Design
This study is a pilot randomized control trial (RCT) designed to support the development of a future definitive RCT and it builds upon findings from an initial multiple baseline case series design of EFT for BED (citation blinded for review). Participants were initially randomly allocated to either an EFT treatment intervention or waitlist (12-week clinical monitoring preceding treatment)using a block randomization method(33). This is a commonly used technique in clinical trial design which reduced bias and achieves sample size balance when allocating participants to treatment groups. It is particularly useful for smaller sample sizes and increases the probability that each allocation arm will contain an equal number of individuals by sequencing participant assignments by block.This project was approved by the Queensland University of Technology (QUT) University Human Research Ethics Committee (UHREC) and met the requirements of the National Statement on Ethical Conduct in Human Research (2007). The UHREC Reference number is 1700000986 and all participants provided written informed consent. Consolidated Standards of Reporting Trials (CONSORT) guidelines were fully adhered to – See Figure 1.
Participants
Participants were recruited from local General Practitioners/Primary Care Physicians. Inclusion criteria included the following: being between 18 and 65 years of age, meeting the Diagnostic and Statistical Manual of Mental Disorders: DSM-V American Psychiatric Association – DSM-5 (2013) diagnostic criteria for BED, and possessing sufficient English language skills to provide informed consent and participate in the study without translation. The exclusion criteria included current psychosis, intellectual disability, high suicide risk, drug or alcohol abuse, concurrent treatment for obesity, pregnancy, and the presence of AN or BN.The sample consisted of 21 participants, of whom 17 were female, and 4 were male. The average age was 44.52 (SD=11.89) years and the average age at first binge 18.23 (SD=8.07) years. Ten participants were married or living with someone as married, 5 separated, 3 never married, 2 divorced and 1 widowed. Six participants had graduatedfour-yearcollege, 5 graduated two-year college or trade school, 4 completed grades 7-12 (without graduating high school), 3 graduated high school or high school equivalent, 2 partially completed college/trade school and 1 postgraduate/professional school. Eleven participants were employed full-time, 5part-time employment, 2 keeping house or caregiving full time,2 in school/training and 1 disabled.
Measures
Assessment
Pretherapy diagnostic assessment of BED was based on the Structured Clinical Interview for DSM-5-Research Version - SCID-5-RV (34). At present, there is limited reliability or validity data available for the SCID-5-RV; however, it has demonstrated internal consistency (.80) and test-retest reliability (35). Previous versions of Structured Clinical Interview for DSM-IV Axis I Disorders - SCID-I (36), however, have demonstrated a high level of inter-rater reliability (k = .75) for symptoms and 90% accuracy in diagnosis (37).
Objective binge episodes and days
Changes in objective binge episodes and days (occurrence over the previous 7 days) were assessed using items from the Eating Disorder Examination Questionnaire – EDE-Q-6.0 (38). The EDE-Q-6.0 is a self-report measure of eating disorder psychopathology based on the Eating Disorder Examination Interview (39). It is a widely used measure of eating disorder attitudes and behaviors in both community and clinical populations (40). The EDE-Q-6.0 also provides frequency data on the number of episodes of the eating disorder behavior and the number of days on which the behavior occurred. The items used to measure objective binge episodes (i.e.,a discrete episode of overeating of an objectively large amount of food associated with a feeling of loss of control) in the current study were: “Over the past 7 days how many times have you eaten what other people would regard as an unusually large amount of food (given the circumstances)?” and “On how many of these times did you have a sense of having lost control over your eating (at the time that you were eating)?”. The item used to measure the number of days objective binge episodes occurred was “Over the past 7 days, on how many days have such episodes of overeating occurred (i.e., you have eaten an unusually large amount of food and have had a sense of loss of control at the time)?”. The EDE-Q-6.0 has received support as a reliable and valid measure of eating-related pathology and specific disordered eating behaviors (41, 42). Test-retest reliability across studies ranges from 0.66 to 0.94 for scores on the four subscales (43). The EDEQ-Q-6.0 has demonstrated acceptable levels of internal consistency (α = .90) for the total score in a clinical sample (44). There are no standardized clinical cut-offs (38).
Binge eating psychopathology
Changes in binge-eating psychopathology were assessed using the Binge Eating Scale – BES (45). The BES is a commonly used self-report screening tool for binge eating in clinical practice and research. A total of 16 items are rated using 3-4 separate responses assigned a numerical value. An example of an item is “(a.) I feel capable to control my eating urges when I want to; (b.) I feel like I have failed to control my eating more than the average person; (c.) I feel utterly helpless when it comes to feeling in control of my eating urges; (d.) Because I feel so helpless about controlling my eating I have become very desperate about trying to get in control.” Total scores range from 0 to 46, with higher scores indicating more severe binge-eating symptoms. The BES has demonstrated high test-retest reliability (r=.71) and internal consistency (α=.85) in an obese population (46), good 2-week test-retest reliability (r=.87) in a behavioral weight loss sample (47), high internal consistency (α = .91) in a BED sample (48) andgood construct reliability and convergent validity (49). Standardized cut-off scores are as follows: ≤ 17 = no binge eating, 18–26 = mild to moderate binge eating, and ≥ 27 = severe binge eating (45).
Psychiatric comorbidity
Anxiety and depression were assessed using the Beck Anxiety Inventory – BAI (50) and Beck Depression Inventory-II – BDI-II (51). The BAI is one of the most used clinical self-rating scales for measuring the intensity of anxiety (52). Respondents are presented with a list of 21 common symptoms of anxiety and indicate how much they have been bothered by that symptom during the past month. Items are rated on a scale of 0 = not at all to 3 = severely. The total score is calculated by summing the ratings for the 21 items with amaximum possible score of 63. The BAI has high internal consistency (.93) and good test-retest reliability (.75) (53), in addition to robust convergent and discriminant validity (54). Standardized cut off scores are as follows: 0-21 = low anxiety, 22-35 = moderate anxiety and >36 = potentially concerning levels of anxiety.
The BDI-II is one of the most widely adopted measures of depressive symptoms (55). The BDI-II measures both cognitive-affective (negative mood or negative affect) and somatic (fatigue or loss of energy) dimensions of depressive symptoms (56). Respondents read 21 groups of statements and then choose the one statement in each group that best describes the way he/she felt in the previous two weeks. Items are rated on a scale of 0 to 3, with higher ratings indicating more severe depressive symptoms. The total score is calculated by summing the 21 items, and the maximum possible score is 63. The BDI-II has sound psychometric properties with high internal consistency (α=.89) within the BED population. (9). It also has high test-retest reliability (r=.73 to .96)and sound concurrent, content, and structural validity across other populations (57). Standardized cut-offs are as follows: 0-13 = minimal depression, 14-19 = mild depression, 20-28 = moderate depression and 29-63 = severe depression (53).
Therapy retention
Participants who completely discontinued attendance were considered dropouts.
Procedures
Participants were initially telephone-screened for BED based on diagnostic criteria, according to DSM-5 (2013). Twenty-eight participants were telephone-screened, of which five did not meet the diagnostic criteria for BED. Twenty-three participants meeting the diagnostic criteria for BED then completed the SCID-5-RV administered by a research assistant with training in clinical psychology. All met the inclusion criteria, but 1 participant chose not to participate due to being unable to commit fully to weekly treatment sessions, and 1 participant did not respond to contact attempts. Twenty-oneparticipants were randomly allocated to either an EFT intervention or 12-week waitlist using a block randomization methodby a statistician independent to the research team.
Participants allocated to the EFT intervention initially completed the BES, EDE-Q-6.0, BDI-II and BAI at pretherapy (Week 0). The BES and EDE-Q-6.0 were completed weekly during treatment (Weeks 1-12), and the BES, EDE-Q-6.0, BDI-II and BAI were completed at follow-up (Weeks 16, 20 and 24). Participants allocated to the waitlist control completed the BES, EDE-Q-6.0, BDI-II and BAI at pretherapy (Week 0), and then again 12 weeks later post waitlist period completion. Waitlist control participant then commenced 12 weekly treatment sessions and followed the same protocol as participants initially allocated to the treatment intervention. The therapist was blind to all assessments and randomizations of the participants.
Treatment
Treatment incorporated 12 weekly one-hour sessions of EFT for maladaptive emotionsover three months. The treatment manual was initially adapted from Wnuk et al. (30) by (citation blinded for review)in a series of case studies exploring the use of individual EFT to treat BED. Phase 1 of the treatment focused on promoting awareness of emotions, welcoming and accepting emotions, putting emotions into words, and identifying primary emotions. Phase 2 focused on evaluating whether the primary emotion was adaptive or maladaptive, identifying destructive emotions, accessing other adaptive emotions and needs, and transforming maladaptive emotion schemes. Six main marker guided interventions were used in treatment in line with EFT protocol (25,27). These were:1. Empathic attunement and validation for vulnerability and establishing thetherapeutic alliance 2. Evocative unfolding for problematic reactions 3. Experiential focusing for unclear feelings 4. Two-chair dialoguesfor self-critical splits 5. Two-chair enactmentfor self-interruptive splits and 6. Empty chair work for unfinished business.
Therapist
The therapist was the first author, a Clinical Psychologist with 25 years of practice experience who had undergone Level 1, 2 and 3 training in EFT at the York University Psychology Clinic with the primary developer of this approach, Distinguished Professor
Emeritus, Leslie Greenberg. The therapist had approximately four years of EFT-specific practice experience before the study and was not involved in the initial treatment/waitlist randomization process, data collection before or during the study, or data analysis until after the study. Supervision was provided by Distinguished Professor Emeritus, Leslie Greenberg who was also a co-author of the original treatment manual used as a basis for therapy within the current study. Adherence to EFT protocol was reviewed - and rectified where necessary - during supervision based on video recordings of study treatment sessions.
Statistical Analyses Plan
Initially, abetween-groupexamination was conducted in relation to any significant differences between the 10 participants in the EFT intervention and 10 participants in the waitlist control on demographics at baseline. A series of 2 (Group) x 2 (Time) repeated measures analyses of variance (ANOVA) were then used to test the hypothesis that those receiving the treatment would demonstrate a greater degree of improvement on primary outcomes measures relating to objective binge episodes and days, and binge eating psychopathology compared to participants on the waitlist.. Following the between-group analysis, a within-group examination was then conducted in relation to any significant differences between the 20 participants who completed treatment on demographics. A series of within-groups repeated measures analyses of variance (ANOVA) was then conducted to test the hypothesis that participation in the EFT intervention would result in significant improvements in the primary and secondary outcome measures from pre to post-therapy and then maintained at each follow-up period