A Pilot Study Evaluating Practical Body Image (PBI): A Body Image Therapy With Mirror Exposure for Adolescent Inpatients With Anorexia Nervosa
A Pilot Study Evaluating Practical Body Image (PBI): A Body Image Therapy With Mirror Exposure for Adolescent Inpatients With Anorexia Nervosa
Background:
Dysfunctional body image is a strong predictor of maintenance and relapse in anorexia nervosa, making treatment of such clinically and financially important. Studies have shown that cognitive behavioural based group therapies and mirror exposure interventions are effective in improving body image in adults with eating disorders; however research into individual body image treatments for adolescents with anorexia nervosa is limited.
Practical Body Image (PBI) is a novel, manualised, individual treatment designed for adolescents with anorexia nervosa for which the evidence base is not yet established. This research will therefore contribute to the evidence base for the treatment of body image in adolescents with anorexia nervosa and inform the effectiveness of a new treatment. The research will be funded by Newbridge House, an inpatient unit for children and adolescents with eating disorders.
Research Questions:
Does Practical Body Image improve body image and psychological wellbeing in adolescent inpatients with anorexia nervosa?
Does a mirror exposure intervention improve body image and psychological wellbeing in adolescent inpatients with anorexia nervosa after completion of the rest of the programme?
Design:
Patients aged 11-18, fulfilling DSM-V criteria for anorexia nervosa and receiving treatment at Newbridge House will be recruited for participation in the research study. Participants will be randomly allocated to either a case or control group. Allocation will be based on a non-blind randomised controlled trial. Cases will receive PBI in addition to treatment as usual and will be compared with controls who just receive treatment as usual. Both groups will complete a set of questionnaires at baseline, 7 weeks and 10 weeks.
PRINCIPAL NULL HYPOTHESIS PBI will have no impact on body image or psychological wellbeing in adolescent inpatients with anorexia nervosa compared to just TAU.
SECONDARY NULL HYPOTHESIS Mirror exposure will have no effect on body image or psychological wellbeing in adolescent inpatients with anorexia nervosa after completion of the rest of PBI.
PRINCIPAL ALTERNATIVE HYPOTHESIS PBI will improve body image and psychological wellbeing in adolescent inpatients with anorexia nervosa compared to just TAU.
SECONDARY ALTERNATIVE HYPOTHESIS Mirror exposure will improve body image and psychological wellbeing in adolescent inpatients with anorexia nervosa after completion of the rest of PBI.
The alternative hypotheses were chosen based previous research which shows that cognitive behavioural techniques and mirror exposure are effective in improving body image disturbance and psychological wellbeing in adults with anorexia nervosa. This study aims to generate hypotheses about which specific elements of body image (i.e. body avoidance, body acceptance, body anxiety or weight and shape concern) and psychological wellbeing (i.e. self esteem, anxiety and depression) change after completion of PBI.
DESIGN
The principal hypothesis will be tested using a between subjects design (PBI vs no PBI) with treatment as the independent variable. The case group will receive TAU as well as PBI and the control group will receive just TAU. The outcomes from self-report measures completed at 10 weeks will be compared between the case and control groups to answer the principal research question.
The secondary hypothesis will be tested using a within subjects design (before mirror exposure vs after mirror exposure) with mirror exposure as the independent variable. The case group will complete self-report measures at week 7 before commencing mirror exposure in addition to week 10. This will allow comparison of outcomes before mirror exposure to after mirror exposure to answer the secondary research question.
The dependent variables are body image (including body avoidance, acceptance, anxiety and weight and shape concerns) and psychological wellbeing (including self-esteem, anxiety and depression) as measured by self-report questionnaires.
This experimental design has been chosen as it allows for the comparison of PBI vs no PBI as well as a comparison between outcomes before mirror exposure and outcomes after mirror exposure. The choice of this design was influenced by a desire to provide an evidence base for this novel treatment and to determine whether mirror exposure has any additional benefit for adolescents with anorexia nervosa.
METHOD
Participants will be inpatients, aged 11 - 18, fulfilling DSM-IV criteria for anorexia nervosa and receiving treatment at Newbridge House child and adolescent inpatient eating disorder unit. A convenience sampling method will be used and participants will be randomly allocated to either a 'case' group to complete TAU plus PBI or a 'control' group to complete only TAU using an Excel formula. A control group (TAU) was included in order to compare outcomes of those who complete PBI with outcomes of those who do not. This is because the principal aim of the study is to evaluate the effectiveness of this novel treatment and there is insufficient evidence to support the introduction of PBI without conducting a study of this kind. This is especially necessary given that the research site is an inpatient unit and all participants will be receiving other therapies alongside the treatment being tested.
Forty participants will be recruited in total (twenty in each group). As this is a pilot study no power calculation could be conducted and this sample size was agreed as sufficient to generate data to inform a power calculation for future research. Participants will be identifiable by a unique code created using the letters 'TAU+PBI' or 'TAU' followed by a number relating to the order in which they were recruited (1-20). Participants will be approached to take part in the research when they reach 90% of their healthy weight. All patients on the unit who fulfill the framework of inclusion and exclusion criteria will be asked for their informed written consent to participate after reading a research information sheet. For patients under age 16, parents will also be given a research information sheet and consent form and asked to provide written informed consent.
TIMETABLE
All stages will take place on site at Newbridge House.
STAGE 0 (Recruitment)
Patients will be recruited as described above and an Assistant Psychologist will meet with them to read through the research information sheet and request informed written consent. For patients under 16, written parental consent will also be sought and parents will be given an information sheet and consent form prior to commencement of the study. Patients and parents will be given 7 days to consider their decision to consent to participate in the research. Patients for whom we receive consent will then be randomly allocated to either the case or control group using an Excel formula. Patients who do not consent, or for whom parental consent is not received, will not be included in the study and will receive TAU which will be identical to that delivered to controls. Patients declining to participate will be asked for permission to use demographic and routine clinical data to test if there are any significant differences between participants versus non-participants, and to examine whether the sample is representative.
Stage 1 (Week 1)
All participants will be asked to complete a set of self-report measures in week 1 (baseline). For participants in the case group, PBI will then commence and take place over 7 weeks alongside TAU. For participants in the control group TAU will continue.
STAGE 2 (Week 7)
Stage 2 will take place 7 weeks after completion of baseline measures in between session 7 and 8 of PBI. At this stage the same measures will be completed by participants in the case group only.
For participants in the case group, the mirror exposure part of PBI will commence and take place twice a week, over 3 weeks alongside TAU. For participants in the control group TAU will continue.
STAGE 3 (Week 10)
Stage 3 will take place 10 weeks after completion of baseline measures. At this stage those in the case group will have completed the PBI intervention. The same measures will be completed for the last time by participants in both the case and control groups.
Participant feedback about their experiences of the programme will also be sought.
STAGE 4 (Data analysis)
Researchers will input raw data from completed outcome measures onto an SPSS spreadsheet. Data will then be analysed and interpreted.
STAGE 5 (Report write up)
The final report will be written for publication.
INTERVENTION The intervention will comprise of 14 sessions of individual body image therapy using a cognitive behavioural approach over a 10 week period. The therapy has been protocolised into a treatment manual known as PBI, and will be administered by Assistant Psychologists employed at Newbridge House receiving weekly supervision from a Clinical Psychologist.
PBI is based on a cognitive behavioural model of body image addressing thoughts, feelings, behaviours and misperceptions. PBI is designed to be administered over 6 weekly sessions followed by 8 twice weekly sessions over 4 weeks. Therapists delivering the programme will have time to read through the manual and attend weekly peer supervision to support adherence to the protocol. Therapists will require some background knowledge of the nature of body image in eating disorders and some knowledge of basic CBT principles. They will also receive weekly clinical supervision by a trained CBT therapist. The sessions are structured and laid out in the following overview:
Week 1, Session 1: My Body Image
Week 2, Session 2: Body Perception
Week 3, Session 3: Testing Beliefs
Week 4, Session 4: Body Avoidance Outing 1
Week 5, Session 5: Body Avoidance Outing 2
Week 6, Session 6: Review and Reflection
Week 7, Session 7: Introduction to Mirror Use Session 8: Mirror Exposure 1
Week 8, Session 9: Mirror Exposure 2 Session 10: Mirror Exposure 3
Week 9, Session 11: Mirror Exposure 4 Session 12: Mirror Exposure 5
Week 10,Session 13: Mirror Exposure 6 Session 14: Ending Session
Week 10, Session 13: Mirror Exposure, Session 14: Ending session
Inclusion Criteria:
Exclusion Criteria: