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Effectiveness of acceptance and commitment therapy for irritable bowel syndrome non-patients: A pilot randomized waiting list controlled trial
Journal of Contextual Behavioral Science 15 (2020) 85–91
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Effectiveness of acceptance and commitment therapy for irritable bowel syndrome non-patients: A pilot randomized waiting list controlled trial
T
Masataka Itoa,∗, Takashi Mutob a b
Graduate School of Psychology, Doshisha University, 1–3 Tatara-Miyakodani, Kyotanabe, Kyoto, Japan Faculty of Psychology, Doshisha University, 1–3 Tatara-Miyakodani, Kyotanabe, Kyoto, Japan
A R T I C LE I N FO
A B S T R A C T
Keywords: Irritable bowel syndrome Acceptance and commitment therapy Non-patients One day session Randomized controlled trial
Irritable bowel syndrome (IBS) is one of the most common functional disorders, and an intervention targeting IBS non-patients (with symptoms and undiagnosed) is needed. This study examined the efficacy of acceptance and commitment therapy (ACT) in IBS non-patients. A total of 26 non-patients were randomly assigned to either an intervention group (n = 14) or a waiting list group (n = 12). Self-reported IBS symptom severity, quality of life, psychological distress (anxiety and depression), and psychological flexibility were assessed at three time points. The intervention group completed an ACT program consisting of a one-day group session and a twomonth self-help program. This program reduced depressive mood but not symptom severity. These results suggest that this ACT program is insufficient for IBS non-patients and the intervention needs further modification.
1. Introduction Irritable bowel syndrome (IBS) is a highly prevalent disorder, with about 11% of the adult population affected in most countries (Lovell & Ford, 2012). This disease is characterized by abdominal pain, abdominal distention, and changes in bowel habits, and it severely affects quality of life (QOL; Longstreth et al., 2006). IBS is associated with psychological factors like stress and anxiety (Spiller et al., 2007). The social impact of this disease is also notable. Although IBS is not a cause of mortality, the monetary and productivity costs relating to IBS treatment tend to be very high (Inadomi, Fennerty, & Bjorkman, 2003). Several psychological treatments for IBS have been investigated. Among these, strong evidence has emerged for the efficacy of cognitive behavioral therapy (CBT; Zijdenbos, de Wit, van der Heijden, Rubin, & Quartero, 2009). Studies have found that effective forms of CBT exert their symptom reduction and QOL improvements by means of a reduction in visceral anxiety (Labus, Mayer, Chang, Bolus, & Naliboff, 2007). However, there are many people with IBS symptoms who do not have an IBS diagnosis; these individuals are referred to as IBS non-patients. Cañón, Ruiz, Rondón, and Alvarado (2017) reported that the prevalence of IBS symptoms among university students and staff is 24%. Although non-patients exhibit less visceral anxiety than do patients (Labus et al., 2007), they exhibit higher levels of anxiety than do people with no IBS symptoms (Hazlett-Stevens, Craske, Mayer, Chang, ∗
& Naliboff, 2003). Therefore, the QOL in IBS non-patients also seems to suffer (Frank et al., 2002). There are currently no studies investigating which psychological interventions are effective for IBS non-patients. In a meta-analysis of psychological treatments for IBS patients (Zijdenbos et al., 2009), 84% of studies investigated treatments implemented as part of secondary or tertiary care, and the remainder investigated those implemented as part of primary care. Although treatment for IBS non-patients is needed because about 30% of IBS non-patients become IBS patients within three years (Fujii & Nomura, 2008), many psychological treatments for IBS only target patients with severe symptoms. Among the various forms of CBT, we propose that ACT can function as an intervention for IBS non-patients for three reasons. First, previous studies have shown that ACT for IBS patients is effective in reducing the severity of symptoms and improving QOL (Ferreira, Gillanders, Morris, & Eugenicos, 2017; Gillanders, Ferreira, Angioni, Carvalho, & Eugenicos, 2017). Second, there is evidence suggesting that ACT is effective for subclinical cases. For example, ACT was shown to improve general mental health and reduce overall distress in non-patient college students who were at risk of mental illness (Muto, Hayes, & Jeffcoat, 2011). Third, the treatment mechanism of ACT is appropriate for IBS non-patients’ characteristics. ACT aims to increase psychological flexibility, which comprises acceptance, defusion, contact with the present moment, self-as-context, values, and committed action, and to facilitate behavior that accords with one's personal values (Hayes, Strosahl, &
Corresponding author. Graduate School of Psychology, Doshisha University, 1–3 Tatara-Miyakodani, Kyotanabe, Kyoto, 610-0394, Japan. E-mail addresses: [email protected] (M. Ito), [email protected] (T. Muto).
https://doi.org/10.1016/j.jcbs.2019.11.009 Received 28 March 2019; Received in revised form 25 September 2019; Accepted 27 November 2019 2212-1447/ © 2019 The Authors. Published by Elsevier Inc. on behalf of Association for Contextual Behavioral Science. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/).
Journal of Contextual Behavioral Science 15 (2020) 85–91
M. Ito and T. Muto
Hsiao, & Kurokawa, 1998). We used three summary scores (Suzukamo et al., 2011): the physical component summary (PCS), the mental component summary (MCS), and the role/social component summary (RCS). Higher scores represent better QOL. Good internal consistency was shown for PCS (Cronbach's α = 0.81-0.86), RCS (Cronbach's α = 0.79-0.89), and MCS (Cronbach's α = 0.88-0.90).
Wilson, 2012). In IBS patients, the improvement of psychological flexibility leads to better QOL (Ferreira et al., 2017). These studies suggest that ACT may be effective for IBS non-patients in reducing the severity of symptoms and improving QOL. The current study aimed to examine the effectiveness of ACT for IBS non-patients. If this intervention is effective for non-patients, we may expect to see improvements in symptom severity, QOL, and psychological distress, along with changes in participants’ psychological flexibility.
2.3.3. Beck Depression Inventory-II (BDI-II) The BDI-II was used to measure depression (Beck, Steer, & Brown, 1996), with higher scores representing more depressive symptoms. The Japanese version of the BDI-II is well-validated (Kojima et al., 2002). In this study, BDI-II showed good internal consistency (Cronbach's α = 0.91-0.94).
2. Materials and methods 2.1. Participants
2.3.4. State-Trait Anxiety Inventory (STAI) The STAI was used to measure state anxiety (STAI-S) and trait anxiety (STAI-T) (Spielberger, Gorsuch, & Lushene, 1983), with higher scores indicating more anxiety. The Japanese version of the STAI has been validated in previous studies (Hidano, Fukuhara, Iwawaki, Soga, & Spielberger, 2000). Good internal consistency was shown for the STAI-S (Cronbach's α = 0.92-0.94), and STAI-T (Cronbach's α = 0.87- 0.92).
Participants were recruited from a university population by means of a screening survey. The screening survey used the Japanese version of the irritable bowel syndrome severity index (IBSSI; Shinozaki et al., 2006). A total of 329 undergraduate students participated in the screening survey. Those who scored above the clinical cut-off score on the IBSSI at screening (200 people) were invited to participate in the study, with 169 declining to do so. Of the remaining 31, five participants recovered to the extent that they scored below the clinical cut-off on the IBSSI at a pre-intervention assessment, and thus were excluded from the study. The remaining 26 participated in this study, and their mean age was 19.9 years (SD = 1.23). Further, the majority of participants were female (61.5%). There were four exclusion criteria: (1) undergoing psychopharmacological or psychological treatment for gastrointestinal or psychiatric disorders; (2) the presence of warning symptoms which suggested the presence of organic disease at the selfreported screening and assessment (e.g., anemia, inflammatory reactions, fecal occult blood, unexplained weight loss in the past six months, or a family history of colon cancer); (3) suicidal ideation; and (4) individuals whom the investigator determined to be unsuitable as participants (e.g., unable to communicate effectively in Japanese).
2.4. Process measures 2.4.1. Acceptance and Action Questionnaire-II (AAQ-II) The AAQ-II was used to assess experiential avoidance, which is the key process targeted in ACT, with higher scores indicating more frequent avoidance. The AAQ-II has been found to have adequate reliability and validity (Bond et al., 2011) and has been translated into Japanese (Shima, Yanagihara, Kawai, & Kumano, 2013). The AAQ had good internal consistency (Cronbach's α = 0.82-0.91). 2.4.2. Cognitive Fusion Questionnaire (CFQ) The CFQ is a 13-item measure of cognitive fusion, which is a component of psychological flexibility, with higher scores indicating more cognitive fusion. This scale has been shown to have good psychometric properties (Gillanders et al., 2014), and the Japanese version has shown similar psychometric properties (Shima, Yanagihara, Kawai, & Kumano, 2014). In the current study, the CFQ had acceptable internal consistency (Cronbach's α = 0.73-0.90).
2.2. Primary outcome measure 2.2.1. Japanese version of the IBS Severity Index (IBSSI) The IBSSI (Francis, Morris, & Whorwell, 1997) was developed to assess the major symptoms of IBS, and it has been translated into Japanese (Shinozaki et al., 2006). This measure consists of 7 items relating to the severity and duration of abdominal pain, severity of abdominal distention, dissatisfaction with bowel habits, and interference in their life, with higher values representing higher levels of severity. Both the original and Japanese versions of IBSSI have pre-determined cut-off scores which indicate mild (75–174), moderate (175–299), or severe (300–500) IBS. The Japanese version of the IBSSI showed acceptable internal consistency (Cronbach's α = 0.69) and test-retest reliability (ICC = 0.86; Shinozaki et al., 2006). However, in the current study, the IBSSI demonstrated lower internal consistency (α = 0.34–0.67) across the assessments.
2.4.3. Five Facet Mindfulness Questionnaire (FFMQ) The FFMQ (Baer et al., 2008) was used to measure five dimensions of mindfulness, with higher scores indicating greater mindfulness. The Japanese version of this questionnaire has been validated (Sugiura, Sato, Ito, & Murakami, 2012). In this study, the FFMQ showed acceptable internal consistency (Cronbach's α = 0.56-0.69). 2.5. Adherence quizzes Adherence multiple-choice quizzes were administered online on six occasions to measure the participants’ use of the workbook. Each quiz consisted of 10 items that were relevant to two or three chapters of the book. Quizzes examined participants understanding of book content (e.g., “In ACT, what part of the issue are you focusing on?“).
2.3. Secondary outcome measures 2.3.1. Japanese version of the IBS-QOL The IBS-QOL instrument (Patrick, Drossman, Frederick, Dicesare, & Puder, 1998) was developed to assess symptom-related QOL, and has been translated into Japanese (Kanazawa et al., 2007), with higher scores indicating a better QOL. Internal consistency was almost identical (Cronbach's α = 0.96 - 0.97) across assessments in the present study.
2.6. Treatment protocol The procedure used in this study followed a treatment protocol used by Ferreira et al. (2017) and published by the Association for Contextual Behavioral Science (Ferreira & Gillanders, 2012a). This protocol consists of two main elements: (1) a one-day group ACT workshop, and (2) a two-month period of self-help using a workbook. The initial workshop did not have any notable changes from the protocol, except that only one facilitator was used (see supplementary material). The first author, who is a licensed clinical psychologist, administered all
2.3.2. Short Form (36) Health Survey (SF-36) The SF-36, developed based on the Medical Outcome Study, is a 36item measure assessing health-related QOL (Ware, Kosinski, & Keller, 1994) and has been translated into Japanese (Fukuhara, Bito, Green, 86
Journal of Contextual Behavioral Science 15 (2020) 85–91
M. Ito and T. Muto
Fig. 1. Flow chart showing participants' paths through the trial.
this, a post-intervention assessment was administered. Finally, a followup assessment was administered two months after the end of the selfhelp period. At the end of the workshop, participants received a 6000yen (about $57) book token in return for their participation. The waiting list group was offered the same intervention after the follow-up assessment. The study was approved by the research ethics committees of the authors’ affiliated university and registered with the clinical trial registry (UMIN CTR: UMIN000027728).
workshops as the facilitator. At the end of the workshop, all participants were provided with an ACT workbook (Japanese version of Get Out of Your Mind and Into Your Life (Hayes & Smith, 2010)) that aimed to allow them to maintain the workshop content. Previous studies of ACT for IBS patients (Ferreira et al., 2017; Gillanders et al., 2017) have used the workbook Better Living with IBS (Ferreira & Gillanders, 2012b). We changed the workbook because targeting general suffering may be more appropriate for IBS non-patients, who have less severe symptoms than IBS patients, and because a Japanese translation of Better Living with IBS was not available. Moreover, the workbook has been previously shown to be effective with Japanese college students (Muto et al., 2011).
2.8. Data analysis All data analyses were conducted using IBM SPSS Statistics, version 25.0. A last-observation-carried-forward imputation method was used for missing data. For the outcome analysis, we conducted a 2 × 3 mixed-design analysis of variance (ANOVA) on each outcome variable, with group (intervention or waiting list) as a between-person factor and time (pre-intervention, post-intervention, and two-month follow-up) as a within-person factor. In the case of a significant group × time interaction, we investigated the simple main effects using multiple comparisons with the Bonferroni correction procedure. To evaluate clinical significance, we calculated the Reliable Change Index and threshold for clinically significant change for each outcome measure (Jacobson & Truax, 1991). These calculations used values from the validation study of the corresponding instrument.
2.7. Procedure Fig. 1 provides a flow chart representing participants' paths through this experiment. Participants who scored above the cut-off score on the IBSSI were invited by email to participate following the screening survey. The nature and purpose of the study was explained to each potential participant individually, and 31 participants provided informed consent to participate. A pre-intervention assessment was administered one week before the ACT workshop. Ultimately, 26 participants were randomly assigned to an intervention group (n = 14) or a waiting list group (n = 12) using sequentially numbered, opaque, sealed envelope randomization, which was implemented using a computer-generated list (www.random.org.). The intervention group completed the ACT workshop and the self-help program with the workbook over the course of two months. Participants completed six adherence quizzes at intervals of 10 days during the self-help period. Following 87
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Note; p relates to Fisher's exact test; WL = Waiting List; IBSSI = Irritable Bowel Syndrome Severity Index; IBSQOL = Irritable Bowel Syndrome-Quality of Life measure; SF-36 = MOS 36-Item Short-Form Health Survey; PCS = Physical Component Summary; MCS = Mental component Summary; RCS = Role/social Component Summary; BDI = Beck Depression Inventory-II; STAI-S = State-Trait Anxiety Inventory-State; STAI-T = StateTrait Anxiety Inventory-Trait; AAQ = Acceptance and Action Questionnaire-II; CFQ = Cognitive Fusion Questionnaire; FFMQ = Five Facet Mindfulness Questionnaire.
0.91 0.49 0.14 0.50 0.46 0.25 1.21 1.23 1.71 0.48 0.43 0.08 1.3 0.33 1.72 1.44 1.08 1.76 (10.30) (11.52) (9.18) (14.31) (8.56) (4.64) (5.17) (4.94) (2.60) 57.37 38.51 35.37 21.00 49.25 60.00 31.75 56.50 104.50 (2.68) (13.94) (8.20) (11.26) (11.50) (10.09) (13.43) (10.09) (9.18) 56.51 42.98 46.27 15.40 45.20 53.40 23.60 53.80 111.40 (8.12) (7.46) (15.04) (9.58) (10.85) (8.76) (8.56) (10.60) (11.16) 59.16 40.37 42.02 14.14 47.71 54.36 21.57 50.21 116.29
60.62 38.91 39.65 13.44 49.11 54.89 20.44 48.22 111.4
(5.61) (11.17) (13.30) (9.18) (10.91) (8.54) (5.00) (10.92) (11.71)
(1.30) (43.58) (13.92) 19.8 175 85.59 (1.36) (57.79) (14.10) 19.86 194.07 86.13
Age IBSSI IBS-QOL SF-36 PCS MCS RCS BDI-II STAI-S STAI-T AAQ-II CFQ FFMQ
19.89 204.67 86.43 (1.21) (53.46) (13.50)
64.29 Gender (% Female)
66.67
58.11 38.39 44.83 18.38 49.13 59.88 23.75 52.88 111.63 (5.80) (6.25) (14.55) (10.45) (11.60) (7.51) (8.61) (6.93) (8.79) 57.867 38.428 41.68 19.25 49.17 59.92 26.42 54.08 109.25
(8.37) (11.59) (11.08) (9.01) (9.26) (7.20) (6.80) (5.26) (9.52)
(1.50) (115.79) (30.91) 20.75 258.75 67.28 19.63 182.50 78.86 (1.04) (102.01) (23.16) 20.08 207.92 75.00
(0.92) (91.61) (19.55)
50.00 62.50 58.33 60.00
Completer n = 8 Mean (SD) over all n = 12 Mean (SD) over all n = 14 Mean (SD)
Intervention variable
Table 1 Baseline demographics.
Completer n = 9 Mean (SD)
lost to follow up n = 5 Mean (SD)
Wait list
lost to follow up n = 4 Mean (SD)
p .54 t (24) 0.29 0.44 1.53
Intervention vs waiting list
p 0.61 t (24) 0.90 0.55 0.68
completer vs lost to follow up
M. Ito and T. Muto
3. Results 3.1. Preliminary analyses Table 1 shows the results of independent t-tests and Fisher's exact tests at baseline. There was no significant difference between the groups in their characteristics and pre-intervention assessment scores on any measures. Five intervention group participants and four waiting list group participants missed at least one assessment. There was no significant difference between those who completed all assessments and those who did not on their characteristics and measures. Finally, a Fisher's exact test showed that there was no difference in attrition rate between the groups (p = .61). 3.2. Outcome results Table 2 shows the means, standard deviations, results of ANOVA, and effect sizes for the changes between each time point on all outcome measures at pre-intervention assessment, post-intervention assessment, and two-month follow-up. Primary outcomes did not show significant changes. Secondary outcomes showed a significant interaction only on BDI-II. On this measure, the intervention group's scores significantly improved and the waiting list group's scores worsened. Process measures did not show significant interactions. 3.3. Reliable change and clinical significance Table 3 displays the reliable change index, cut-off score for clinical significance, and average change score for participants in each group who completed the relevant assessments for each outcome measure. On an individual level, 40% of participants in the intervention group showed signs of recovery from IBS symptoms (i.e., reliable and clinically significant change on the IBSSI) during the post-intervention assessment, and 20% showed signs of recovery during the follow-up assessment. No participants in the waiting list group showed signs of recovery from IBS symptoms on reliable change scores. Some participants demonstrated signs of recovery at the post-intervention and follow-up assessments on the BDI-II, STAI-S, and STAI-T. 3.4. Treatment compliance Participants in the intervention group completed an average of 2.9 of the 6 adherence quizzes (47.6%). The accuracy rate for their answers was 35.0% (21/60 questions). Outcome measures showed no significant association with compliance measures. 4. Discussion The aim of this study was to evaluate the efficacy of a one-day group ACT program for IBS non-patients. This program led to a significant improvement in depressive mood compared to the waiting list group. In addition, findings with the IBSSI indicated that 40% of participants in the intervention group showed clinically reliable signs of recovery postintervention compared to none of the participants in the control group. These changes that occurred following an ACT program are encouraging for the potential use of this intervention with IBS non-patients. Although the current findings do not support that an ACT intervention may improve the severity of IBS symptoms in IBS non-patients, the IBSSI had some limitations. As this measure showed lower internal consistency, there might be a problem with the reliability of the current results. Moreover, these outcomes showed lower statistical power (1beta = 0.70; alpha = .05, ηp2 = 0.04). These results make conclusions regarding the effect of the intervention on IBS symptoms difficult. This study demonstrated that the ACT program led to some improvement in depressive mood in IBS non-patients, which is consistent with previous studies of ACT (A-Tjak et al., 2015). A meta-analysis 88
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M. Ito and T. Muto
Table 2 All Variables at Pre-intervention, Post-intervention, and 2-Month Follow-up Assessments, ANOVA analysis, and effect sizes. Variable
IBSSI IBS-QOL SF-36 PCS MCS RCS BDI-II STAI-S STAI-T AAQ-II CFQ FFMQ
Mean (SD)a Pre-intervention
Group
Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list
194.07 207.92 86.134 75
Post-intervention
(53.46) (102.01) (13.50) (23.16)
59.156 (8.12) 57.867 (5.80) 40.365 (7.46) 38.428 (6.25) 42.021 (15.04) 41.68 (14.55) 14.14 (9.58) 19.25 (10.45) 47.71 (10.85) 49.17 (11.60) 54.36 (8.76) 59.92 (7.51) 21.57 (8.56) 26.42 (8.61) 50.21 (10.60) 54.08 (6.93) 116.29 (11.16) 109.25 (8.79)
2-month follow-up
group effect F (1,24)
time effect F (2,48)
group*time interaction F (2,48)
Effect (ηp2)
130.00 187.5 84.78 75.07
(89.91) (95.55) (16.64) (17.32)
128.33 174.12 88.24 79.78
(67.92) (75.06) (14.42) (13.86)
1.96
4.45
1.01
.04
2.38
1.02
0.39
.02
62.01 60.03 40.92 39.72 37.51 38.75 13.40 25.70 48.60 53.00 54.50 59.50 23.10 28.50 51.70 52.60 119.20 106.60
(6.50) (9.77) (6.71) (12.06) (11.80) (8.27) (9.97) (12.34) (9.56) (11.03) (10.08) (8.96) (7.74) (6.49) (11.06) (6.77) (12.63) (8.26)
58.6 57.41 47.97 45.49 43.28 38.6 8.00 22.25 43.22 50 48.33 60.63 18.33 27 41.89 49.87 125.89 111.25
(3.22) (5.99) (10.77) (10.71) (12.41) (11.20) (8.06) (13.13) (13.09) (7.78) (11.63) (20.40) (8.20) (6.89) (15.19) (5.79) (23.07) (10.96)
0.09
2.45
0.18
.01
0.6
8.33
0.37
.02
0.37
1.62
0.88
.04
5.33
2.51
10.17**
.30
1.03
1.75
1.64
.06
3.34
0.60
0.94
.04
4.30
0.95
1.67
.07
1.01
2.54
0.50
0.02
6.11
0.69
1.05
0.04
Effect size (within Cohen's d) pre post
pre - 2 month FU
0.97 0.41 0.20 0.01
1.32 0.33 0.36 0.36
0.20 0.36 0.30 0.21 0.18 0.35 0.15 1.42 0.10 0.73 0.02 0.09 0.36 0.33 0.31 0.22 0.23 0.34
0.08 0.10 0.84 0.93 0.13 0.15 1.10 0.56 0.35 0.08 0.62 0.04 0.53 0.07 0.71 0.61 0.58 0.48
Note. Effect size (within Cohen's d) defined as [(mean1−mean2)/SQRT [(SD1)2 + (SD2)2)/2)]]/SQRT (2*(1-r))]. FU = Follow-up; IBSSI = Irritable Bowel Syndrome Severity Index; IBS-QOL = Irritable Bowel Syndrome-Quality of Life measure; SF-36 = 36-item Short-Form Health Survey; PCS = Physical Component Summary; MCS = Mental Component Summary; RCS = Role/social Component Summary; BDI-II = Beck Depression Inventory-II; STAI-S = State-Trait Anxiety InventoryState; STAI-T = State-Trait Anxiety Inventory-Trait; AAQ-II = Acceptance and Action Questionnaire-II; CFQ = Cognitive Fusion Questionnaire; FFMQ = Five Facet Mindfulness Questionnaire. aRaw means, without adjustment for missing values.
better outcomes. These results suggest that the current intervention did not lead to consistent practice in daily life. Therefore, in the case of such participants, it may be necessary to modify the intervention to provide more support aimed at maintaining their practice. It should be borne in mind, however, that the participants in the present study were IBS non-patients, who may have been less motivated to engage in treatment than patients (DiMatteo, Haskard, & Williams, 2007). For example, a study using internet-delivered self-help for IBS patients found that this method of delivery provides greater accessibility (Ljótsson et al., 2010). Their intervention, which is similar to ACT, showed a positive effect on IBS symptoms, and participants actively utilized their program. These findings show that modifying the method by which self-help is offered can lead to an increase in practice in daily life and thereby a more effective intervention.
study showed that depression is associated with a twofold risk for IBS onset (Sibelli et al., 2016). Additionally, the severity of IBS symptoms was predicted by psychological distress (Phillips, Wright, & Kent, 2013). As the current intervention appears to have improved participant's depressive symptoms, this improvement may lead to preventing IBS symptoms becoming more severe. The results suggest a possibility that empowering participants to engage in the practice of ACT skills can lead to improvement in outcomes and psychological flexibility. The previous study of IBS patients (Ferreira et al., 2017) found that 82.2% of participants reported using the workbook, and these participants showed improvement in IBS severity and QOL. Another previous study (Muto et al., 2011) using adherence test showed a higher rate of completion and correct answers than those in the current study, and their higher compliance rate lead to Table 3 Reliable and Clinically Significant Change in each Group. RC
IBSSI
59.94
Cut-off score
< 81* †
IBS-QOL
11.06
> 80
BDI-II
7.82
< 12*
STAI-S
9.17
< 47*
STAI-T
11.64
< 52*
group
Int WL Int WL Int WL Int WL Int WL
Pre - Post
Pre - 2-month follow-up
Average Change
RC%
RC and CS%
Average change
RC%
RC and CS%
78.20 26.50 0.66 −3.31 2.10 −5.30 1.90 −1.60 1.70 −1.50
60.00 10.00 0.00 12.50 0.00 0.00 0.00 0.00 10.00 0.00
40.00 0.00 0.00 12.50 0.00 0.00 0.00 0.00 10.00 0.00
76.33 8.37 1.80 −0.92 5.44 −3.88 5.89 −0.88 6.56 −0.75
44.44 25.00 0.00 12.50 22.22 0.00 11.11 0.00 22.22 0.00
22.22 0.00 0.00 12.50 11.11 0.00 11.11 0.00 22.22 0.00
Note. RC = reliable change, defined as 1.96 * SQRT(2) * SQRT(1- alpha); CS = clinically significant; IBSSI = Irritable Bowel Syndrome Severity Index; IBS-QOL = Irritable Bowel Syndrome-Quality of Life measure; BDI-II = Beck Depression Inventory-II; STAI-S = State-Trait Anxiety Inventory-State; STAI-T = State-Trait Anxiety Inventory-Trait. *Cut-off score was determined by the results of a validation study (IBSSI: Francis et al., 1997; BDI-II: Kojima et al., 2002; STAI-S, STAI-T: Hidano et al., 2000). †Cut-off score was determined by suggested cut-off (Cañón et al., 2017). 89
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starting point for interventions with IBS non-patients, and future modifications of the method of the intervention may lead to improved health for IBS non-patients.
In summary, this study found that an ACT program targeting IBS non-patients was not sufficient to improve IBS symptoms. On the other hand, it could be argued that the improvement in depressive symptoms is a positive change for IBS non-patients. Although the resulting changes in depression and IBS symptoms appear encouraging, more studies are needed to investigate the levels of improvement. Encouraging interventions that lead to increased self-help may lead to greater improvement. Overall, the results of this study provide a
Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Appendix A Example questions of adherence tests Q. In ACT, what part of the issue are you focusing on? 1. Form 2. Situation Q. What does it mean to “ride your mind-train”? 1. To do something automatically and uncon2. Doubt the language sciously Q. Why are people stuck in the system of experiential avoidance? 1. Eliminating unpleasant things works well 2. Making the problem bigger Q. What does the metaphor of the “hungry tiger” mean? 1. The dangers of feeding animals 2. Avoidance is not an effective approach Q. What was the purpose of the exercise of “floating leaves in a moving stream”? 1. Letting one's thoughts wander 2. Understanding one's thoughts Q. What does chessboard mean in the chess metaphor? 1. A place with emotions 2. Thoughts and emotion Q. What is a good way to establish daily mindfulness practice? 1. Taking time 2. Enjoying Q. What are the limits of the willingness to your experience? 1. Public restrictions 2. The quality of private experience Q. While “physicalizing”, you usually 1. Feel good 2. Get tired Q. What are values? 1.Achievement 2. Direction Q. How do you check to see that you have met your goal? 1. Feel better 2. Feasibility Q. In ACT, how do you approach barriers? 1. Making a detour 2. Breaking the barrier
3. Function
4. Disorder
3. Being confident
4. Being distressed
3. Eliminating unpleasant situations
4. Coping with the problem
3. The effectiveness of avoidance
4. A tiger becomes ferocious
3. Ignoring one's thoughts
4. Distancing oneself from thoughts
3. Perceiving thoughts and emotions objectively
4. A place to think
3. Stop when you feel sick
4. Relaxing
3.The degree of private experience
4. The magnitude of anxiety
3. Feel ridiculous about doing the exercises
4. Are easy to accept
3. Objective
4. Goal
3.Engage in enjoyable activities
4. Achievements
3. Getting along the barriers
4. Getting over the barriers
Appendix B. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.jcbs.2019.11.009.
system: A simple method of monitoring irritable bowel syndrome and its progress. Alimentary Pharmacology and Therapeutics, 11, 395–402. https://doi.org/10.1046/j. 1365-2036.1997.142318000.x. Frank, L., Kleinman, L., Rentz, A., Ciesla, G., Kim, J. J., & Zacker, C. (2002). Healthrelated quality of life associated with irritable bowel syndrome: Comparison with other chronic diseases. Clinical Therapeutics, 24, 675–689. https://doi.org/10.1016/ S0149-2918(02)85143-8. Fujii, Y., & Nomura, S. (2008). A prospective study of the psychobehavioral factors responsible for a change from non-patient irritable bowel syndrome to IBS patient status. BioPsychoSocial Medicine, 2, 16. https://doi.org/10.1186/1751-0759-2-16. Fukuhara, S., Bito, S., Green, J., Hsiao, A., & Kurokawa, K. (1998). Translation, adaptation, and validation of the SF-36 Health Survey for use in Japan. Journal of Clinical Epidemiology, 51, 1037–1044. https://doi.org/10.1016/S0895-4356(98)00095-X. Gillanders, D. T., Bolderston, H., Bond, F. W., Dempster, M., Flaxman, P. E., Campbell, L., et al. (2014). The development and initial validation of the Cognitive Fusion questionnaire. Behavior Therapy, 45, 83–101. https://doi.org/10.1016/j.beth.2013.09. 001. Gillanders, D., Ferreira, N. B., Angioni, E., Carvalho, S. A., & Eugenicos, M. P. (2017). An implementation trial of ACT-based bibliotherapy for irritable bowel syndrome. Journal Contextual Behavioral Science, 6, 172–177. https://doi.org/10.1016/j.jcbs. 2017.04.006. Hayes, S. C., & Smith, S. (2010). ACT wo Hajimeru: Self-help no tameno Workbook. Tokyo: Seiwa shuppan T. Muto, H. Harai, M. Yoshioka, & M. Okajima, Trans. Hayes, S. C., Strosahl, K. D., & Wilson, K. G. (2012). Acceptance and commitment therapy: The process and practice of mindful change (2nded.). New York: Guilford Press. Hazlett-Stevens, H., Craske, M. G., Mayer, E. A., Chang, L., & Naliboff, B. D. (2003). Prevalence of irritable bowel syndrome among university students: The roles of worry, neuroticism, anxiety sensitivity and visceral anxiety. Journal of Psychosomatic Research, 55, 501–505. https://doi.org/10.1016/S0022-3999(03)00019-9. Hidano, T., Fukuhara, M., Iwawaki, S., Soga, S., & Spielberger, C. D. (2000). State–trait anxiety inventory (form JYZ) test manual. (Japanese adaptation of STAI). Tokyo:
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Jitsumu-Kyoiku Shuppan. Inadomi, J. M., Fennerty, M. B., & Bjorkman, D. (2003). The economic impact of irritable bowel syndrome. Alimentary Pharmacology and Therapeutics, 18, 671–682. https:// doi.org/10.1046/j.1365-2036.2003.t01-1-01736.x. Jacobson, N. S., & Truax, P. (1991). Clinical significance: A statistical approach to defining meaningful change in psychotherapy research. Journal Consulting and Clinical Psychologv, 59, 12–19. https://doi.org/10.1037/0022-006X.59.1.12. Kanazawa, M., Drossman, D. A., Shinozaki, M., Sagami, Y., Endo, Y., Palsson, O. S., et al. (2007). Translation and validation of a Japanese version of the irritable bowel syndrome-quality of life measure (IBS-QOL-J). BioPsychoSocial Medicine, 1, 6. https:// doi.org/10.1186/1751-0759-1-6. Kojima, M., Furukawa, T. A., Takahashi, H., Kawai, M., Nagaya, T., & Tokudome, S. (2002). Cross-cultural validation of the Beck depression inventory-II in Japan. Psychiatry Research, 110, 291–299. https://doi.org/10.1016/S0165-1781(02) 00106-3. Labus, J. S., Mayer, E. A., Chang, L., Bolus, R., & Naliboff, B. D. (2007). The central role of gastrointestinal-specific anxiety in irritable bowel syndrome: Further validation of the visceral sensitivity index. Psychosomatic Medicine, 69, 89–98. https://doi.org/10. 1097/PSY.0b013e31802e2f24. Ljótsson, B., Falk, L., Vesterlund, A. W., Hedman, E., Lindfors, P., Rück, C., et al. (2010). Internet-delivered exposure and mindfulness based therapy for ittitable bowel syndrome – a randomized control trial. Behaviour Research and Therapy, 48, 531–539. https://doi.org/10.1016/j.brat.2010.03.003. Longstreth, G. F., Thompson, W. G., Chey, W. D., Houghton, L. A., Mearin, F., & Spiller, R. C. (2006). Functional bowel disorders. Gastroenterology, 130, 1480–1491. https://doi. org/10.1053/j.gastro.2005.11.061. Lovell, R. M., & Ford, A. C. (2012). Global prevalence of and risk factors for irritable bowel syndrome: A meta-analysis. Clinical Gastroenterology and Hepatology, 10, 712–721. https://doi.org/10.1016/j.cgh.2012.02.029. Muto, T., Hayes, S. C., & Jeffcoat, T. (2011). The effectiveness of Acceptance and Commitment Therapy bibliotherapy for enhancing the psychological health of Japanese college students living abroad. Behavior Therapy, 42, 323–335. https://doi. org/10.1016/j.beth.2010.08.009. Patrick, D. L., Drossman, D. A., Frederick, I. O., Dicesare, J., & Puder, K. L. (1998). Quality of life in persons with irritable bowel syndrome (development and validation of a new measure). Digestive Diseases and Sciences, 43, 400–411. https://doi.org/10.1023/
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Effectiveness of acceptance and commitment therapy for irritable bowel syndrome non-patients: A pilot randomized waiting list controlled trial
T
Masataka Itoa,∗, Takashi Mutob a b
Graduate School of Psychology, Doshisha University, 1–3 Tatara-Miyakodani, Kyotanabe, Kyoto, Japan Faculty of Psychology, Doshisha University, 1–3 Tatara-Miyakodani, Kyotanabe, Kyoto, Japan
A R T I C LE I N FO
A B S T R A C T
Keywords: Irritable bowel syndrome Acceptance and commitment therapy Non-patients One day session Randomized controlled trial
Irritable bowel syndrome (IBS) is one of the most common functional disorders, and an intervention targeting IBS non-patients (with symptoms and undiagnosed) is needed. This study examined the efficacy of acceptance and commitment therapy (ACT) in IBS non-patients. A total of 26 non-patients were randomly assigned to either an intervention group (n = 14) or a waiting list group (n = 12). Self-reported IBS symptom severity, quality of life, psychological distress (anxiety and depression), and psychological flexibility were assessed at three time points. The intervention group completed an ACT program consisting of a one-day group session and a twomonth self-help program. This program reduced depressive mood but not symptom severity. These results suggest that this ACT program is insufficient for IBS non-patients and the intervention needs further modification.
1. Introduction Irritable bowel syndrome (IBS) is a highly prevalent disorder, with about 11% of the adult population affected in most countries (Lovell & Ford, 2012). This disease is characterized by abdominal pain, abdominal distention, and changes in bowel habits, and it severely affects quality of life (QOL; Longstreth et al., 2006). IBS is associated with psychological factors like stress and anxiety (Spiller et al., 2007). The social impact of this disease is also notable. Although IBS is not a cause of mortality, the monetary and productivity costs relating to IBS treatment tend to be very high (Inadomi, Fennerty, & Bjorkman, 2003). Several psychological treatments for IBS have been investigated. Among these, strong evidence has emerged for the efficacy of cognitive behavioral therapy (CBT; Zijdenbos, de Wit, van der Heijden, Rubin, & Quartero, 2009). Studies have found that effective forms of CBT exert their symptom reduction and QOL improvements by means of a reduction in visceral anxiety (Labus, Mayer, Chang, Bolus, & Naliboff, 2007). However, there are many people with IBS symptoms who do not have an IBS diagnosis; these individuals are referred to as IBS non-patients. Cañón, Ruiz, Rondón, and Alvarado (2017) reported that the prevalence of IBS symptoms among university students and staff is 24%. Although non-patients exhibit less visceral anxiety than do patients (Labus et al., 2007), they exhibit higher levels of anxiety than do people with no IBS symptoms (Hazlett-Stevens, Craske, Mayer, Chang, ∗
& Naliboff, 2003). Therefore, the QOL in IBS non-patients also seems to suffer (Frank et al., 2002). There are currently no studies investigating which psychological interventions are effective for IBS non-patients. In a meta-analysis of psychological treatments for IBS patients (Zijdenbos et al., 2009), 84% of studies investigated treatments implemented as part of secondary or tertiary care, and the remainder investigated those implemented as part of primary care. Although treatment for IBS non-patients is needed because about 30% of IBS non-patients become IBS patients within three years (Fujii & Nomura, 2008), many psychological treatments for IBS only target patients with severe symptoms. Among the various forms of CBT, we propose that ACT can function as an intervention for IBS non-patients for three reasons. First, previous studies have shown that ACT for IBS patients is effective in reducing the severity of symptoms and improving QOL (Ferreira, Gillanders, Morris, & Eugenicos, 2017; Gillanders, Ferreira, Angioni, Carvalho, & Eugenicos, 2017). Second, there is evidence suggesting that ACT is effective for subclinical cases. For example, ACT was shown to improve general mental health and reduce overall distress in non-patient college students who were at risk of mental illness (Muto, Hayes, & Jeffcoat, 2011). Third, the treatment mechanism of ACT is appropriate for IBS non-patients’ characteristics. ACT aims to increase psychological flexibility, which comprises acceptance, defusion, contact with the present moment, self-as-context, values, and committed action, and to facilitate behavior that accords with one's personal values (Hayes, Strosahl, &
Corresponding author. Graduate School of Psychology, Doshisha University, 1–3 Tatara-Miyakodani, Kyotanabe, Kyoto, 610-0394, Japan. E-mail addresses: [email protected] (M. Ito), [email protected] (T. Muto).
https://doi.org/10.1016/j.jcbs.2019.11.009 Received 28 March 2019; Received in revised form 25 September 2019; Accepted 27 November 2019 2212-1447/ © 2019 The Authors. Published by Elsevier Inc. on behalf of Association for Contextual Behavioral Science. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/).
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Hsiao, & Kurokawa, 1998). We used three summary scores (Suzukamo et al., 2011): the physical component summary (PCS), the mental component summary (MCS), and the role/social component summary (RCS). Higher scores represent better QOL. Good internal consistency was shown for PCS (Cronbach's α = 0.81-0.86), RCS (Cronbach's α = 0.79-0.89), and MCS (Cronbach's α = 0.88-0.90).
Wilson, 2012). In IBS patients, the improvement of psychological flexibility leads to better QOL (Ferreira et al., 2017). These studies suggest that ACT may be effective for IBS non-patients in reducing the severity of symptoms and improving QOL. The current study aimed to examine the effectiveness of ACT for IBS non-patients. If this intervention is effective for non-patients, we may expect to see improvements in symptom severity, QOL, and psychological distress, along with changes in participants’ psychological flexibility.
2.3.3. Beck Depression Inventory-II (BDI-II) The BDI-II was used to measure depression (Beck, Steer, & Brown, 1996), with higher scores representing more depressive symptoms. The Japanese version of the BDI-II is well-validated (Kojima et al., 2002). In this study, BDI-II showed good internal consistency (Cronbach's α = 0.91-0.94).
2. Materials and methods 2.1. Participants
2.3.4. State-Trait Anxiety Inventory (STAI) The STAI was used to measure state anxiety (STAI-S) and trait anxiety (STAI-T) (Spielberger, Gorsuch, & Lushene, 1983), with higher scores indicating more anxiety. The Japanese version of the STAI has been validated in previous studies (Hidano, Fukuhara, Iwawaki, Soga, & Spielberger, 2000). Good internal consistency was shown for the STAI-S (Cronbach's α = 0.92-0.94), and STAI-T (Cronbach's α = 0.87- 0.92).
Participants were recruited from a university population by means of a screening survey. The screening survey used the Japanese version of the irritable bowel syndrome severity index (IBSSI; Shinozaki et al., 2006). A total of 329 undergraduate students participated in the screening survey. Those who scored above the clinical cut-off score on the IBSSI at screening (200 people) were invited to participate in the study, with 169 declining to do so. Of the remaining 31, five participants recovered to the extent that they scored below the clinical cut-off on the IBSSI at a pre-intervention assessment, and thus were excluded from the study. The remaining 26 participated in this study, and their mean age was 19.9 years (SD = 1.23). Further, the majority of participants were female (61.5%). There were four exclusion criteria: (1) undergoing psychopharmacological or psychological treatment for gastrointestinal or psychiatric disorders; (2) the presence of warning symptoms which suggested the presence of organic disease at the selfreported screening and assessment (e.g., anemia, inflammatory reactions, fecal occult blood, unexplained weight loss in the past six months, or a family history of colon cancer); (3) suicidal ideation; and (4) individuals whom the investigator determined to be unsuitable as participants (e.g., unable to communicate effectively in Japanese).
2.4. Process measures 2.4.1. Acceptance and Action Questionnaire-II (AAQ-II) The AAQ-II was used to assess experiential avoidance, which is the key process targeted in ACT, with higher scores indicating more frequent avoidance. The AAQ-II has been found to have adequate reliability and validity (Bond et al., 2011) and has been translated into Japanese (Shima, Yanagihara, Kawai, & Kumano, 2013). The AAQ had good internal consistency (Cronbach's α = 0.82-0.91). 2.4.2. Cognitive Fusion Questionnaire (CFQ) The CFQ is a 13-item measure of cognitive fusion, which is a component of psychological flexibility, with higher scores indicating more cognitive fusion. This scale has been shown to have good psychometric properties (Gillanders et al., 2014), and the Japanese version has shown similar psychometric properties (Shima, Yanagihara, Kawai, & Kumano, 2014). In the current study, the CFQ had acceptable internal consistency (Cronbach's α = 0.73-0.90).
2.2. Primary outcome measure 2.2.1. Japanese version of the IBS Severity Index (IBSSI) The IBSSI (Francis, Morris, & Whorwell, 1997) was developed to assess the major symptoms of IBS, and it has been translated into Japanese (Shinozaki et al., 2006). This measure consists of 7 items relating to the severity and duration of abdominal pain, severity of abdominal distention, dissatisfaction with bowel habits, and interference in their life, with higher values representing higher levels of severity. Both the original and Japanese versions of IBSSI have pre-determined cut-off scores which indicate mild (75–174), moderate (175–299), or severe (300–500) IBS. The Japanese version of the IBSSI showed acceptable internal consistency (Cronbach's α = 0.69) and test-retest reliability (ICC = 0.86; Shinozaki et al., 2006). However, in the current study, the IBSSI demonstrated lower internal consistency (α = 0.34–0.67) across the assessments.
2.4.3. Five Facet Mindfulness Questionnaire (FFMQ) The FFMQ (Baer et al., 2008) was used to measure five dimensions of mindfulness, with higher scores indicating greater mindfulness. The Japanese version of this questionnaire has been validated (Sugiura, Sato, Ito, & Murakami, 2012). In this study, the FFMQ showed acceptable internal consistency (Cronbach's α = 0.56-0.69). 2.5. Adherence quizzes Adherence multiple-choice quizzes were administered online on six occasions to measure the participants’ use of the workbook. Each quiz consisted of 10 items that were relevant to two or three chapters of the book. Quizzes examined participants understanding of book content (e.g., “In ACT, what part of the issue are you focusing on?“).
2.3. Secondary outcome measures 2.3.1. Japanese version of the IBS-QOL The IBS-QOL instrument (Patrick, Drossman, Frederick, Dicesare, & Puder, 1998) was developed to assess symptom-related QOL, and has been translated into Japanese (Kanazawa et al., 2007), with higher scores indicating a better QOL. Internal consistency was almost identical (Cronbach's α = 0.96 - 0.97) across assessments in the present study.
2.6. Treatment protocol The procedure used in this study followed a treatment protocol used by Ferreira et al. (2017) and published by the Association for Contextual Behavioral Science (Ferreira & Gillanders, 2012a). This protocol consists of two main elements: (1) a one-day group ACT workshop, and (2) a two-month period of self-help using a workbook. The initial workshop did not have any notable changes from the protocol, except that only one facilitator was used (see supplementary material). The first author, who is a licensed clinical psychologist, administered all
2.3.2. Short Form (36) Health Survey (SF-36) The SF-36, developed based on the Medical Outcome Study, is a 36item measure assessing health-related QOL (Ware, Kosinski, & Keller, 1994) and has been translated into Japanese (Fukuhara, Bito, Green, 86
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Fig. 1. Flow chart showing participants' paths through the trial.
this, a post-intervention assessment was administered. Finally, a followup assessment was administered two months after the end of the selfhelp period. At the end of the workshop, participants received a 6000yen (about $57) book token in return for their participation. The waiting list group was offered the same intervention after the follow-up assessment. The study was approved by the research ethics committees of the authors’ affiliated university and registered with the clinical trial registry (UMIN CTR: UMIN000027728).
workshops as the facilitator. At the end of the workshop, all participants were provided with an ACT workbook (Japanese version of Get Out of Your Mind and Into Your Life (Hayes & Smith, 2010)) that aimed to allow them to maintain the workshop content. Previous studies of ACT for IBS patients (Ferreira et al., 2017; Gillanders et al., 2017) have used the workbook Better Living with IBS (Ferreira & Gillanders, 2012b). We changed the workbook because targeting general suffering may be more appropriate for IBS non-patients, who have less severe symptoms than IBS patients, and because a Japanese translation of Better Living with IBS was not available. Moreover, the workbook has been previously shown to be effective with Japanese college students (Muto et al., 2011).
2.8. Data analysis All data analyses were conducted using IBM SPSS Statistics, version 25.0. A last-observation-carried-forward imputation method was used for missing data. For the outcome analysis, we conducted a 2 × 3 mixed-design analysis of variance (ANOVA) on each outcome variable, with group (intervention or waiting list) as a between-person factor and time (pre-intervention, post-intervention, and two-month follow-up) as a within-person factor. In the case of a significant group × time interaction, we investigated the simple main effects using multiple comparisons with the Bonferroni correction procedure. To evaluate clinical significance, we calculated the Reliable Change Index and threshold for clinically significant change for each outcome measure (Jacobson & Truax, 1991). These calculations used values from the validation study of the corresponding instrument.
2.7. Procedure Fig. 1 provides a flow chart representing participants' paths through this experiment. Participants who scored above the cut-off score on the IBSSI were invited by email to participate following the screening survey. The nature and purpose of the study was explained to each potential participant individually, and 31 participants provided informed consent to participate. A pre-intervention assessment was administered one week before the ACT workshop. Ultimately, 26 participants were randomly assigned to an intervention group (n = 14) or a waiting list group (n = 12) using sequentially numbered, opaque, sealed envelope randomization, which was implemented using a computer-generated list (www.random.org.). The intervention group completed the ACT workshop and the self-help program with the workbook over the course of two months. Participants completed six adherence quizzes at intervals of 10 days during the self-help period. Following 87
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Note; p relates to Fisher's exact test; WL = Waiting List; IBSSI = Irritable Bowel Syndrome Severity Index; IBSQOL = Irritable Bowel Syndrome-Quality of Life measure; SF-36 = MOS 36-Item Short-Form Health Survey; PCS = Physical Component Summary; MCS = Mental component Summary; RCS = Role/social Component Summary; BDI = Beck Depression Inventory-II; STAI-S = State-Trait Anxiety Inventory-State; STAI-T = StateTrait Anxiety Inventory-Trait; AAQ = Acceptance and Action Questionnaire-II; CFQ = Cognitive Fusion Questionnaire; FFMQ = Five Facet Mindfulness Questionnaire.
0.91 0.49 0.14 0.50 0.46 0.25 1.21 1.23 1.71 0.48 0.43 0.08 1.3 0.33 1.72 1.44 1.08 1.76 (10.30) (11.52) (9.18) (14.31) (8.56) (4.64) (5.17) (4.94) (2.60) 57.37 38.51 35.37 21.00 49.25 60.00 31.75 56.50 104.50 (2.68) (13.94) (8.20) (11.26) (11.50) (10.09) (13.43) (10.09) (9.18) 56.51 42.98 46.27 15.40 45.20 53.40 23.60 53.80 111.40 (8.12) (7.46) (15.04) (9.58) (10.85) (8.76) (8.56) (10.60) (11.16) 59.16 40.37 42.02 14.14 47.71 54.36 21.57 50.21 116.29
60.62 38.91 39.65 13.44 49.11 54.89 20.44 48.22 111.4
(5.61) (11.17) (13.30) (9.18) (10.91) (8.54) (5.00) (10.92) (11.71)
(1.30) (43.58) (13.92) 19.8 175 85.59 (1.36) (57.79) (14.10) 19.86 194.07 86.13
Age IBSSI IBS-QOL SF-36 PCS MCS RCS BDI-II STAI-S STAI-T AAQ-II CFQ FFMQ
19.89 204.67 86.43 (1.21) (53.46) (13.50)
64.29 Gender (% Female)
66.67
58.11 38.39 44.83 18.38 49.13 59.88 23.75 52.88 111.63 (5.80) (6.25) (14.55) (10.45) (11.60) (7.51) (8.61) (6.93) (8.79) 57.867 38.428 41.68 19.25 49.17 59.92 26.42 54.08 109.25
(8.37) (11.59) (11.08) (9.01) (9.26) (7.20) (6.80) (5.26) (9.52)
(1.50) (115.79) (30.91) 20.75 258.75 67.28 19.63 182.50 78.86 (1.04) (102.01) (23.16) 20.08 207.92 75.00
(0.92) (91.61) (19.55)
50.00 62.50 58.33 60.00
Completer n = 8 Mean (SD) over all n = 12 Mean (SD) over all n = 14 Mean (SD)
Intervention variable
Table 1 Baseline demographics.
Completer n = 9 Mean (SD)
lost to follow up n = 5 Mean (SD)
Wait list
lost to follow up n = 4 Mean (SD)
p .54 t (24) 0.29 0.44 1.53
Intervention vs waiting list
p 0.61 t (24) 0.90 0.55 0.68
completer vs lost to follow up
M. Ito and T. Muto
3. Results 3.1. Preliminary analyses Table 1 shows the results of independent t-tests and Fisher's exact tests at baseline. There was no significant difference between the groups in their characteristics and pre-intervention assessment scores on any measures. Five intervention group participants and four waiting list group participants missed at least one assessment. There was no significant difference between those who completed all assessments and those who did not on their characteristics and measures. Finally, a Fisher's exact test showed that there was no difference in attrition rate between the groups (p = .61). 3.2. Outcome results Table 2 shows the means, standard deviations, results of ANOVA, and effect sizes for the changes between each time point on all outcome measures at pre-intervention assessment, post-intervention assessment, and two-month follow-up. Primary outcomes did not show significant changes. Secondary outcomes showed a significant interaction only on BDI-II. On this measure, the intervention group's scores significantly improved and the waiting list group's scores worsened. Process measures did not show significant interactions. 3.3. Reliable change and clinical significance Table 3 displays the reliable change index, cut-off score for clinical significance, and average change score for participants in each group who completed the relevant assessments for each outcome measure. On an individual level, 40% of participants in the intervention group showed signs of recovery from IBS symptoms (i.e., reliable and clinically significant change on the IBSSI) during the post-intervention assessment, and 20% showed signs of recovery during the follow-up assessment. No participants in the waiting list group showed signs of recovery from IBS symptoms on reliable change scores. Some participants demonstrated signs of recovery at the post-intervention and follow-up assessments on the BDI-II, STAI-S, and STAI-T. 3.4. Treatment compliance Participants in the intervention group completed an average of 2.9 of the 6 adherence quizzes (47.6%). The accuracy rate for their answers was 35.0% (21/60 questions). Outcome measures showed no significant association with compliance measures. 4. Discussion The aim of this study was to evaluate the efficacy of a one-day group ACT program for IBS non-patients. This program led to a significant improvement in depressive mood compared to the waiting list group. In addition, findings with the IBSSI indicated that 40% of participants in the intervention group showed clinically reliable signs of recovery postintervention compared to none of the participants in the control group. These changes that occurred following an ACT program are encouraging for the potential use of this intervention with IBS non-patients. Although the current findings do not support that an ACT intervention may improve the severity of IBS symptoms in IBS non-patients, the IBSSI had some limitations. As this measure showed lower internal consistency, there might be a problem with the reliability of the current results. Moreover, these outcomes showed lower statistical power (1beta = 0.70; alpha = .05, ηp2 = 0.04). These results make conclusions regarding the effect of the intervention on IBS symptoms difficult. This study demonstrated that the ACT program led to some improvement in depressive mood in IBS non-patients, which is consistent with previous studies of ACT (A-Tjak et al., 2015). A meta-analysis 88
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Table 2 All Variables at Pre-intervention, Post-intervention, and 2-Month Follow-up Assessments, ANOVA analysis, and effect sizes. Variable
IBSSI IBS-QOL SF-36 PCS MCS RCS BDI-II STAI-S STAI-T AAQ-II CFQ FFMQ
Mean (SD)a Pre-intervention
Group
Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list Intervention Waiting list
194.07 207.92 86.134 75
Post-intervention
(53.46) (102.01) (13.50) (23.16)
59.156 (8.12) 57.867 (5.80) 40.365 (7.46) 38.428 (6.25) 42.021 (15.04) 41.68 (14.55) 14.14 (9.58) 19.25 (10.45) 47.71 (10.85) 49.17 (11.60) 54.36 (8.76) 59.92 (7.51) 21.57 (8.56) 26.42 (8.61) 50.21 (10.60) 54.08 (6.93) 116.29 (11.16) 109.25 (8.79)
2-month follow-up
group effect F (1,24)
time effect F (2,48)
group*time interaction F (2,48)
Effect (ηp2)
130.00 187.5 84.78 75.07
(89.91) (95.55) (16.64) (17.32)
128.33 174.12 88.24 79.78
(67.92) (75.06) (14.42) (13.86)
1.96
4.45
1.01
.04
2.38
1.02
0.39
.02
62.01 60.03 40.92 39.72 37.51 38.75 13.40 25.70 48.60 53.00 54.50 59.50 23.10 28.50 51.70 52.60 119.20 106.60
(6.50) (9.77) (6.71) (12.06) (11.80) (8.27) (9.97) (12.34) (9.56) (11.03) (10.08) (8.96) (7.74) (6.49) (11.06) (6.77) (12.63) (8.26)
58.6 57.41 47.97 45.49 43.28 38.6 8.00 22.25 43.22 50 48.33 60.63 18.33 27 41.89 49.87 125.89 111.25
(3.22) (5.99) (10.77) (10.71) (12.41) (11.20) (8.06) (13.13) (13.09) (7.78) (11.63) (20.40) (8.20) (6.89) (15.19) (5.79) (23.07) (10.96)
0.09
2.45
0.18
.01
0.6
8.33
0.37
.02
0.37
1.62
0.88
.04
5.33
2.51
10.17**
.30
1.03
1.75
1.64
.06
3.34
0.60
0.94
.04
4.30
0.95
1.67
.07
1.01
2.54
0.50
0.02
6.11
0.69
1.05
0.04
Effect size (within Cohen's d) pre post
pre - 2 month FU
0.97 0.41 0.20 0.01
1.32 0.33 0.36 0.36
0.20 0.36 0.30 0.21 0.18 0.35 0.15 1.42 0.10 0.73 0.02 0.09 0.36 0.33 0.31 0.22 0.23 0.34
0.08 0.10 0.84 0.93 0.13 0.15 1.10 0.56 0.35 0.08 0.62 0.04 0.53 0.07 0.71 0.61 0.58 0.48
Note. Effect size (within Cohen's d) defined as [(mean1−mean2)/SQRT [(SD1)2 + (SD2)2)/2)]]/SQRT (2*(1-r))]. FU = Follow-up; IBSSI = Irritable Bowel Syndrome Severity Index; IBS-QOL = Irritable Bowel Syndrome-Quality of Life measure; SF-36 = 36-item Short-Form Health Survey; PCS = Physical Component Summary; MCS = Mental Component Summary; RCS = Role/social Component Summary; BDI-II = Beck Depression Inventory-II; STAI-S = State-Trait Anxiety InventoryState; STAI-T = State-Trait Anxiety Inventory-Trait; AAQ-II = Acceptance and Action Questionnaire-II; CFQ = Cognitive Fusion Questionnaire; FFMQ = Five Facet Mindfulness Questionnaire. aRaw means, without adjustment for missing values.
better outcomes. These results suggest that the current intervention did not lead to consistent practice in daily life. Therefore, in the case of such participants, it may be necessary to modify the intervention to provide more support aimed at maintaining their practice. It should be borne in mind, however, that the participants in the present study were IBS non-patients, who may have been less motivated to engage in treatment than patients (DiMatteo, Haskard, & Williams, 2007). For example, a study using internet-delivered self-help for IBS patients found that this method of delivery provides greater accessibility (Ljótsson et al., 2010). Their intervention, which is similar to ACT, showed a positive effect on IBS symptoms, and participants actively utilized their program. These findings show that modifying the method by which self-help is offered can lead to an increase in practice in daily life and thereby a more effective intervention.
study showed that depression is associated with a twofold risk for IBS onset (Sibelli et al., 2016). Additionally, the severity of IBS symptoms was predicted by psychological distress (Phillips, Wright, & Kent, 2013). As the current intervention appears to have improved participant's depressive symptoms, this improvement may lead to preventing IBS symptoms becoming more severe. The results suggest a possibility that empowering participants to engage in the practice of ACT skills can lead to improvement in outcomes and psychological flexibility. The previous study of IBS patients (Ferreira et al., 2017) found that 82.2% of participants reported using the workbook, and these participants showed improvement in IBS severity and QOL. Another previous study (Muto et al., 2011) using adherence test showed a higher rate of completion and correct answers than those in the current study, and their higher compliance rate lead to Table 3 Reliable and Clinically Significant Change in each Group. RC
IBSSI
59.94
Cut-off score
< 81* †
IBS-QOL
11.06
> 80
BDI-II
7.82
< 12*
STAI-S
9.17
< 47*
STAI-T
11.64
< 52*
group
Int WL Int WL Int WL Int WL Int WL
Pre - Post
Pre - 2-month follow-up
Average Change
RC%
RC and CS%
Average change
RC%
RC and CS%
78.20 26.50 0.66 −3.31 2.10 −5.30 1.90 −1.60 1.70 −1.50
60.00 10.00 0.00 12.50 0.00 0.00 0.00 0.00 10.00 0.00
40.00 0.00 0.00 12.50 0.00 0.00 0.00 0.00 10.00 0.00
76.33 8.37 1.80 −0.92 5.44 −3.88 5.89 −0.88 6.56 −0.75
44.44 25.00 0.00 12.50 22.22 0.00 11.11 0.00 22.22 0.00
22.22 0.00 0.00 12.50 11.11 0.00 11.11 0.00 22.22 0.00
Note. RC = reliable change, defined as 1.96 * SQRT(2) * SQRT(1- alpha); CS = clinically significant; IBSSI = Irritable Bowel Syndrome Severity Index; IBS-QOL = Irritable Bowel Syndrome-Quality of Life measure; BDI-II = Beck Depression Inventory-II; STAI-S = State-Trait Anxiety Inventory-State; STAI-T = State-Trait Anxiety Inventory-Trait. *Cut-off score was determined by the results of a validation study (IBSSI: Francis et al., 1997; BDI-II: Kojima et al., 2002; STAI-S, STAI-T: Hidano et al., 2000). †Cut-off score was determined by suggested cut-off (Cañón et al., 2017). 89
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starting point for interventions with IBS non-patients, and future modifications of the method of the intervention may lead to improved health for IBS non-patients.
In summary, this study found that an ACT program targeting IBS non-patients was not sufficient to improve IBS symptoms. On the other hand, it could be argued that the improvement in depressive symptoms is a positive change for IBS non-patients. Although the resulting changes in depression and IBS symptoms appear encouraging, more studies are needed to investigate the levels of improvement. Encouraging interventions that lead to increased self-help may lead to greater improvement. Overall, the results of this study provide a
Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Appendix A Example questions of adherence tests Q. In ACT, what part of the issue are you focusing on? 1. Form 2. Situation Q. What does it mean to “ride your mind-train”? 1. To do something automatically and uncon2. Doubt the language sciously Q. Why are people stuck in the system of experiential avoidance? 1. Eliminating unpleasant things works well 2. Making the problem bigger Q. What does the metaphor of the “hungry tiger” mean? 1. The dangers of feeding animals 2. Avoidance is not an effective approach Q. What was the purpose of the exercise of “floating leaves in a moving stream”? 1. Letting one's thoughts wander 2. Understanding one's thoughts Q. What does chessboard mean in the chess metaphor? 1. A place with emotions 2. Thoughts and emotion Q. What is a good way to establish daily mindfulness practice? 1. Taking time 2. Enjoying Q. What are the limits of the willingness to your experience? 1. Public restrictions 2. The quality of private experience Q. While “physicalizing”, you usually 1. Feel good 2. Get tired Q. What are values? 1.Achievement 2. Direction Q. How do you check to see that you have met your goal? 1. Feel better 2. Feasibility Q. In ACT, how do you approach barriers? 1. Making a detour 2. Breaking the barrier
3. Function
4. Disorder
3. Being confident
4. Being distressed
3. Eliminating unpleasant situations
4. Coping with the problem
3. The effectiveness of avoidance
4. A tiger becomes ferocious
3. Ignoring one's thoughts
4. Distancing oneself from thoughts
3. Perceiving thoughts and emotions objectively
4. A place to think
3. Stop when you feel sick
4. Relaxing
3.The degree of private experience
4. The magnitude of anxiety
3. Feel ridiculous about doing the exercises
4. Are easy to accept
3. Objective
4. Goal
3.Engage in enjoyable activities
4. Achievements
3. Getting along the barriers
4. Getting over the barriers
Appendix B. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.jcbs.2019.11.009.
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