JMIR FORMATIVE RESEARCH

Hamatani et al

Original Paper

Internet-Based Cognitive Behavioral Therapy via Videoconference
for Patients With Bulimia Nervosa and Binge-Eating Disorder:
Pilot Prospective Single-Arm Feasibility Trial
Sayo Hamatani1,2, PhD; Noriko Numata1, PhD; Kazuki Matsumoto1, PhD; Chihiro Sutoh3, MD, PhD; Hanae Ibuki1,
MA; Keiko Oshiro1, PhD; Mari Tanaka3, MMSc; Rikukage Setsu3,4, MD, PhD; Yohei Kawasaki5, PhD; Yoshiyuki
Hirano1, PhD; Eiji Shimizu1,3,6, MD, PhD
1

Research Center for Child Mental Development, Chiba University, Chiba, Japan

2

Japan Society for the Promotion of Science, Tokyo, Japan3

Department of Cognitive Behavioral Physiology, Graduate School of Medicine, Chiba University, Chiba, Japan

4

Koutokukai Sato Hospital, Yamagata, Japan

5

Biostatistics Section, Clinical Research Center, Chiba University Hospital, Chiba, Japan

6

Cognitive Behavioral Therapy Center, Chiba University Hospital, Chiba, Japan

Corresponding Author:
Noriko Numata, PhD
Research Center for Child Mental Development
Chiba University
1-8-1, Chuo-ku
Chiba
Japan
Phone: 81 43 226 207
Email: n_numata@chiba-u.jp

Abstract
Background: A major problem in providing mental health services is the lack of access to treatment, especially in remote areas.
Thus far, no clinical studies have demonstrated the feasibility of internet-based cognitive behavioral therapy (ICBT) with real-timetherapist support via videoconference for bulimia nervosa and binge-eating disorder in Japan.
Objective: The goal of the research was to evaluate the feasibility of ICBT via videoconference for patients with bulimia nervosaor binge-eating disorder.
Methods: Seven Japanese subjects (mean age 31.9 [SD 7.9] years) with bulimia nervosa and binge-eating disorder received 16
weekly sessions of individualized ICBT via videoconference with real-time therapist support. Treatment included CBT tailoredspecifically to the presenting diagnosis. The primary outcome was a reduction in the Eating Disorder Examination Edition 16.0D(EDE 16D) for bulimia nervosa and binge-eating disorder: the combined objective binge and purging episodes, objective binge
episodes, and purging episodes. The secondary outcomes were the Eating Disorders Examination Questionnaire, Bulimic
Investigatory Test, Edinburgh, body mass index for eating symptoms, Motivational Ruler for motivation to change, EuroQol-5
Dimension for quality of life, 9-item Patient Health Questionnaire for depression, 7-item Generalized Anxiety Disorder scale foranxiety, and Working Alliance Inventory–Short Form (WAI-SF). All outcomes were assessed at week 1 (baseline) and weeks 8(midintervention) and 16 (postintervention) during therapy. Patients were asked about adverse events at each session. For the
primary analysis, treatment-related changes were assessed by comparing participant scores and 95% confidence intervals using
the paired t test.
Results: Although the mean combined objective binge and purging episodes improved from 47.60 to 13.60 (71% reduction)and showed a medium effect size (Cohen d=–0.76), there was no significant reduction in the combined episodes (EDE 16D –41;
95% CI –2.089 to 0.576; P=.17). There were no significant treatment-related changes in secondary outcomes. The WAI-SF scoresremained consistently high (64.8 to 66.0) during treatment.
Conclusions: ICBT via videoconference is feasible in Japanese patients with bulimia nervosa and binge-eating disorder.
Tr i a l
Registration:
UMIN
Clinical
Tr i a l s
Registry
UMIN000029426;
https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000033419
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Hamatani et al(JMIR Form Res 2019;3(4):e15738) doi: 10.2196/15738
KEYWORDS
bulimia nervosa; binge-eating disorder; cognitive behavioral therapy; internet-based cognitive behavioral therapy; videoconference

Introduction
Eating disorders characterized by hyperphagia include bulimia
nervosa and binge-eating disorder [1]. The prevalence of bulimia
nervosa in Japan is estimated to be 1.9% to 2.9% [2]. Bulimia
nervosa is a psychiatric disorder characterized by repeatedovereating and inappropriate compensatory behavior [1]. Like
bulimia nervosa, binge-eating disorder is characterized byrepeated episodes of hyperphagia but without the repetitive
inappropriate compensatory behavior seen in bulimia nervosa[1]. Several meta-analyses of randomized controlled trials(RCTs) that included wait list controls have reported thatcognitive behavioral therapy (CBT) is effective for bulimia
nervosa and binge-eating disorder [3,4-7]. Our research grouphas recently conducted a single-arm study that confirmed theeffectiveness of guided self-help CBT for Japanese patientswith bulimia nervosa [8]. Although previous studies have shown
the effectiveness of CBT for bulimia nervosa and binge-eating
disorder, the patients who reside in rural areas or far from
specialized treatment institutions cannot receive evidence-based
therapy such as CBT. Comorbidities such as panic disorder andagoraphobia make it difficult for patients to go out, and patientswith severe depression are easily tired, making it difficult forpatients to attend CBT sessions once a week. Therefore, it isnecessary to devise methods to provide the approved treatment
at home for all patients.
Recently, CBT for patients with eating disorders has been
increasingly provided via the internet [9-13]. Most
internet-based CBT (ICBT) clinical trials provided to patientsare guided by the therapist via email, but not in real time. A
systematic review of 8 studies in patients with bulimia nervosa,binge-eating disorder, or eating disorder not otherwise specified(EDNOS) suggested that ICBT without videoconference has
the effect of reducing the frequency of overeating [14]. Further,a systematic review including 22 RCTs, 2 controlled studies,and 16 uncontrolled studies found evidence for the efficacy ofguided ICBT for bulimia nervosa patients; however, only one
RCT included ICBT via videoconference [15]. Hence, more
research is needed to determine the efficacy and limitations of
ICBT via videoconference. There have been 2 case series andone clinical trial of ICBT via videoconference reported
specifically in patients with eating disorders [16-18]. A caseseries with ICBT via videoconference was performed on twopatients with bulimia nervosa in the United States [16]. A caseseries of ICBT via videoconference was conducted in Scotland
and included 12 patients: bulimia nervosa (n=5), anorexia
nervosa (n=1), and EDNOS (n=6, including 3 with binge-eating
disorder) [17]. A total of 67% of these patients rated ICBT via
videoconference favorably because of the convenience ofreceiving treatment in their area, feeling more in control, andfeeling less intimidated than in a face-to-face session. An RCT
was performed in the United States and included 128 patientswith bulimia nervosa and EDNOS who were assigned tohttp://formative.jmir.org/2019/4/e15738/

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face-to-face CBT or ICBT via videoconference [18]. The
posttreatment symptom rating scale score and symptomatic
improvement showed no significant difference between ICBTvia videoconference and face-to-face CBT.
The evidence for the effectiveness of ICBT via videoconference
for bulimia nervosa and binge-eating disorder appears promising
but is limited and has only been demonstrated in Western
populations. No clinical trials of ICBT via videoconference
have been conducted in non-Western populations, including inJapan. The aim of this study was to evaluate the feasibility of
ICBT via videoconference for Japanese patients with bulimia
nervosa and binge-eating disorder by evaluating theposttreatment change in symptom evaluation scores.

Methods
Study Design
This prospective single-arm open trial was performed in theoutpatient clinic at the Cognitive Behavioral Therapy Centerof Chiba University Hospital between October 2017 and March
2019. Because of the deadline for grant support, we could notextend the recruitment period. Since this trial was the first to
employ an individual ICBT via videoconference intervention
design against bulimia nervosa and binge-eating disorder inJapan, a single-arm trial examining feasibility rather thaneffectiveness was considered to be an appropriate design.

Ethics Statement
The study was approved by the institutional review board of
Chiba University Hospital (reference number G29028) andregistered at University Hospital Medical Information Network
Clinical Trials Registry [UMIN000029426]. Written informed
consent was obtained from all patients who participated in the
study after they had been fully informed about the study
protocol.

Study Participants
Patients were enrolled in the study if they met the following
inclusion criteria: assessment by a senior psychiatrist at Chiba
University Hospital using the Mini International
Neuropsychiatric Interview [19,20] and a primary diagnosis ofbulimia nervosa or binge-eating disorder according to the
Diagnostic and Statistical Manual of Mental Disorders, 5th
Edition (DSM-5) criteria, females aged 16 to 65 years; BMI>17.5 kg/m2, and access to the internet at home. A comorbid
diagnosis was accepted if it was clearly secondary to bulimia
nervosa and binge-eating disorder. Exclusion criteria involved
those who were expected to interrupt CBT due to the following
comorbidities: organic brain damage, dementia, psychotic
disorders, bipolar disorder, current high risk of suicide,substance abuse or dependence, antisocial behaviors, and criticalphysical disease. In principle, no drug changes were allowed
during the trial.
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Hamatani et al

Cognitive Behavioral Therapists and Quality Control

Depression and Generalized Anxiety

A total of 16 one-on-one sessions were conducted between
therapists and patients. The therapists were three clinicalpsychologists and one nurse; all therapists were certified public
psychologists. All therapists had completed a CBT training
course (ie, Chiba–Improving Access to Psychological Therapies
project) [21].

The presence and severity of symptoms of depression
experienced in the previous 2 weeks was evaluated using thePHQ-9 [27,28]. The self-administered questionnaire items arescored on a 4-point Likert-scale (0=not at all, 1=on several days,
2=half or more of the days, 3=almost every day). The minimumscore is 0 and the maximum score is 27 (0 to 4 indicates nosymptoms, 5 to 9 indicates mild symptoms, 10 to 14 indicatesmoderate symptoms, 15 to 19 indicates moderate to severe
symptoms, and 20 to 27 indicates severe symptoms). The cutoff
score for clinically significant depressive symptoms is 10. The
presence and severity of generalized anxiety disorder wasassessed using the GAD-7 [29,30], a self-administeredquestionnaire that assesses the severity of generalized anxiety
disorder in the previous 2 weeks on a 4-point Likert scale (0=not
at all, 1=one episode, 2=on half or more days, 3=almost everyday). The minimum score is 0 and maximum score is 21 (0 to
4 indicates no symptoms, 5 to 9 indicates mild symptoms, 10
to 14 indicates moderate symptoms, and 15 to 21 indicatessevere symptoms). The cutoff score for clinically significant
symptoms of anxiety is 10.

Primary Outcome
The primary outcome was the change from week 1 (baseline)
to week 16 (postintervention) in frequency of objective bingeand purging episodes assessed by the Eating Disorder
Examination Edition 16.0D (EDE 16D) [22,23]. It contains
subscales that reflect the frequency of episodes of a particularbehavior, frequency of days on which the behavior occurred,and psychopathologic severity of the eating disorder. In thisstudy, we used only the frequency of episodes of behavior,
which is an important feature of eating disorders. The frequencyof objective binge episodes over 28 days, frequency of purging
episodes (vomiting, laxative abuse, and diuretic abuse), andfrequency of combined objective binge and purging episodes
were calculated. Each subject was assessed at week 1 (baseline)
and week 16 (postintervention).

Secondary Outcomes
Each patient was also assessed using the Eating Disorders
Examination Questionnaire (EDE-Q) [23,24], Bulimic
Investigatory Test, Edinburgh (BITE) [25,26], BMI, Patient
Health Questionnaire (PHQ-9) [27,28], Generalized Anxiety
Disorder scale (GAD-7) [29,30], EuroQol-5 Dimensions(EQ-5D-5L) [31,32], Working Alliance Inventory-Short Form
(WAI-SF) [33], and Motivational Ruler [34] at weeks 1(baseline), 8 (midintervention), and 16 (postintervention).

Psychopathologic Severity of Bulimia Nervosa or
Binge-Eating Disorder
The psychopathologic severity of bulimia nervosa or
binge-eating disorder was assessed using the EDE-Q [23,24],
which is a self-contained, 28-item questionnaire derived fromthe EDE. The EDE-Q is scored on a 7-point Likert scale (0 to6) on which a score of ≥4 indicates a clinical range. The global
score on the EDE-Q is the sum of the 4 subscale scores(restraint, eating concern, shape concern, and weight concern)
divided by 4. The presence and severity of symptoms of bulimia
nervosa and cognitive and emotional signs and symptoms
associated with hyperphagia were assessed using the BITE
[25,26]. The BITE is a self-administered 33-item questionnairethat consists of 30 symptom subscales (eg, “Would you say thatfood dominated your life?”) and 3 severity subscales (“I don't
eat all day,” “how to lose weight,” and “frequency ofovereating”). Symptom subscale items are organized in yes/noformat, and severity subscale items are organized in a
Likert-type response format (5-point or 7-point, depending on
the item). The symptom subscale has a minimum score of 0 anda maximum score of 30. However, the maximum severity
subscale score is 39. The symptom subscale has 20 or morepoints ranging from “altered pattern of behavior” to “highprobability of bulimia nervosa.” A severity subscale score of≥5 indicates a clinically significant eating disorder.
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Quality of Life
Quality of life was measured using the EQ-5D-5L questionnaire[31,32]. The EQ-5D-5L is self-administered with items that arescored from 0 (death) to 1 (in good health).

Therapeutic Relationship and Motivation
This study was the first to use ICBT via videoconference toprovide therapist support for Japanese patients with bulimia
nervosa and binge-eating disorder. ICBT via videoconferencing
used the following scales to determine whether motivation andtreatment compliance could be established. The strength of thetherapeutic alliance was assessed using the WAI-SF [33]. This
self-administered questionnaire consists of 12 items that measure
3 factors (ie, agreement on the task of treatment, agreement on
the goal of treatment, and a bond between the therapist andpatient). The WAI-SF is scored on a 7-point Likert scale; theminimum score is 12, and the maximum is 84. Motivation fortreatment was assessed using the Motivational Ruler [34]. This
instrument is a self-administered questionnaire containing 2
items (“How important is it for you to change and recover fromyour eating disorder?” and “How confident are you in yourability to change and recover from your eating disorder?”) thatare measured on a 10-point Likert scale. The minimum scoreis 2, and the maximum score is 20.

Interventions
Participants entered the Web conference room by clicking on
the URL in the email sent by the therapist. The intervention was
performed for 50 minutes once a week for 16 weeks. The
protocol included the following modules: assessment;
explanation of CBT, motivation and goal setting, education on
bulimia nervosa and how to keep a dietary diary, psychologicaleducation and monitoring for overeating behavior, psychologicaleducation and monitoring of diet, reforming of dietary habits(mindful diet), psychological education and self-monitoring ofcompensatory behavior, stress management and relaxation,
understanding perfectionism, interpersonal relationships and
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assertions, acquisition of skills to associate with emotions(emotional adjustment, mindfulness, tolerance of distress,
alexithymia), attention to body image, and prevention ofrecurrence. These modules are a development of those used in
our previous study of face-to-face CBT for patients with bulimia
nervosa in Japan [8,35].

Visual Aids
The use of visual aids promotes the learning process byenhancing motivation and understanding of complex concepts[36]. To deepen understanding, therapists presented a visual aid
that consisted of several slides containing the key concepts of
CBT using the screen-sharing feature of the videoconferencing
software. After each session, study participants were emailed
a set of password-protected homework slides.

Hardware
The therapists used a Surface Pro 2 computer (Microsoft Corp),
which is a 2-in-1 detachable system that runs on Windows 10
Pro (Microsoft Corp). This computer has a display size of 10.6
inches and a resolution of 1920×1080 pixels.

Hamatani et al

Statistical Analysis
Statistical analysis and reporting of this trial were conducted inaccordance with the Consolidated Standards of Reporting Trials
of Electronic and Mobile Health Applications and Online
TeleHealth (CONSORT-EHEALTH) guidelines [38]. The
primary analysis compared differences in objective binge andpurging on the EDE 16D between baseline and 16 weeks for
all patients with bulimia nervosa or binge-eating disorder using
the paired t test, and 95% confidence intervals were calculated.
Analysis of secondary outcomes was performed in the sameway. We also calculated the effect size of treatment using Cohend, calculated as the mean difference after treatment divided by
the pooled standard deviation. A Cohen d>0.20 was used as thecriterion for a small effect, a value >0.50 as a medium effect,and >0.80 as a large effect [39]. All P values were 2-sided andthose <.05 were considered statistically significant. All statisticalanalyses were performed with SAS software version 9.4 (SASInstitute Inc).

Results

Videoconferencing Software

Recruitment

A total of 3 licenses for videoconferencing software (Cisco
Webex, Cisco Systems) were used. This system has International
Organization for Standardization 27001 certification (forhandling information security) and Statement on Standards for
Attestation Engagements Number 16–compliant certification
issued by a third party. Cisco Webex’s use of a switching
network with 128-bit Secure Sockets Layer encryption andpublic key infrastructure is considered to have resolved the
problem of security [37]. We determined that Cisco Webex canbe trusted for the purposes of this research because the softwareis stable and secure and protects personal information well.

Figure 1 shows the flow of participants through the study. Tenpatients applied to participate in the study via our website. Afterscreening by email and telephone, 2 patients failed to meet theinclusion criteria and were excluded (BMI <17.5 kg/m2); 8
patients attended a baseline face-to-face assessment and wereenrolled in the study. After enrollment, 1 patient declined toparticipate, and 2 patients dropped out during the intervention(1 refused to perform the homework; 1 could not combine thetask assigned with her daily work). The analysis included thedata of these 2 patients.

Adverse Events
At the end of each session, therapists asked patients about theiroverall physical and mental state of health and instructed themto report any adverse events experienced after the intervention
by email. No mental or physical adverse events were reported.

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Demographic and Clinical Characteristics
The study population comprised 7 women of mean age 31.9
(SD 7.9; range 21-43) years. Their demographic and clinicalcharacteristics are shown in Table 1. Five participants continued
to receive pharmacotherapy during the trial (triazolam, n=1;
flunitrazepam, n=1; clonazepam, n=1; sertraline, n=1; sodium
valproate, n=1; quetiapine fumarate, n=1; aripiprazole, n=1;
and clotiazepam, n=1).

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Hamatani et al

Figure 1. Flow of participants.

Table 1. Clinical and demographic characteristics of the study participants (n=7).
Characteristic

Participant

Value

1

2

3

4

5

6

7

Sex

FemaleFemaleFemaleFemaleFemaleFemaleFemale—Age, mean (SD)

26

43

31

29

43

24

27

31.9 (7.9)

Education in years, mean (SD)

14

15

17

11

12

12

16

14.1 (2.4)

Duration of eating disorder in years, mean (SD) 12

17

17

12

19

5

2

12.0 (6.4)

BMI (kg/m2), mean (SD)

17.8

22.2

20.4

18.4

36.0

20.0

30.0

23.5 (6.8)

Diagnosis

Bulimia
nervosa

Bulimia
nervosa

Bulimia
nervosa

Bulimia
nervosa

Binge-eating Bulimia
disordernervosa

Binge-eating —disorderMajor depressive disorder

—

—

—

X

X

—

—

2 (29)

Dysthymia

—

—

—

X

—

—

X

2 (29)

Agoraphobia

—

—

—

—

X

—

—

1 (14)

Social anxiety disorder

X

—

—

—

—

—

X

2 (29)

Obsessive-compulsive disorder

—

—

X

—

—

—

—

1 (14)

Posttraumatic stress disorder

—

—

X

—

—

X

—

1 (14)

Generalized anxiety disorder

—

—

—

X

—

X

—

2 (29)

Schizophrenia

—

—

—

—

—

—

X

1 (14)

Major depressive disorder

—

—

—

—

X

—

—

1 (14)

Manic episode

—

—

—

—

X

—

X

2 (29)

Autism spectrum quotient, mean (SD)

28

13

15

33

33

19

17

22.6 (7.9)

Estimated IQ by JARTa, mean (SD)

106

106

98

89

94

100

106

99.9 (6.2)

Psychotropic drug, n (%)

—

—

X

X

X

X

X

5 (71)

Completer, n (%)

X

X

X

X

X

—

—

5 (71)

Comorbidity, n (%)

Past history, n (%)

a

JART: Japanese Adult Reading Test.

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Primary Outcome
Figure 2 shows the change in the combined objective binge andpurging episodes on the EDE 16D, and Figure 3 shows thedetailed transition of symptoms for each patient. Although themean combined episodes improved from 47.0 to 13.6 (71%
reduction) and showed a medium effect size (Cohen d=–0.76),
there was no significant reduction in the combined objective
binge and purging episodes (EDE 16D −41; 95% CI −2.09 to
0.58; P=.17; Table 2). The frequency of objective binge episodes
improved from 23.6 to 6.8 (71% reduction) and showed a large
effect size (Cohen d=–0.82); no significant reduction in objective
binge episodes (EDE 16D –20.60; 95% CI –2.18 to 0.53; P=.14).

Hamatani et al
The frequency of purging episodes improved from 23.4 to 6.8(71% reduction) and showed a medium effect size (Cohen
d=–0.70); no significant reduction in the frequency of purging
episodes (EDE 16D –20.40; 95% CI 2.01 to 0.62; P=.19).
Additionally, abstinence was defined as none of these behaviors
reported in the previous 28 days [18]. The abstinence rate fromobjective binge-eating, purging, and combined objective bingeand purging was 43% (3/7).

Secondary Outcomes
Table 3 shows the change in secondary outcomes during thestudy. There were no significant changes in results.

Figure 2. Changes in frequency of objective binge and purging episodes during treatment. Bars indicate 1 standard deviation.

Figure 3. Change in number of episodes during treatment.

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Table 2. Changes in the frequency of objective binge and purging episodes from pre- to post–internet-based cognitive behavioral therapy.
Episode and assessment time pointnMean (SD)

Cohen d (n=5)

95% CI

P value

Combined objective binge eating and purging episodes

—

—

–0.76

–2.09 to 0.58

.17

Assessment

7

72.6 (45.7)

Week 1747.0 (45.6)

—

—

—

Week 87

29.2 (40.9)

Week 165

13.6 (22.6)

—

—

—

—

—

–0.82

–2.18 to 0.53

.14

Assessment

7

32.6 (15.8)

Week 1

7

29.2 (40.9)

—

—

—

Week 869.7 (11.9)

Week 165

6.8 (11.3)

—

—

—

Purging episodes

—

—

–0.70

–2.01 to 0.62

.19

Assessment7

40.0 (31.5)

Week 17

13.6 (22.6)

—

—

—

Week 86

19.5 (31.6)

Week 165

6.8 (11.3)

—

—

—

Objective binge eating episodes

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Table 3. Changes in psychological test scores from pre- and post–internet-based cognitive behavioral therapy.
Test name and assessment time pointnMean (SD)

Cohen d (n=5)

95% CI

P value

—

—

–0.48

–1.158 to 0.204.35

Assessment

7

3.2 (1.7)

—b

—

—

Week 17

2.2 (1.3)———

Week 86

1.8 (1.3)———

Week 165

1.3 (1.1)———

Restraint subscale

—

—

–0.33

–1.401 to 0.741.50

Assessment

7

3.1 (1.9)———

Week 17

2.3 (1.9)———

Week 86

1.6 (1.4)———

Week 165

1.4 (0.9)

—

—

—

—

—

–1.07

–1.957 to –0.179.08

Assessment

7

3.3 (1.8)———

Week 17

1.9 (1.7)———

Week 86

1.2 (1.4)———

Week 165

0.7 (0.2)

—

—

—

—

—

0.01

–0.273 to 0.297.98

Assessment

7

3.4 (1.9)———

Week 17

2.5 (2.0)———

Week 86

2.3 (2.0)———

Week 165

1.6 (1.8)

—

—

—

—

—

0.26

0.044 to 0.484.59

Assessment7

3.0 (2.0)———

Week 17

2.2 (2.0)———

Week 86

2.0 (1.6)———

Week 165

1.5 (1.9)

—

—

—

—

—

–1.04

–2.349 to 0.262.08

Assessment

7

9.6 (2.8)———

Week 17

8.0 (4.0)———

Week 86

7.8 (7.7)———

Week 165

4.6 (3.4)

—

—

—

—

—

–1.08

–2.069 to –0.087.07

Assessment

7

21.4 (4.1)

—

—

—

Week 17

17.0 (3.9)

—

—

—

Week 86

13.5 (4.6)

—

—

—

Week 165

12.0 (6.6)

—

—

—

—

—

0.40

0.096 to 0.708.42

Assessment

7

23.5 (6.8)

—

—

—

Week 17

22.8 (6.0)

—

—

—

Week 86

22.4 (6.2)

—

—

—

EDE-QaGlobal score

Eating concern subscale

Shape concern subscale

Weight concern subscale

BITEc
Severity

Symptoms

BMI

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Test name and assessment time pointnMean (SD)

Cohen d (n=5)

95% CI

P value5

23.1 (6.9)

—

—

—

—

—

–0.35

–1.278 to 0.576.48

Assessment

7

14.0 (6.5)

—

—

—

Week 17

9.3 (3.8)———

Week 86

8.2 (2.7)———

Week 165

8.4 (4.8)

—

—

—

—

—

–0.52

–1.586 to 0.550.31

Assessment

7

11.1 (5.7)

—

—

—

Week 17

7.6 (5.1)———

Week 86

8.3 (5.6)———

Week 1655.8 (1.5)

—

—

—

—

—

0.46

–0.660 to 1.577.36

Assessment7

0.7 (0.1)———

Week 17

0.7 (0.2)———

Week 86

0.8 (0.2)———

Week 165

0.7 (0.1)

—

—

—

—

—

0.13

–0.852 to 1.118.78

Assessment

7

—

—

—

—

Week 17

65.6 (8.4)

—

—

—

Week 8

6

63.7 (10.5)

—

—

—

Week 165

66.0 (4.4)

—

—

—

Motivational ruler

—

—

0.00

–0.684 to 0.684>.99

Assessment

7

15.4 (3.6)

—

—

—

Week 1

7

16.4 (3.5)

—

—

—

Week 86

18.3 (1.9)

—

—

—

Week 165

16.0 (2.7)

—

—

—

Week 16
PHQ-9dGAD-7e

EQ-5Df

WAI-SFga

Hamatani et al

EDE-Q: Eating Disorder Examination Questionnaire.

b

Not applicable.

c

BITE: Bulimic Investigatory Test, Edinburgh.

dPHQ-9: 9-item Patient Health Questionnaire.

e

GAD-7: 7-item Generalized Anxiety Disorder scale.

f

EQ-5D: EurolQol–5 Dimension.

g

WAI-SF: Working Alliance Inventory-Short Form.

Discussion
Principal Findings
This study examined the feasibility of videoconference-delivered
CBT in patients with bulimia nervosa and binge-eating disorder.
Interventions based on CBT for bulimia nervosa andbinge-eating disorder were conducted, and symptom
improvement and acceptance by patients were determined before
and after the intervention. Our results suggest that ICBT via
videoconference for treating bulimia nervosa and binge-eating
disorder is feasible. This is the second study in to conduct ICBTvia videoconference that we know of and the first to apply this
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treatment strategy in Japanese patients with bulimia nervosaand binge-eating disorder. Five out of 7 participants completed
treatment, for a completion rate of 71%. The mean combined
objective binge and purging episodes and mean frequency ofobjective binge episodes and purging episodes on the EDE 16D
for the primary outcome decreased: combined objective bingeand purging episodes were reduced from 47.0 to 13.6 (71%
reduction) with a moderate Cohen d of –0.76, objective binge
episodes were reduced from 23.6 to 6.8 (71% reduction) witha large Cohen d of –0.82, and purging episodes were reduced
from 23.4 to 6.8 (71% reduction) with a moderate Cohen d of
–0.70, but no change was statistically significant. The abstinence
rate was 43% (3/7). There were no significant treatment-related
JMIR Form Res 2019 | vol. 3 | iss. 4 | e15738 | p. 9
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JMIR FORMATIVE RESEARCH
changes in any of the secondary outcomes. No adverse eventswere reported. Hence, our findings revealed that ICBT via
videoconference for patients with bulimia nervosa andbinge-eating disorder is feasible.

Comparison With Previous WorkThe results of this research are consistent with a previous RCT
in the United States that used ICBT via videoconference andreported reductions in combined objective binge and purging
episodes, objective binge episodes, and purging episodes (69%,68%, and 70%, respectively) [18]. Our previous study with
face-to-face CBT reported reduced combined objective bingeand purging episodes, objective binge episodes, and purging
episodes (51%, 50%, and 52%, respectively) [8]. This study
has resulted in changes similar to our previous study.
Furthermore, of the 5 people who completed treatment in thisstudy, the abstinence rate was 60%. The abstinence rate among
completers of ICBT via videoconference for bulimia nervosaand EDNOS was 37% [18]; the abstinence rate among
face-to-face CBT for bulimia nervosa in our previous study was
40% [8]. Our results are better than previous studies about
abstinence rate. Although previous studies did not report on
effect size of combined objective binge and purging episodes[14,18], ICBT via videoconference had a moderate Cohen d of
–0.66 for binging and a large Cohen d of –0.92 for purging at
posttreatment, in our calculation [18]. According to a systematic
review of ICBT, the range of Hedges effect sizes ranged from0.75 to 1.05 for binge episodes and from 0.41 to 0.77 for purging
episodes [14], which is similar to our findings. Furthermore,
the results of our findings are similar to those of our previous
study on CBT as a self-help strategy in Japanese patients withbulimia nervosa, in which the effect size of Cohen d for
objective binge days (EDE 16D) was large, at 0.88, and forpurging days was medium, at 0.67 [8]. Therefore, we believethat ICBT via videoconference is also feasible for Japanesepatients with an eating disorder such as bulimia nervosa or
binge-eating disorder.
First, for eating concern, a subscale of the EDE-Q, the effectsize was large, although no significant difference was found inany of the secondary outcomes. Similar large effect sizes wereobserved for BITE severity and symptoms, which have beenreported in previous studies [9,22]. Further, the BITE severity
score (mean 4.6 [SD 3.4]) and symptoms score (mean 12.0 [SD6.6]) were below the cutoff points of 5 and 20, respectively.
The eating concern subscale assesses preoccupation with food,eating, or calories; fear of losing control over eating; eating insecret; social eating; and guilt about eating [26]. BITE, whichis also related to the symptoms of overeating, had a similarly
large effect size. Therefore, ICBT via videoconference may bepromising for the treatment of overeating behavior andsymptoms in patients with an eating disorder. However, there
were no significant reductions in the restraint, shape concern,and weight concern subscales of the EDE-Q after treatment,
and the effect size of Cohen d was small. A previous RCT in
the United States using ICBT via videoconference reported alarge effect size of Cohen d for these subscales of EDE-Q, in
our calculation [18]. Similarly, our previous study on CBT asa self-help strategy in Japanese patients with bulimia nervosa
reported a large effect size of Cohen d for these subscales of
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Hamatani et al
EDE-Q [8]. The effect of ICBT via videoconference on restraint,
shape concern, and weight concern subscales of the EDE-Q
may be relatively small in comparison with previous studies.
Hence, there was no effect on dissatisfaction with body shape,
aspiration for weight loss, or cognition to suppress food intake.
Second, the PHQ-9, which was used to evaluate symptoms ofdepression, had a small effect size, while the GAD-7, which
was used to evaluate symptoms of anxiety, had a medium effectsize. The mean GAD-7 score after treatment was below thecutoff value and decreased to a mild level. However, in ourprevious study of face-to-face CBT using the same treatment
protocol, the effect sizes for PHQ-9 and GAD-7 were large [8].
The effect of ICBT via videoconference on symptoms ofdepression and anxiety associated with bulimia nervosa andbinge-eating disorder may be relatively small in comparison
with face-to-face CBT.
Third, the WAI-SF score in the range of 65.60 to 66.00 between
pretreatment and posttreatment indicates that the patient’s
relationship with the therapist was at a consistently high level
during the intervention. In a previous study in the United Statesthat analyzed WAI scores in patients with bulimia nervosa or
EDNOS who received ICBT via videoconference, there was no
significant difference in WAI scores between those who received
face-to-face CBT and those who received ICBT via
videoconference; the WAI scores for ICBT via videoconferenceindicated that this treatment was also highly rated [40].
Furthermore, motivation ruler scores were also consistently
high (16.4 to 16.0) during the intervention. This is consistent
with the result of cognitive remediation therapy for anorexia
nervosa (motivation ruler scores 14.3 to 16.1) [41]. Even if thetherapist and patient did not participate in a session in the sameroom, it was possible to maintain an adequately high level ofmotivation and a satisfactory therapeutic alliance via
videoconference. We confirmed for the first time that therapeutic
alliance between the patient and therapist via videoconference
can be sufficiently developed among Japanese patients withbulimia nervosa and binge-eating disorder. Hence, it is feasible
to use ICBT via videoconference for patients with eating
disorder who live in remote areas without them physically
visiting a hospital.
Finally, the dropout rate was 29% (2/7) in this study. An RCTof ICBT via videoconference for patients with bulimia nervosaand EDNOS reported a dropout rate of 34% (21/64) [18]. A
poor treatment alliance and complications arising from comorbid
mental illness such as depression may affect the dropout rateor treatment response [42,43]. The motivation score in patients
who dropped out was relatively high (participant 6 had a scoreof 15 out of 20; participant 7 had a score of 20 out of 20),
suggesting that motivation is not a reason for discontinuing
CBT. According to previous research, the likelihood of
discontinuation increases in subjects with less education, morenovelty-seeking behavior, previous experience with CBT, anda mismatch between the preferred treatment and that assigned[44]. According to a meta-analysis of dropout rates in studies
that included face-to-face CBT in patients with eating disorders,the diagnostic entity, definition of dropout, symptom severity
at baseline, quality of the study, and patient age had no effecton the likelihood of discontinuation of CBT; the estimated
JMIR Form Res 2019 | vol. 3 | iss. 4 | e15738 | p. 10(page number not for citation purposes)

JMIR FORMATIVE RESEARCH
overall dropout rate was 24% [45], which is similar to the study
we are reporting. In our previous face-to-face CBT study, thetreatment dropout rate was very low at 8% (2/25) [8]. It isinteresting to note that despite the ICBT via videoconference
being conducted from the same treatment manual, the study weare reporting now had a dropout rate of 29%. Although thisappears to be a factor in ICBT, our previous study of patients
receiving ICBT via videoconference for anxiety andobsessive-compulsive disorder reported a dropout rate of only
3% (1/30) [46], suggesting that the likelihood of discontinuation
may be disease-specific rather than treatment-related. The
dropout rate in patients receiving ICBT via videoconference foran eating disorder may be higher than that in their counterparts
receiving face-to-face CBT. The patients who dropped out of
this study (one with bulimia nervosa and one with binge-eating
disorder) had comorbidities that required treatment with oral
psychotropic medication in both cases. One patient had
schizophrenia, dysthymia, and social anxiety disorder, and theother had posttraumatic stress disorder and generalized anxiety
disorder. Eating disorders are often combined with significant
impairment of social function and other psychiatric disorders
including depression, anxiety, obsessive-compulsive disorder,and substance abuse disorder [47-49]. The distribution of suchcomplications in the patients in this study can be considered
representative of patients with eating disorders.
No adverse events were reported, suggesting that ICBT via
videoconference is safe for patients with bulimia nervosa, as
per a previous study [18]. Therefore, ICBT via video conference
can be safely performed in Japanese patients with bulimia
nervosa and binge-eating disorder.

Hamatani et al

Limitations
There are some limitations in this study. The first is the small
sample size, which meant that we could not determine whether
our findings are due to a type II (β) error. G-power analysis wasused to calculate the effect size, as described previously [9],which estimated the requirement of 15 samples. The second
limitation is that the study was designed as a single-arm trial
with no control group. To obtain statistically robust results, aclinical RCT is required that will estimate the sample size fromthe effect size of this study and will investigate the effectivenessof ICBT via videoconference to treat patients with bulimia
nervosa and binge-eating disorder. We are presently planningsuch a trial in patients with eating disorders in Japan[UMIN000036825].

Conclusions
Our results suggest that ICBT via videoconference for treating
bulimia nervosa and binge-eating disorder is feasible. To ourknowledge, this study is the world’s second clinical study of
ICBT via videoconference and is the first to apply this treatment
strategy in Japanese patients with bulimia nervosa andbinge-eating disorder. The frequency of objective binge andpurging episodes on the EDE 16D was reduced after treatment(71%). Hence, ICBT via videoconference has the potential tobe an effective treatment in Japanese patients with bulimia
nervosa and binge-eating disorder. The lack of any adverse
events suggests that ICBT via videoconference is safe forbulimia nervosa and binge-eating disorder. RCTs are now
needed to examine the effectiveness of this treatment strategy.

Acknowledgments
We are very grateful for the support of our research nurses, Hiroe Ota and Yohko Suwabe. We also thank Dr Hideki Hanaoka,
Mr Takumi Nakada, Ms Makiko Matsui, Ms Mayumi Ogawa, Ms Atsumi Yamazaki, and the staff at the Clinical Research Centerof Chiba University Hospital for ensuring adherence to the research plan. This research was supported by the staff of the Departmentof Psychiatry, Chiba University Hospital. The authors express their sincere appreciation to everyone involved, in particular the
study participants, for their cooperation. This work was supported by the Japan Society for the Promotion of Science Grants-in-Aid
for Scientific Research (grant numbers 18K17313 and 19J00227) and Brain/MINDS Beyond program from the Japan Agency
for Medical Research and Development (grant number 19dm0307104). The funding source had no role in the design or conductof the study.

Authors' Contributions
SH designed the study and drafted the manuscript. NN developed the manual for bulimia nervosa, conducted the cognitive
behavioral therapy, and managed the study. KM built the remote intervention system in our institution, created the digitalquestionnaire, and developed the manuscript. CS built and maintained the internet environment in our institution. HI, KO, andMT conducted the cognitive behavioral therapy. RS developed the manual for bulimia nervosa. YK analyzed the data. YH reviewed
the manuscript. ES supervised the study. All authors read and approved the final manuscript.

Conflicts of Interest
None declared.

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Abbreviations
BITE: Bulimic Investigatory Test, Edinburgh
CBT: cognitive behavioral therapy
CONSORT-EHEALTH: Consolidated Standards of Reporting Trials of Electronic and Mobile Health Applications
and Online TeleHealth
DSM-5: Diagnostic and Statistical Manual of Mental Disorders, 5th Edition
EDE 16D: Eating Disorder Examination Edition 16.0D
EDE-Q: Eating Disorders Examination Questionnaire
EDNOS: eating disorders not otherwise specified
EQ-5D-5L: EuroQol–5 Dimensions
GAD-7: 7-item Generalized Anxiety Disorder scale
ICBT: internet-based cognitive behavioral therapy
PHQ-9: 9-item Patient Heallth Questionnaire
RCT: randomized controlled trials
WAI-SF: Working Alliance Inventory–Short Form

Edited by G Eysenbach; submitted 12.08.19; peer-reviewed by S Smith, K Mathiasen, H Wang; comments to author 02.09.19; revised
version received 18.09.19; accepted 01.10.19; published 23.10.19
Please cite as:
Hamatani S, Numata N, Matsumoto K, Sutoh C, Ibuki H, Oshiro K, Tanaka M, Setsu R, Kawasaki Y, Hirano Y, Shimizu E
Internet-Based Cognitive Behavioral Therapy via Videoconference for Patients With Bulimia Nervosa and Binge-Eating Disorder:
Pilot Prospective Single-Arm Feasibility Trial
JMIR Form Res 2019;3(4):e15738
URL: http://formative.jmir.org/2019/4/e15738/
doi: 10.2196/15738
PMID: 31647472©Sayo Hamatani, Noriko Numata, Kazuki Matsumoto, Chihiro Sutoh, Hanae Ibuki, Keiko Oshiro, Mari Tanaka, Rikukage Setsu,
Yohei Kawasaki, Yoshiyuki Hirano, Eiji Shimizu. Originally published in JMIR Formative Research (http://formative.jmir.org),
23.10.2019. This is an open-access article distributed under the terms of the Creative Commons Attribution License(https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium,provided the original work, first published in JMIR Formative Research, is properly cited. The complete bibliographic information,a link to the original publication on http://formative.jmir.org, as well as this copyright and license information must be included.

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