  3. Users’ experience (interview) X X X X Knowledge acquisition questionnaires  1. MI Knowledge Acquisition Questionnaire (only EG1) X  2. Cognitive change (only EG1) X Control group Post Exp. 4/ Baseline Post training Post Exp. 1 Post Exp. 2 Post Exp. 3 post Interv. 1-­week FU 4-­week FU Sociodemographic, clinical variables and body mass index  1. Sociodemographic data X  2. Clinical data related to obesity X  3. Medical and psychological antecedents X Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 Continued Table 1 Continued Control group Post Exp. 4/ Baseline Post training Post Exp. 1 Post Exp. 2 Post Exp. 3 post Interv. 1-­week FU 4-­week FU  4. Body mass index X X X X  5. Cognitive reserve X Self-­report questionnaires for psychological well-­being  1. Readiness rulers X X X X  2. Stages and processes of change questionnaires in X X X X weight management  3. Three Factor Eating Questionnaire X X X X  4. Body Shape Questionnaire X X X X  5. Body Image Quality of Life Inventory X X X X Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822  6. Modified Weight Bias Internalization Scale X X X X  7. Hamilton Anxiety and Depression Scale X X X X  8. Lifestyle habits questionnaire X X X X Adherence and satisfaction  1. Suitability Evaluation Questionnaire   2a. Body ownership: proper avatar   2b. Body ownership: avatar of counsellor  3. Users’ experience (interview) Knowledge acquisition questionnaires  1. MI Knowledge Acquisition Questionnaire  2. Immediate Cognitive Change CI, clinical interview; EG1, experimental group 1 ; Exp, Experiment; FU, follow-­up; Interv, Intervention; MI, motivational interviewing. Open access 7 Open access will also give participants the opportunity to practice such to the VR experience, patients will be able to choose skills and receive feedback. Training will be interactive among different gender-­ matched counsellor’s avatar with an open session for questions. options, including young normal weight, old normal The objective of the day 2 training is to help patients weight, young overweight and old overweight. Once the to identify and address obstacles to weight loss (dysfunc- experiment starts, the patient, embodied in his/her own tional thoughts, emotional and external triggers) and body, will start describing his/her positive lifestyle change create a personalised case formulation based on CBT he/she would like to make, in terms of eating healthier or principles. At the end of day 2 training, the ‘letter to the being more physically active. Then, he/she will be body future exercise’ will be sent as a homework to all partici- swapped to the counsellor’s body and try to respond to the pants (‘Imagine how you would like to be in 2027. Think problem just manifested by the patient, inspired by the of a realistic and good situation. From 2027, write a MI and CBT techniques learnt in the intensive training. letter to the person you are now in 2022 explaining how The crucial aspect here is that the patient, from the coun- you have achieved your goals, the things you have had sellor’s viewpoint, will see a representation of his/her real to change and how you have changed them’), together body when looking at the patient’s avatar speaking and with a first-­aid kit (in PDF format) summarising the most moving. The counsellor will also be able to give instruc- important contents of the training, suggesting questions tions to the patient’s avatar (ie, by pressing buttons on a to ask during the self-­dialogue and tips about how to panel in front, within the VR environment) to make the deal with difficult situations related to being with obesity. avatar of the person on the other side automatically stand Homework will be revised and commented with the clin- up, turn around and so on. ical researcher during the day 3 training. Knowledge acquisition based on the specific learning objectives will Experiment 2: overcoming self-stigmatisation be assessed at the end of day 3 training using self-­report In this second experiment, the patient will maintain a questionnaires. conversation with the same counsellor as the one chosen for the experiment 1. The patient, embodied in his/ Psychoeducational advice in video format her own body, will start describing his/her problem in Participants from the three groups will receive psycho- terms of subjective experiences of body size discrimina- educational advice in video format that will cover the tion due to the condition of living with obesity and how following obesity-­ related topics: (a) multicausality of different life would be if he/she considered a specific obesity; (b) multidimensional effects of obesity; (c) change in his/her life. Then, the participant will be body description of obesity-­related bias and its potential adverse swapped to the counsellor’s avatar and will respond to the outcomes; (d) evidence detailing effective treatments for problem posed by the participant using MI skills learnt obesity reminding that it is a complex, chronic condition during the training. While interacting with his/her own that requires lifelong management and efforts; (e) impor- self-­representation from the counsellor’s perspective, the tance of body respect and acceptance. This 30 min video patient’s avatar will slowly morph between different body will be sent to them via email after their first appointment shapes, including the real body size and a ‘better’ one. It is at the hospital (baseline assessment session). worth mentioning that throughout the whole experiment we will follow the ‘Healthy At Every Size’ approach,31 Treatment as usual and encourage the use of the term ‘best weight’ (ie, the TAU will consist of regular medical, nutritional and/or weight that a person can achieve and maintain while psychiatric follow-­ups with the obesity specialists of the Vall d’Hebron University Hospital and standard routine living a healthier and happier life). The objective of this tests. These visits aim to improve patients’ health status, session will be to reduce self-­weight bias and acknowledge provide them with practical recommendations to achieve that weight is not a behaviour, encouraging thus body a gradual weight loss and engage more with physical acceptance).The point here is to show that while the body exercise, and finally, prevent or treat possible clinical size may change, the underlying person does not change, conditions requiring weight improvement, such as type and that body size should not influence the real essence 2 diabetes. of that person. This experience will provide an implicit illustration of the fact that body weight and size are inde- Body-swapping VR intervention (EG1) pendent of the core personality traits and intrinsic values Participants of the EG1 will engage in a self-­conversation of a person. through embodied perspective taking (body swapping), according to which they will be embodied alternately in Experiment 3: illustrating the possibility of autonomy their own virtual representation and in their counsellor’s In this experiment, the patient embodied in his/her own virtual body by means of 4 experiments with ConVRself. body will interact with a future and healthier/happier version of himself/herself. Thereby, in this experiment, Experiment 1: embodied discussion about problem and solutions the patient will not be interacting with the counsellor’s In this experiment, patients will be embodied in their avatar as happened in experiments 1 and 2, but with a own (self-) avatar and will maintain a conversation with a future self-­ avatar in 5-­ year time, a self-­ avatar who has counsellor’s avatar of their choice. Before being exposed achieved his/her ‘best weight’. Therefore, the patient will 8 Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 Open access first observe his/her future self in front of him/her and Experiment 4: summing up will ask how that healthy condition was achieved and what In this last experiment, the patient, embodied in his/her steps were taken in order to achieve that healthy body own body, will participate in a ‘pre-­established discourse’ weight. Then, the patient, from the embodied perspec- provided by the chosen counsellor who will make a summary tive of his/her future self, will come up with his/her own of the main concepts explained during the previous ideas about how he/she has achieved those outcomes. experiments. Responses will be also encouraged by the MI and CBT skills acquired during the intensive training, in particular Variables and measurements the ‘letter to the future’ exercise. The primary outcome will be readiness to change habits and secondary outcomes will include BMI, eating habits, Experiment 4: summing up general psychological functioning, body satisfaction, weight In this last experiment the participant will be embodied bias interiorisation, and eating and exercise habits. Besides, in his/her own body and will maintain a conversation with sociodemographic and clinical variables as well as variables the same counsellor as the one chosen for the experiment related to the adoption of the VR tool in terms of perceived 1. The patient will start describing what has been learnt, usability, user’s acceptability, satisfaction and body ownership experienced and changed in his/her lifestyle during the (for the experimental groups) will also evaluated. Finally, we previous experiments. Then, the participant will be body will measure knowledge acquisition related to the specific swapped to the counsellor’s avatar who will respond to contents of the training during the intensive training of the the participants’ achievements using MI skills. In addi- EG1. tion, patients will be invited to use the self-­conversation to address how to adapt the lessons learnt to achieve a Sociodemographic and clinical variables healthier lifestyle and sustain their ‘best weight’ after the Information about participants’ age, gender, level of educa- treatment is over. When the self-­conversation comes to tion, marital and employment status as well as clinical infor- an end, the counsellor will say goodbye and thank the mation (ie, presence of physical or mental health problems, patient for his/her participation. comorbidities, medication, illness duration, family history of physical or mental health problems) will be collected VR intervention without body swapping (EG2) through a semistructured interview by clinical researchers Experiment 1: embodied discussion about problem and solutions of the VHIR. The fulfilment of the inclusion criteria will As in EG1, participants will be embodied in a self-­avatar. be assessed through the above-­mentioned interview and in In addition, for the counsellor’s avatar, participants will case of doubt, patients’ electronic health records (EHR) be able to choose among different avatar options that will will be consulted. Finally, the weight and height of each be gender matched (young normal weight, old normal participant will be measured at the Vall d’Hebron settings. weight, young overweight and old overweight). Once the Weight measurements will always be taken by trained staff VR experiment starts, the patient, embodied in his/her of the SOCRATES team at the same time of the day and own body, will participate in a ‘pre-­established discourse’ using a digital scale. The patient will be advised to wear light provided by the chosen counsellor, who will ask about the clothing, go barefoot, and adopt a straight body position perceived barriers for engagement with a healthier life- while being weighed. Height will be obtained by consulting style and will give practical recommendations about how the patients’ EHR and taking its most recent measurement. to achieve a healthier and happier life, in terms of healthy Finally, BMI will be calculated as weight in kilograms divided eating and physical activity. by height in square metres W (kg)/H (m2). Experiment 2: overcoming self-stigmatisation Readiness to change For experiment 2, the patient, embodied in his/her own Readiness Rulers (RR) body, will participate in a ‘pre-­ established discourse’ RR11 are Visual Analogue Scales ranging from 1 to 10 provided by the chosen counsellor who will ask about that assess ‘importance’, ‘confidence’ and ‘readiness’ to subjective experiences of size discrimination due to the change. For the present study, these three variables will condition of living with obesity in daily life and will give be measured in terms of (a) achieving a healthy weight practical recommendations about how to achieve body and (b) exercising more, while the ‘readiness’ to change respect and body acceptance. scale will be used as critical response primary variable. The advantage of these scales is that they are brief, easy Experiment 3: illustrating the possibility of autonomy to use, and possess good psychometric properties in For experiment 3, the patient, embodied in his/her own addiction studies.32 In addition, through these scales body, will continue participating in a ‘pre-­ established behavioural change is measured as a continuous process discourse’ provided by the counsellor of his/her choice. rather than a categorical construct that positions each This counsellor will ask about what could happen in the individual in a specific stage of change according to the future if the patient continues in his/her current condi- transtheoretical model.33 Lower numbers represent ‘not tion and also talk about the physical and psychological willing’ to change, ‘not confident’ and ‘not prepared’ to consequences of obesity. change, scores of 4–6 represent ambivalence in terms of Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 9 Open access ‘somewhat willing/confident/prepared to change’, and The questionnaire consists of 18 items using a 4-­point the higher numbers represent ‘very willing/confident/ response scale, which ranges from 1 (definitely true) to prepared to change’ or ongoing attempts of changing. 4 (definitely false), and item scores are summated into It is worth highlighting that high correlations among the the three different subscales: CR, UE and EE. Previous three rulers were found in a previous study with outpa- studies reported adequate psychometric properties of tients with alcohol abuse disorder.34 the instrument37 while the Spanish version38 showed ► The importance ruler: It gauges how important good internal consistency, ranging from 0.75 to 0.87 in a change is to a person at the present time, on a scale sample of young healthy adults. ranging from 1 (not at all) to 10 (completely). For example, ‘on a scale from 1 to 10, with 10 being very Lifestyle Habits Questionnaire important, how important is for you to achieve a This self-­report questionnaire39 has been developed and healthy weight?’. validated in Spain for the assessment and quantification ► The confidence ruler: It reflects how confident a person of lifestyle habits related to overweight and obesity. It is in committing to change at the present time, on a scale consists of 22 items, each one of which is rated using a from 1 to 10. For example, ‘on a scale from 1 to 10, with 5-­point Likert scale ranging from 1 (never) to 5 (always), 10 being completely confident, how confident are you in with higher scores indicating better lifestyle habits. The your ability to achieve a healthy weight?’. questionnaire assesses five dimensions related to lifestyle ► Readiness to change ruler: The scale evaluates how habits: diet caloric intake, eating in search of psycho- much prepared to change a person is, in terms of logical well-­being, physical activity, healthy eating, and specific actions that reflect commitment, on a scale alcohol intake. from 1 to 10. For example, ‘on a scale from 1 to 10, Other psychological variables with 10 being completely ready to take action, how Hamilton Anxiety and Depression Scale (HADS) ready are you to achieve a healthy weight?’. The questionnaire40 consists of 14 items, 7 for anxiety Stages and processes of change questionnaires in weight and 7 for depression, and is used to detect the presence management (S-Weight and P-Weight) and severity of anxiety and depression among people with As a complementary readiness to change measure, the physical illnesses. The HADS is scored on a 4-­point Likert Spanish version of the Stages of Change in Overweight and scale ranging from 0 to 3, with the total score ranging Obese People (S-­Weight) and the Processes of Change in from 0 to 42. Higher scores indicate a greater level of Overweight and Obese People (P-­Weight)35 will be used. The distress. Its Spanish validation among outpatients with S-­Weight consists of five mutually exclusive items that allow physical problems and healthy controls41 demonstrated allocating participants to one of the five stages of change good psychometric properties with a Cronbach’s α of 0.86 according to the transtheoretical model of change for weight for each subscale. management: precontemplation, contemplation, prepara- Body Shape Questionnaire (BSQ-10) tion, action and maintenance. The P-­Weight is composed The BSQ is a 10-­item self-­report instrument, derived from of 34 items for assessing four processes of change in weight the original 34-­item version developed by Cooper et al,42 management: (1) emotional re-­evaluation (13 items), (2) which assesses concerns about body shape expressed by weight management actions (seven items), (3) environ- clinical and non-­clinical samples. It is based on a 6-­point mental restructuring (five items), and (4) weight conse- Likert scale questions (never, rarely, sometimes, often, quences evaluation (nine items). Responses are on a 5-­point very often and always) with higher scores indicating Likert scale ranging from 1 (strongly disagree) to 5 (strongly higher body dissatisfaction. The original 34-­version has agree), with none of the items being reverse scored. Total demonstrated adequate psychometric properties among scores for each process of change are obtained by summing patients with ED42 and patients with obesity.43 Its short the individual items, in which lower scores reflect no use of a 10-­item version has also been validated among a Spanish-­ given process of change and higher scores reflect the full use speaking sample of patients with EDs and demonstrated of that process. To make scores from the different subscales metric invariance and more consistency compared with comparable, these scores are transformed on a scale ranging other short versions.44 from 0 to 100. The questionnaire showed adequate internal consistency (Cronbach α ranging from 0.78 to 0.96) and Body Image Quality of Life Inventory (BIQLI-SP) item-­total correlations in its Spanish validation,35 and it is a The BIQLI45 is a 19-­item instrument designed to quantify questionnaire highly recommended for the assessment of the impact of one’s body image experiences on several readiness to change for weight management and control.36 relevant facets of his/her psychosocial functioning and well-­being in everyday life. Participants rate the impact of Eating habits their own body image on 19 domains or contexts in which Three Factor Eating Questionnaire-R18 (TFEQ-R18) body image has been found to be consequential, including The questionnaire37 assesses three different aspects of day-­to-­day emotions, self-­esteem, sexuality and social rela- eating behaviour: (a) cognitive restraint (CR), (b) uncon- tionships, among others. The instrument uses a 7-­point trolled eating (UE), and (c) emotional eating (EE). bipolar scale ranging from −3 (very negative effect), to 0 10 Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 Open access (no impact) and to +3 (very positive impact). The BIQLI SEQ ranges from 13 (poor suitability) to 65 (excellent showed high internal consistency (Cronbach’s α=0.95) suitability). Items Q7, Q8, Q9, Q10, Q12 and Q13 are and good test–retest reliability of 0.79. The Spanish vali- reversed. Finally, given that the questionnaire is composed dation of the instrument46 showed adequate psychometric of different dimensions, it has not been possible to eval- properties among a sample of healthy Spanish students. uate its internal consistency. For the specific purposes of the present study, the word ‘rehabilitation’ of Q11 will be Modified Weight Bias Internalization Scale (WBIS-M) replaced by ‘obesity treatment’. The WBIS-­M47 is a self-­ report 11-­ item unidimensional scale that is considered one of the most frequently used Body ownership instruments for assessing internalised weight stigma At the end of each VR experiment, participants will do across different body weight categories, in both clinical a subjective rating of the illusion of body ownership and research settings. Each answer is rated using a 7-­point through a 7-­point Likert scale, where −3 means ‘strongly scale, ranging from 1 (strongly disagree) to 7 (strongly disagree’ and +3 ‘strongly agree’. The questions that will agree) with higher scores indicating higher internalised be asked were taken from a previous study evaluating weight bias. Items 1 and 9 are reverse scored. The orig- ConVRself24 and are the following: ‘Even though the inal WBIS-­M48 demonstrated high internal consistency body I see might not physically look like me, I feel that with a Cronbach’s alpha of 0.94, while the Spanish valida- the virtual body I see when I look down towards myself is tion showed excellent internal consistency and test–retest my body’ (body ownership-­look down); ‘Even though the reliability.47 body I see might not physically look like me, I feel that the virtual body I see reflected in the mirror is my body’ Cognitive Reserve Questionnaire (CRQ) (body ownership-­mirror); ‘I feel that the movements of The CRQ49 is a self-­report questionnaire developed and the virtual body are caused by my own movements’ (body validated in Spanish population, which evaluates the ownership-­movements); ‘The body I see in the virtual degree of cognitive reserve in healthy controls and in world physically looks like me’ (self-­recognition). The patients with early signs of Alzheimer’s disease. The CRQ same questions will be asked for both the patient’s self-­ is composed of eight items that assess aspects generally avatar and the counsellor’s avatar. related to cognitive reserve, such as own and parental educational status, occupational status, the completion Users’ experience of training courses, musical training, and mastery of A brief interview will be carried out after each experi- languages. In addition, the approximate frequency with ment to assess participants’ satisfaction with the VR expe- which cognitively stimulating activities have been carried rience and acceptability of the ConVRself tool, including out throughout life, such as reading and the practice questions related to their experience using the self-­ of intellectual games (ie, crossword puzzles and chess) conversation technique, in a VR context, to cope with are assessed. The CRQ score ranges from 0 to 25 and is their condition. divided into quartiles. In this way, a score equal to or less than 6 points (≤Q1) would show a low cognitive reserve, Knowledge acquisition during general training sessions between 7 and 9 points (Q1–Q2) would correspond to MI Knowledge Acquisition Questionnaire a low-­medium cognitive reserve, while scores between The questionnaire was used in the study of Rubak et al51 10 and 14 (Q2–Q3) would show medium-­high cognitive to evaluate general practitioners’ use of MI after having reserve. Finally, scores ≥15 points would be classified as received a training course in MI. For the specific purposes high cognitive reserve (Q4). of the present study, only the first four questions of the questionnaire will be used to assess knowledge acquisition Adherence and satisfaction of VR experiments of participants from the EG1. The questions reflect the Suitability Evaluation Questionnaire (SEQ) counselling style adopted by the participant in specific The SEQ50 is a 14-­item questionnaire designed to measure patient cases related to using either MI or ‘traditional satisfaction, acceptance, and security of use in VR systems advice giving’ (doctor-­centred approach). After reversing and it was specifically designed for rehabilitation systems individual item scores, the total score is calculated and using VR. Thirteen questions of the SEQ are based on divided by the number of items, thereby generating a a 5-­point Likert scale plus a last open-­ended question mean response for each question. offering participants the possibility to add comments, if necessary. According to the SEQ structure, the first Immediate Cognitive Change (CC-Immediate Scale) seven questions measure enjoyment, sense of being in the The CC-­ Immediate Scale52 is a 7-­ item questionnaire system, feeling of success and control, realism, easy-­to-­ based on a 7-­Likert scale that reflects patient’s experience understand instructions, and general discomfort. Then, of cognitive change and use of cognitive skills after the four questions measure dizziness or nausea symptoms, training sessions. The measure asks the patient to focus eye discomfort, disorientation or confusion symptoms. on the training session they just concluded and indicate The last two questions are focused on the difficulty in the extent to which he or she agrees with the items of the engagement with the system. The global score of the scale, where lower scores indicate less agreement. Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 11 Open access The instrument will be translated into Spanish by the In the EG1, a virtual counsellor previously chosen researchers of the SOCRATES team. by the participant appears in front of the participant (experiments 1 and 4). The virtual counsellor can be Technical features of the VR experiments also an altered representation of the participant’s own The VR system comprises the VR hardware, a tablet or appearance (experiment 2), or an older and healthier smartphone, and the VR software. As VR hardware, we one (experiment 3). Once in the VR environment, are going to use the Oculus Quest 2, a standalone headset pre-­recorded audio instructions ask the participant to that consists of the Head-­Mounted Display (HMD) that is describe a personal problem to the counsellor in front worn on the participant’s head and hand controllers. The of him/her. To make the self-­ conversation possible, HMD has a vision-­based inside-­out tracking system that while the participant describes this problem, the HMD’s enables it to track in real time the participant’s head posi- microphone is concomitantly recording the participant’s tion and orientation in 3D space. In addition, it can track voice and the system is tracking the participant’s move- the participant’s left and right hand position and orien- ments and storing them on the HMD memory. While the tation through the hand controllers, which are wirelessly participant is explaining his/her problem, the avatar of connected to the HMD via Bluetooth. The HMD has a the virtual counsellor in front may perform simple pre-­ powerful built-­ in processor that allows processing the recorded actions such as nodding, clearing the throat, incoming tracking and audio data and generates images etc. Then, the participant presses a virtual button on the for the left and the right eye (stereoscopic vision) and table in front that transforms the participant’s perspec- spatialised audio to the participant’s ears. In addition, tive to that of the virtual counsellor, which the participant the ConVRSelf system, which is built with the Unity3D then embodies (ie, body swapping). The participant’s games engine, animates and displays 3D scenarios and upper body movements are now mapped to his/her new virtual human representations. In addition to delivering body (ie, the virtual counsellor) and the participant thus real-­time images and audio, it can also cast the images can see new mirror reflections from this new embodiment perspective. At this point, the participant is able to see from inside VR via WiFi to a smartphone or tablet. If the his/her look alike avatar in front and can hear herself/ HMD delivers audio without additional headphones, the himself describing the problem (the one the participant audio is also audible by people nearby. That is why we described before). When the description of the problem will instruct the participant to wear headphones so that finishes, the participant embodied as the counsellor can the HMD sound will not overlap with other audio sources give advice to his/her original avatar. Once completed, (instructions, explanations, advice) from the experience. the participant as a counsellor can press a button on the To minimise potential COVID-­19-­related risks during virtual table and will then be transformed back to his/ the VR experiments, the research team will follow a safety her look alike avatar. From this virtual self-­representation, protocol including the mandatory use of the mask, the the participant can now listen to the advice he/she gave disinfection of the hands with hydroalcoholic gel and the as a virtual counsellor. Applied audio filters change the cleaning of the Oculus Quest 2 device with the CleanBox participant’s original voice to that of the counsellor. The (https://cleanboxtech.com/) CX1 disinfection system. participant can then respond and switch perspectives The following subsections describe the ConVRself soft- to give advice and to respond as often as he/she likes. ware and how look alike avatars (‘self-­avatars’) will be In the EG2, there will be no body swapping. Instead the created. counsellor’s avatar will give pre-­recorded advice after the participant has described his/her problem. Two addi- Software ConVRself tional movie files show in more detail how the first experi- The ConVRSelf software has three main stages: calibra- ment ‘embodied discussion about problem and solutions’ tion, tutorial and the experience. The calibration stage works for EG1 and EG2 (see online supplemental video 1 captures tracking data from the participant in an upright and online supplemental video 2). seated position while participants wear the HMD and hold the VR controllers in their hands. Collected data will allow Creating look alike avatars computing an internal human representation to drive the To create the look alike avatars, the system needs as embodied avatar’s movements for the tutorial and expe- input photos of the participant’s face, front and side view rience stage. The tutorial stage has more detailed audio photos of the participant’s whole body, and body weight instructions for the participant and prepares the partici- and height information. In a semiautomatic process, the pant to practice the actual experience. system deforms a template body mesh to match the weight In the tutorial and experience stages, the participant and height information, and front and side photos. Face first embodies a seated look alike avatar. The tracking of and hair will be inferred from the face photo and mapped the participant’s upper body movements is mapped to onto the 3D human model. Body shape will be adapted his/her avatar by using inverse kinematics techniques. for altered representations of the participant (such as A virtual mirror which reflects the scene and the partici- morphed body sizes or future healthier/happier self in pant’s virtual body is positioned to the left of the partici- experiments 2 and 3, respectively). We insert a skeleton pant (ie, inside the VR environment). and blend shapes to the template mesh in order to be 12 Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 Open access able to move the body, and for mouth and facial expres- demographic and clinical measures assessed at baseline. sions. The avatar data resulting from the process will then Then, intention-­to-­treat analyses will be performed using be loaded onto the VR device’s storage system from which hierarchical linear models (HLMs) to test the effect of the ConVRSelf system will load it. the three groups (EG1, EG2, CG) on readiness to change (RR scores on ‘preparation’ to eat healthier and exer- Sample size calculation cise more), BMI, eating behaviours (TFEQ-­ R18), life- The a priori sample size calculation was based on results style habits (lifestyle habits questionnaire), psychological from a previous study with individuals with an ED, which functioning (HADS), body satisfaction (BSQ-­10), quality implemented a 2-­week self-­compassionate letter-­writing of life related to body image (BIQLI-­SP) and weight bias intervention using the readiness to change ruler.53 A internalisation (WBIS-­M) over time (T0–T3), while effect medium between-­group effect size (Cohen’ s f=0.28) is sizes (Hedges’ g) will be reported. expected. The calculation was conducted using the soft- For the two experimental groups, the effect of treatment ware programme G*POWER. The primary analysis will condition (EG1 and EG2) on adherence, satisfaction concern the hypothesis that the average level of readiness with the virtual experiences (SEQ) and body ownership to change (‘preparation’ to eat healthier and to exercise (body ownership questionnaire) over time (post experi- more domains) at post intervention in the EG1, based ment 1–4), will be assessed using also HLM, while exam- on the RR score, will be higher compared with the EG2 ining the influence of age, gender, cognitive reserve and and the CG. Assuming an alpha of 0.05 and a power of number of experimental sessions in the results since they 0.80 (β−1) in a two-­way repeated measure analysis of vari- may condition performance in the virtual experiments. ance, a minimum of 27 participants would be required per study arm (three treatment conditions × four assess- ment factors). Allowing for a dropout rate of 20% of study DISCUSSION participants from baseline, taking the average score of In this article, we describe the protocol of the clinical similar previous studies evaluating VR interventions,17–19 validation study proposed for the SOCRATES European a total of 96 participants need to be recruited. project, in which we will assess the clinical efficacy of an embodiment body-­ swapping virtual intervention with Data management ConVRself, through an RCT. All data in paper form related to the trial, including The study will provide an important advance in the the clinical researchers’ paper notes, self-­ report ques- psychological treatments of obesity, first, by enhancing tionnaires and informed consent forms, will be securely the effectiveness of those treatments integrating embodi- stored in a key-­protected cupboard in the principal inves- ment and body-­swapping techniques in a VR context, and tigator’s office at VHIR. Regarding online data, these will second, by addressing the root causes of obesity following be saved on an encrypted online database (REDCap) the MI theoretical framework11 and the healthy at every of the VHIR’s password-­protected servers. Only autho- size paradigm.31 This is the first time that PLWO are rised researchers directly involved in the study will have properly trained on MI skills to conduct their own moti- access to this data. All data will be stored for a minimum vational self-­conversation using the ConVRself platform. of 5 years and be available on request from the corre- By doing so, we hope to find promising long-­term effects sponding author. All patients’ data will be processed in in the acquisition and maintenance of healthy lifestyle compliance with the Data Protection Impact Assessment habits in this population, in a sustainable way. (DPIA) document, which has been developed by the Regarding the limitations of the study, the design of clinical researchers of the VHIR team, in collaboration the study brings along some methodological difficulties, with the Legal and the Informatics departments of the especially the risk of a high dropout rate over time, also Vall d’Hebron hospital. The DPIA document will be regu- considering the clinical profile of this population that larly updated to stay on track with the project and inform usually shows low treatment adherence. To address this about any eventual changes. challenge, we include an extra 20% of patients in the trial After obtaining the signed informed consent from to ensure that the statistical power will be maintained participants, a unique alphanumeric code will be allocated despite patient attrition. to each one of them so that analyses can be conducted The age of the participants and their respective digital anonymously. The database that links participants to their literacy may condition acceptability of this novel treat- codes will be securely stored on a password-­protected ment. Besides, participants’ cognitive reserve may also server that will only be accessible to the research team. condition their performance on the VR experiments. As such, we will control for these variables in data analyses. Statistical analysis In addition, the gender effect in the treatment outcomes Clinical researchers of the SOCRATES team at the VHIR will be also examined given that the effect of treatment will conduct statistical analyses. Fisher’s exact test for can differ between male and female patients with obesity, categorical variables and independent samples t-­test for as evidenced in previous studies.54 Besides, to obtain continuous variables will be conducted to assess whether a homogeneous sample, we have decided to exclude there will be significant group differences in any of the patients with EDs from our sample. Consequently, the Anastasiadou D, et al. BMJ Open 2022;12:e060822. doi:10.1136/bmjopen-2022-060822 13 Open access results of the study cannot be generalised to people with Correction notice This article has been corrected since it first published. Affiliation obesity and comorbid Binge-­ Eating Disorder, which is 5 has been updated. a common comorbidity.55 Finally, the questionnaires Acknowledgements We would like to thank the SOCRATES Advisory Board and the rest of the members of the SOCRATES consortium for their contributions to the assessing adherence and satisfaction with the virtual expe- project. rience, as well as the ones assessing knowledge acquisi- Contributors MS and PL-­P conceived the study. The whole team developed the tion, have not been validated, or in some cases translated study design, DA reviewed it and wrote the first draft of the manuscript. BS, DCP, into the Spanish context, and this may suppose a further MC, AC, GPP, JV-­DS and JAR-­Q contributed to refinement of the study protocol limitation of the study. and approved the final manuscript. Authorship eligibility for this publication was As a future perspective of the study, in case of results determined in accordance with the European Code of Conduct for Research Integrity (https://allea.org/code-of-conduct/#toggle-id-3). supporting EG1, it would be of scientific interest to carry Funding This study has been funded by the European Union’s Horizon 2020 out a future dismantling study to ascertain the specific Research and Innovation programme (grant agreement no. 951930). The funders contribution of each one of the different ingredients of had no role in study design, data collection and analysis, decision to publish, or the intervention. For example, would ConVRself be so preparation of the manuscript. efficacious without MI training? Regarding the project’s Competing interests MS and BS are the founders of the university spin-­off long-­term impact, the overall objective is to bring the company Virtual Bodyworks. embodiment body-­swapping paradigm treatment into the Patient and public involvement Patients and/or the public were involved in the mainstream and use it for the treatment of a wide range design, or conduct, or reporting, or dissemination plans of this research. Refer to the Methods and analysis section for further details. of behavioural disorders by means of a patient-­centred intervention. This paradigm, if shown to be feasible, can Patient consent for publication Not applicable. drastically change how we approach the treatment of Provenance and peer review Not commissioned; externally peer reviewed. several behavioural disorders both as stand-­alone therapy Supplemental material This content has been supplied by the author(s). It has and as complementary tool to standard CBT and other not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-­reviewed. Any opinions or recommendations discussed are solely those available evidence-­based treatments. of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, ETHICS AND DISSEMINATION terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise. Ethical approval of the study protocol and the informed Open access This is an open access article distributed in accordance with the consent forms was received and approved by the Drug Creative Commons Attribution Non Commercial (CC BY-­NC 4.0) license, which Research Ethics Committee and Research Projects permits others to distribute, remix, adapt, build upon this work non-­commercially, Committee of the Vall d’Hebron University Hospital on 3 and license their derivative works on different terms, provided the original work is August 2021 (PR(AG)224/2021). Patients’ participation properly cited, appropriate credit is given, any changes made indicated, and the use is non-­commercial. See: http://creativecommons.org/licenses/by-nc/4.0/. will be with fully informed written consent, which will be revocable at any time. Findings will be disseminated at ORCID iD a national and international level through peer-­reviewed Dimitra Anastasiadou http://orcid.org/0000-0001-7544-523X journals, reports to the funding body, conferences among the scientific community, events for the general public, the clinical community and the industry and finally, REFERENCES through an active presence on the project’s social media 1 World Health Organization. Obesity and Overweight [Internet], 2020. Available: https://www.who.int/news-room/fact-sheets/detail/​ platforms. obesity-and-overweight 2 European Observatory on Health Systems and Policies. Eurohealth: Author affiliations Addressing Obesity in Europe [Internet]. 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