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Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)

Authors:

Abstract

BACKGROUND: Cognitive behavioural therapy (CBT) is an evidence-based treatment for anxiety disorders. Many people have difficulty accessing treatment, due to a variety of obstacles. Researchers have therefore explored the possibility of using the Internet to deliver CBT; it is important to ensure the decision to promote such treatment is grounded in high quality evidence. OBJECTIVES: To assess the effects of therapist-supported Internet CBT on remission of anxiety disorder diagnosis and reduction of anxiety symptoms in adults as compared to waiting list control, unguided CBT, or face-to-face CBT. Effects of treatment on quality of life and patient satisfaction with the intervention were also assessed. SEARCH METHODS: We searched the Cochrane Depression, Anxiety and Neurosis Review Group Specialized Register (CCDANCTR) to 12 April 2013. The CCDANCTR includes relevant randomised controlled trials from EMBASE (1974 -), MEDLINE (1950 -) and PsycINFO (1967 -). We also searched online clinical trial registries and reference lists of included studies. We contacted authors to locate further trials. An update of an initial search (April 2013), conducted in September 2014, identified seven new completed studies, seven previously ongoing studies now completed, and four new ongoing studies. This is a fast-moving area; we plan to update this review shortly, incorporating these new studies. SELECTION CRITERIA: Each identified study was independently assessed for inclusion by two authors. To be included, studies had to be randomised controlled trials of therapist-supported ICBT compared to a waiting list, attention, information, or online discussion group; unguided CBT (that is, self-help); or face-to-face CBT. We included studies that treated adults with an anxiety disorder (panic disorder, agoraphobia, social phobia, post-traumatic stress disorder, acute stress disorder, generalized anxiety disorder, obsessive compulsive disorder, and specific phobia) defined according to the Diagnostic and Statistical Manual of Mental Disorders III, III-R, IV, IV-TR or the International Classification of Disesases 9 or 10. DATA COLLECTION AND ANALYSIS: Two authors independently assessed the risk of bias of included studies and judged overall study quality. We used data from intention-to-treat analyses wherever possible. We assessed treatment effect for the dichotomous outcome of clinically important improvement in anxiety using a risk ratio (RR) with 95% confidence interval (CI). For disorder-specific and general anxiety symptom measures and quality of life we assessed continuous scores using standardized mean differences (SMD). We examined statistical heterogeneity using the I(2) statistic. MAIN RESULTS: We screened 1000 citations and selected 30 studies (2181 participants) for inclusion. The studies examined social phobia (11 trials), panic disorder with or without agoraphobia (8 trials), generalized anxiety disorder (4 trials), post-traumatic stress disorder (1 trial), and specific phobia (1 trial). Five remaining studies included a range of anxiety disorder diagnoses. Studies were conducted in Sweden (15 trials), Australia (12 trials), Switzerland (2 trials), and the Netherlands (1 trial) and investigated a variety of ICBT protocols. Three primary comparisons were identified, experimental versus waiting list control, experimental versus unguided ICBT, and experimental versus face-to-face CBT.Moderate quality evidence from 9 studies (644 participants) contributed to a pooled RR of 4.18 (95% CI 2.42 to 7.22) for clinically important improvement in anxiety at post-treatment, favouring therapist-supported ICBT over a waiting list, attention, information, or online discussion group only. Similarly, the SMD for disorder-specific symptoms at post-treatment (22 studies, 1573 participants; SMD -1.12, 95% CI -1.39 to -0.85) and general anxiety symptoms at post-treatment (14 studies, 1004 participants; SMD -0.79, 95% CI -1.10 to -0.48) favoured therapist-supported ICBT. The quality of the evidence for both outcomes was low.One study compared unguided CBT to therapist-supported ICBT for clinically important improvement in anxiety at post-treatment, showing no difference in outcome between treatments (54 participants; very low quality evidence). At post-treatment there were no clear differences between unguided CBT and therapist-supported ICBT for disorder-specific anxiety symptoms (4 studies, 253 participants; SMD -0.24, 95% CI -0.69 to 0.21; low quality evidence) or general anxiety symptoms (two studies, 138 participants; SMD 0.28, 95% CI -2.21 to 2.78; low quality evidence).Compared to face-to-face CBT, therapist-supported ICBT showed no significant differences in clinically important improvement in anxiety at post-treatment (4 studies, 365 participants; RR 1.09, 95% CI 0.89 to 1.34; moderate quality evidence). There were also no clear differences between face-to-face and therapist supported ICBT for disorder-specific anxiety symptoms at post-treatment (6 studies, 424 participants; SMD 0.09, 95% CI -0.26 to 0.43; low quality evidence) or general anxiety symptoms at post-treatment (5 studies, 317 participants; SMD 0.17, 95% CI -0.35 to 0.69; low quality evidence).Overall, risk of bias in included studies was low or unclear for most domains. However, due to the nature of psychosocial intervention trials, blinding of participants and personnel, and outcome assessment tended to have a high risk of bias. Heterogeneity across a number of the meta-analyses was substantial, some was explained by type of anxiety disorder or may be meta-analytic measurement artefact due to combining many assessment measures. Adverse events were rarely reported. AUTHORS' CONCLUSIONS: Therapist-supported ICBT appears to be an efficacious treatment for anxiety in adults. The evidence comparing therapist-supported ICBT to waiting list, attention, information, or online discussion group only control was low to moderate quality, the evidence comparing therapist-supported ICBT to unguided ICBT was low to very low quality, and comparisons of therapist-supported ICBT to face-to-face CBT was low to moderate quality. Further research is needed to better define and measure any potential harms resulting from treatment. These findings suggest that therapist-supported ICBT is more efficacious than a waiting list, attention, information, or online discussion group only control, and that there may not be a significant difference in outcome between unguided CBT and therapist-supported ICBT; however, this latter finding must be interpreted with caution due to imprecision. The evidence suggests that therapist-supported ICBT may not be significantly different from face-to-face CBT in reducing anxiety. Future research should involve equivalence trials comparing ICBT and face-to-face CBT, examine the importance of the role of the therapist in ICBT, and include effectiveness trials of ICBT in real-world settings. A timely update to this review is needed given the fast pace of this area of research.
Seediscussions,stats,andauthorprofilesforthispublicationat:http://www.researchgate.net/publication/273148127
Therapist-supportedInternetcognitive
behaviouraltherapyforanxietydisordersin
adults
ARTICLEinCOCHRANEDATABASEOFSYSTEMATICREVIEWS(ONLINE)·MARCH2015
ImpactFactor:6.03·DOI:10.1002/14651858.CD011565·Source:PubMed
CITATIONS
2
READS
129
5AUTHORS,INCLUDING:
MargoC.Watt
St.FrancisXavierUniversity
52PUBLICATIONS649CITATIONS
SEEPROFILE
SherryHStewart
DalhousieUniversity
400PUBLICATIONS8,539CITATIONS
SEEPROFILE
Availablefrom:SherryHStewart
Retrievedon:07October2015
Therapist-supported Internet cognitive behavioural therapy
for anxiety disorders in adults (Review)
Olthuis JV, Watt MC, Bailey K, Hayden JA, Stewart SH
This is a reprint of a Cochrane review, prepared and maintained by The Cochrane Collaboration and published in The Cochrane Library
2015, Issue 3
http://www.thecochranelibrary.com
Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
T A B L E O F C O N T E N T S
1HEADER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2PLAIN LANGUAGE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4SUMMARY OF FINDINGS FOR THE MAIN COMPARISON . . . . . . . . . . . . . . . . . . .
7BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
26ADDITIONAL SUMMARY OF FINDINGS . . . . . . . . . . . . . . . . . . . . . . . . . .
33DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36AUTHORS’ CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49CHARACTERISTICS OF STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
138DATA AND ANALYSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analysis 1.1. Comparison 1 Therapist-supported ICBT versus waiting list control, Outcome 1 Clinically Important
Improvement in Anxiety at Post-Treatment. . . . . . . . . . . . . . . . . . . . . . . . 140
Analysis 1.2. Comparison 1 Therapist-supported ICBT versus waiting list control, Outcome 2 Anxiety Symptom Severity
at Post-Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Analysis 1.3. Comparison 1 Therapist-supported ICBT versus waiting list control, Outcome 3 General Anxiety Symptom
Severity at Post-Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Analysis 1.4. Comparison 1 Therapist-supported ICBT versus waiting list control, Outcome 4 Quality of Life at Post-
Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Analysis 2.1. Comparison 2 Therapist-supported ICBT versus unguided CBT, Outcome 1 Clinically Important
Improvement in Anxiety at Post-Treatment. . . . . . . . . . . . . . . . . . . . . . . . 145
Analysis 2.2. Comparison 2 Therapist-supported ICBT versus unguided CBT, Outcome 2 Anxiety Symptom Severity at
Post-Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Analysis 2.3. Comparison 2 Therapist-supported ICBT versus unguided CBT, Outcome 3 Anxiety Symptom Severity at
Follow-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Analysis 2.4. Comparison 2 Therapist-supported ICBT versus unguided CBT, Outcome 4 General Anxiety Symptom
Severity at Post-Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Analysis 2.5. Comparison 2 Therapist-supported ICBT versus unguided CBT, Outcome 5 General Anxiety Symptom
Severity at Follow-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Analysis 2.6. Comparison 2 Therapist-supported ICBT versus unguided CBT, Outcome 6 Quality of Life at Post-
Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Analysis 2.7. Comparison 2 Therapist-supported ICBT versus unguided CBT, Outcome 7 Quality of Life at Follow-up. 149
Analysis 3.1. Comparison 3 Therapist-supported ICBT versus face-to-face CBT, Outcome 1 Clinically Important
Improvement in Anxiety at Post-Treatment. . . . . . . . . . . . . . . . . . . . . . . . 150
Analysis 3.2. Comparison 3 Therapist-supported ICBT versus face-to-face CBT, Outcome 2 Clinically Important
Improvement in Anxiety at Follow-up. . . . . . . . . . . . . . . . . . . . . . . . . . 151
Analysis 3.3. Comparison 3 Therapist-supported ICBT versus face-to-face CBT, Outcome 3 Anxiety Symptom Severity at
Post-Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Analysis 3.4. Comparison 3 Therapist-supported ICBT versus face-to-face CBT, Outcome 4 Anxiety Symptom Severity at
Follow-Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Analysis 3.5. Comparison 3 Therapist-supported ICBT versus face-to-face CBT, Outcome 5 General Anxiety Symptom
Severity at Post-Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
iTherapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
Analysis 3.6. Comparison 3 Therapist-supported ICBT versus face-to-face CBT, Outcome 6 General Anxiety Symptom
Severity at Follow-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Analysis 3.7. Comparison 3 Therapist-supported ICBT versus face-to-face CBT, Outcome 7 Quality of Life at Post-
Treatment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Analysis 3.8. Comparison 3 Therapist-supported ICBT versus face-to-face CBT, Outcome 8 Quality of Life at Follow-
up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
157ADDITIONAL TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
179APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
180CONTRIBUTIONS OF AUTHORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
180DECLARATIONS OF INTEREST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
180SOURCES OF SUPPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
181DIFFERENCES BETWEEN PROTOCOL AND REVIEW . . . . . . . . . . . . . . . . . . . . .
182NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
iiTherapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
[Intervention Review]
Therapist-supported Internet cognitive behavioural therapy
for anxiety disorders in adults
Janine V Olthuis1, Margo C Watt2, Kristen Bailey3, Jill A Hayden4, Sherry H Stewart5
1Department of Psychology and Neuroscience, Dalhousie University, Halifax, Canada. 2Psychology, Saint Francis Xavier University,
Antigonish, Canada. 3Department of Psychology and Neuroscience, Dalhousie University & IWK Health Centre, Halifax, Canada.
4Department of Community Health & Epidemiology, Dalhousie University, Halifax, Canada. 5Departments of Psychiatry, Psychology
and Neuroscience, and Community Health and Epidemiology, Dalhousie University, Halifax, Canada
Contact address: Janine V Olthuis, Department of Psychology and Neuroscience, Dalhousie University, 1355 Oxford Street, Halifax,
NS, B3H 4J1, Canada. janine.olthuis@dal.ca.
Editorial group: Cochrane Depression, Anxiety and Neurosis Group.
Publication status and date: New, published in Issue 3, 2015.
Review content assessed as up-to-date: 12 April 2013.
Citation: Olthuis JV, Watt MC, Bailey K, Hayden JA, Stewart SH. Therapist-supported Internet cognitive behavioural ther-
apy for anxiety disorders in adults. Cochrane Database of Systematic Reviews 2015, Issue 3. Art. No.: CD011565. DOI:
10.1002/14651858.CD011565.
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
A B S T R A C T
Background
Cognitive behavioural therapy (CBT) is an evidence-based treatment for anxiety disorders. Many people have difficulty accessing
treatment, due to a variety of obstacles. Researchers have therefore explored the possibility of using the Internet to deliver CBT; it is
important to ensure the decision to promote such treatment is grounded in high quality evidence.
Objectives
To assess the effects of therapist-supported Internet CBT on remission of anxiety disorder diagnosis and reduction of anxiety symptoms
in adults as compared to waiting list control, unguided CBT, or face-to-face CBT. Effects of treatment on quality of life and patient
satisfaction with the intervention were also assessed.
Search methods
We searched the Cochrane Depression, Anxiety and Neurosis Review Group Specialized Register (CCDANCTR) to 12 April 2013.
The CCDANCTR includes relevantrandomised controlled trials from EMBASE (1974 -), MEDLINE (1950 -) and PsycINFO (1967
-). We also searched online clinical trial registries and reference lists of included studies. We contacted authors to locate further trials.
An update of an initial search (April 2013), conducted in September 2014, identified seven new completed studies, seven previously
ongoing studies now completed, and four new ongoing studies. This is a fast-moving area; we plan to update this review shortly,
incorporating these new studies.
Selection criteria
Each identified study was independently assessed for inclusion by two authors. To be included, studies had to be randomised controlled
trials of therapist-supported ICBT compared to a waiting list, attention, information, or online discussion group; unguided CBT (that
is, self-help); or face-to-face CBT. We included studies that treated adults with an anxiety disorder (panic disorder, agoraphobia, social
phobia, post-traumatic stress disorder, acute stress disorder, generalized anxiety disorder, obsessive compulsive disorder, and specific
phobia) defined according to the Diagnostic and Statistical Manual of Mental Disorders III, III-R, IV, IV-TR or the International
Classification of Disesases 9 or 10.
1Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
Data collection and analysis
Two authors independently assessed the risk of bias of included studies and judged overall study quality. We used data from intention-
to-treat analyses wherever possible. We assessed treatment effect for the dichotomous outcome of clinically important improvement in
anxiety using a risk ratio (RR) with 95% confidence interval (CI). For disorder-specific and general anxiety symptom measures and
quality of life we assessed continuous scores using standardized mean differences (SMD). We examined statistical heterogeneity using
the I2statistic.
Main results
We screened 1000 citations and selected 30 studies (2181 participants) for inclusion. The studies examined social phobia (11 trials),
panic disorder with or without agoraphobia (8 trials), generalized anxiety disorder (4 trials), post-traumatic stress disorder (1 trial), and
specific phobia (1 trial). Five remaining studies included a range of anxiety disorder diagnoses. Studies were conducted in Sweden (15
trials), Australia (12 trials), Switzerland (2 trials), and the Netherlands (1 trial) and investigated a variety of ICBT protocols. Three
primary comparisons were identified, experimental versus waiting list control, experimental versus unguided ICBT, and experimental
versus face-to-face CBT.
Moderate quality evidence from 9 studies (644 participants) contributed to a pooled RR of 4.18 (95% CI 2.42 to 7.22) for clinically
important improvement in anxiety at post-treatment, favouring therapist-supported ICBT over a waiting list, attention, information,
or online discussion group only. Similarly, the SMD for disorder-specific symptoms at post-treatment (22 studies, 1573 participants;
SMD -1.12, 95% CI -1.39 to -0.85) and general anxiety symptoms at post-treatment (14 studies, 1004 participants; SMD -0.79, 95%
CI -1.10 to -0.48) favoured therapist-supported ICBT. The quality of the evidence for both outcomes was low.
One study compared unguided CBT to therapist-supported ICBT for clinically important improvement in anxiety at post-treatment,
showing no difference in outcome between treatments (54 participants; ver y low quality evidence). At post-treatment there were no clear
differences between unguided CBT and therapist-supported ICBT for disorder-specific anxiety symptoms (4 studies, 253 participants;
SMD -0.24, 95% CI -0.69 to 0.21; low quality evidence) or general anxiety symptoms (two studies, 138 participants; SMD 0.28, 95%
CI -2.21 to 2.78; low quality evidence).
Compared to face-to-face CBT, therapist-supported ICBT showed no significant differences in clinically important improvement in
anxiety at post-treatment (4 studies, 365 participants; RR 1.09, 95% CI 0.89 to 1.34; moderate quality evidence). There were also
no clear differences between face-to-face and therapist supported ICBT for disorder-specific anxiety symptoms at post-treatment (6
studies, 424 participants; SMD 0.09, 95% CI -0.26 to 0.43; low quality evidence) or general anxiety symptoms at post-treatment (5
studies, 317 participants; SMD 0.17, 95% CI -0.35 to 0.69; low quality evidence).
Overall, risk of bias in included studies was low or unclear for most domains. However, due to the nature of psychosocial intervention
trials, blinding of participants and personnel, and outcome assessment tendedto have a high risk of bias. Heterogeneity across anumber
of the meta-analyses was substantial, some was explained by type of anxiety disorder or may be meta-analytic measurement artefact due
to combining many assessment measures. Adverse events were rarely reported.
Authors’ conclusions
Therapist-supported ICBT appears to be an efficacious treatment for anxiety in adults. The evidence comparing therapist-supported
ICBT to waiting list, attention, information, or online discussion group only control was low to moderate quality, the evidence
comparing therapist-supported ICBT to unguided ICBT was low to very low quality, and comparisons of therapist-supported ICBT
to face-to-face CBT was low to moderate quality. Further research is needed to better define and measure any potential harms resulting
from treatment. These findings suggest that therapist-supported ICBT is more efficacious than a waiting list, attention, information,
or online discussion group only control, and that there may not be a significant difference in outcome between unguided CBT and
therapist-supported ICBT; however, this latter finding must be interpreted with caution due to imprecision. The evidence suggests that
therapist-supported ICBT may not be significantly different from face-to-face CBT in reducing anxiety. Future research should involve
equivalence trials comparing ICBT and face-to-face CBT, examine the importance of the role of the therapist in ICBT, and include
effectiveness trials of ICBT in real-world settings. A timely update to this review is needed given the fast pace of this area of research.
P L A I N L A N G U A G E S U M M A R Y
Internet-based cognitive behavioural therapy with therapist support for anxiety in adults: a review of the evidence
2Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
Who may be interested in this review?
People who suffer from anxiety and their families.
General Practitioners.
Professionals working in psychological therapy services.
Developers of Internet-based therapies for mental health problems.
Why is this review important?
Many adults suffer from anxiety disorders, which have a significant impact on their everyday lives. Anxiety disorders often result in
high healthcare costs and high costs to society due to absence from work and reduced quality of life. Research has shown that cognitive
behavioural therapy (CBT) is an effective treatment which helps to reduce anxiety. However, many people are not able to access face-to-
face CBT due to long waiting lists, lack of available time for appointments, transportation problems, and limited numbers of qualified
therapists.
Internet-based CBT (ICBT) provides a possible solution to overcome many of the barriers to accessing face-to-face therapy. Therapists
can provide support to patients who are accessing Internet-based therapy by telephone or e-mail. It is hoped that this will provide a way
of increasing access to CBT, particularly for people who live in rural areas. It is not yet known whether ICBT with therapist support is
effective in reducing symptoms of anxiety.
What questions does this review aim to answer?
This review aims to summarise current research to find out whether ICBT with therapist support is an effective treatment for anxiety.
The review aims to answer the following questions:
- is ICBT with therapist support more effective than no treatment (waiting list)?
- how effective is ICBT with therapist support compared with face-to-face CBT?
- how effective is ICBT with therapist support compared with unguided CBT (self-help with no therapist input)?
- what is the quality of current research on ICBT with therapist support for anxiety?
Which studies were included in the review?
Databases were searched to find all high quality studies of ICBT with therapist support for anxiety published until May 2013. To be
included in the review, studies had to be randomised controlled trials involving adults over 18 years with a main diagnosis of an anxiety
disorder; 30 studies with a total of 2181 participants were included in the review.
What does the evidence from the review tell us?
ICBT with therapist support was significantly more effective than no treatment (waiting list) at improving anxiety and reducing
symptoms. The quality of the evidence was low to moderate.
There was no significant difference in the effectiveness of ICBT with therapist support and unguided CBT, though the quality of the
evidence was low to very low. Patient satisfaction was generally reported to be higher with therapist-supported ICBT, however patient
satisfaction was not formally assessed.
ICBT with therapist support may not differ in effectiveness as compared to face-to-face CBT. The quality of the evidence was low to
moderate.
There was a low risk of bias in the included studies, except for blinding of participants, personnel, and outcome assessment. Adverse
events were rarely reported in the studies.
3Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
S U M M A R Y O F F I N D I N G S F O R T H E M A I N C O M P A R I S O N [Explanation]
Therapist-Supported ICBT compared to waiting list, attention, information, or online discussion group only control for anxiety disorders in adults
Patient or population: patients with anxiety disorders
Settings: outpatient care via Internet with e-mail or telephone support, or both
Intervention: therapist-supported ICBT
Comparison: waiting list, attention, information, or online discussion group only control
Outcomes Illustrative comparative risks* (95% CI) Relative effect
(95% CI)
No of participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed risk Corresponding risk
Waiting list, attention,
information, or online
discussion group only
controll
Therapist-supported
ICBT
Clinically important im-
provement in anxiety at
post-treatment
Indexed by a standard-
ized interview or clinically
accepted measure cut-off
score1
Study population RR 4.18
(2.42 to 7.22)
644
(9 studies)
⊕⊕⊕
moderate2
13 per 100 54 per 100
(31 to 93)
Moderate
8 per 100 33 per 100
(19 to 57)
Anxiety symptom sever-
ity at post-treatment
Indexed by a range of dis-
order-specific self-report
measures
The mean anxiety symp-
tom severity at post-treat-
ment in the intervention
groups was
1.12 standard deviations
lower
(1.39 to 0.85 lower)
1573
(24 studies)
⊕⊕
low3,4,5
A standard deviation of 0.
80 or greater represents a
large difference between
groups6
4Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
General anxiety symp-
tom severity at post-
treatment
Indexed by a range
of measures of anxiety
symptoms in general
The mean general anxi-
ety symptom severity at
post-treatment in the in-
tervention groups was
0.79 standard deviations
lower
(1.1 to 0.48 lower)
1004
(14 studies)
⊕⊕
low4,5,7
A standard deviation of 0.
80 or greater represents a
large difference between
groups6
Quality of life at post-
treatment
Indexed by self-report
measures of quality of life
or functional disability
The mean quality of life
at post-treatment in the
intervention groups was
0.51 standard deviations
higher
(0.4 to 0.61 higher)
1395
(20 studies)
⊕⊕⊕
moderate4,7
A standard deviation of
0.50 represents a mod-
erate difference between
groups6
Adverse events at post-
treatment
not reported
Study population Not estimable 0
(0)
See comment Because adverse events
were so rarely reported,
they could not be mean-
ingfully reported by com-
parison and are instead
described in the review
text
See comment See comment
Moderate
Participant satisfaction
Indexed by a mix of
qualitative and quantita-
tive self-report measures
Study population Not estimable 0
(13)
See comment Studies reported high
overall treatment satis-
faction for therapist-sup-
ported ICBT
See comment See comment
Moderate
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the
assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio
5Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.
1For clinically important improvement in anxiety, an event is indicative of a participant achieving clinically important improvement.
2Downgraded for risk of bias (-1) primarily because three of the included studies did not blind their outcome assessors to participants’
group assignment. Not downgraded for inconsistency (0) because heterogeneity was reduced following subgroup analysis by anxiety
disorder.
3Downgraded for risk of bias (-1) primarily due to concerns with selective outcome reporting in a few studies.
4Risk of bias (0). While participants in the included studies were not blind to their treatment condition when completing self-report
measures and therapists were not blind to the treatment they were delivering, these study characteristics cannot be avoided in this type
of clinical treatment.
5Downgraded for inconsistency (-1) because the heterogeneity amongst the included studies was quite high. This may be explained
by the variety of anxiety disorders investigated and differences in the treatment details; however, the number of studies that could be
included in subgroup analyses was not sufficient to provide useful reasons for this heterogeneity.
6According to Cohen’s (1969) interpretation of effect sizes.
7Downgraded for risk of bias (-1) primarily because two studies included baseline imbalances in participant severity across study
groups.
6Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
B A C K G R O U N D
Description of the condition
Individuals with anxiety disorders experience excessive anxiety
(fear or worry) which is disproportionate to actual threat or dan-
ger and significantly interferes with normal daily functioning.
Anxiety disorders can include a range of physical (for example,
trembling, tense muscles, rapid breathing), cognitive (for exam-
ple, worries, difficulty concentrating), emotional (for example,
distress, negative affect, irritability), and behavioural (for exam-
ple, difficulty sleeping, hyperarousal) symptoms. Often those with
anxiety disorders develop maladaptive strategies to lessen anxi-
ety, such as avoidance (Health Canada 2002;Wilson 2006) or
substance use (Stewart 2008). Studies from Canada (Statistics
Canada 2004), the USA (Kessler 2005a), Australia (Slade 2007),
Nigeria (Gureje 2006), and Europe (ESEMeD/MHEDEA 2000
Investigators 2004) suggest that 6% to 18% of adults experience
an anxiety disorder every year. Moreover, rates of remission within
one year are low, that is, from 33% to 42% across specific anxiety
disorders (Robins 1991).
There are many types of anxiety disorders,including panic disorder
(PD), agoraphobia, social phobia, post-traumatic stress disorder
(PTSD), acute stress disorder, generalized anxiety disorder (GAD),
obsessive compulsive disorder (OCD), and specific phobia. These
are diagnosed according to criteria outlined in the Diagnostic and
Statistical Manual of Mental Disorders (DSM IV-R) (APA 2000)
or the International Classification of Diseases (ICD 10) (WHO
1999). Anxiety disorders often co-occur with each other (Kessler
2005a) as well as with mood disorders (Fava 2000) and substance
abuse or dependence (Stewart 2008). They tend to have an early
onset (Kessler 2005b) and chronic course (Bruce 2005). Anxiety
disorders also have a major economic impact; for instance, costs
of direct treatment, unnecessary medical treatment, and work ab-
sences or lost productivity amount to more than USD 40 billion
per year in the United States (DuPont 1996;Greenberg 1999).
Studies have shown significantly higher annual per capita medical
costs for primary care patients with social phobia than for those
with no mental health diagnosis (GBP 11,952 and EUR 2957 re-
spectively) (Acarturk 2009); primary care patients with PD versus
those with a chronic somatic condition (EUR 10,269 versus EUR
3019) (Batelaan 2007); and primary care patients with GAD as
compared to those without GAD (USD 2375 versus USD 1448)
(Revicki 2012).
Description of the intervention
Accumulating research supports the efficacy of CBT in the treat-
ment of anxiety disorders (Bisson 2007;Hunot 2007;Norton
2007;Stewart 2009) and anxiety symptoms (Deacon 2004). As its
name suggests, CBT includes both cognitive as well as behavioural
interventions or techniques. It has no one ’founder’ and now exists
in many different forms. Its roots, however, lie largely in the work
of Aaron Beck (Beck 1979). While pharmacotherapy (most com-
monly, benzodiazepines or selective serotonin reuptake inhibitors)
has been shown to be effective in the treatment of anxiety disor-
ders, meta-analyses and review articles suggest that CBT is as e ffec-
tive in the acute phase of anxiety and may be more effective than
pharmacotherapy or a combination of both treatments in the long
term (Westra 1998;Otto 2000;Otto 2005;Pull 2007). More-
over, some anxiety medications pose significant risk for addiction
(McNaughton 2008) or serious side effects, or both (Buffett-Jerrot
2002;Choy 2007).
Unfortunately, certain barriers (for example, time constraints,
transportation problems, stigma, long waiting lists, a lack of suf-
ficiently qualified clinicians) continue to limit access to CBT
(Alvidrez 1999;Young 2001;Mohr 2006). Many of these bar-
riers are particularly relevant for those living in rural communi-
ties (Yuen 1996;Rost 2002;Hauenstein 2006). National surveys
in Canada (Statistics Canada 2004) and the US (Kessler 2004)
suggested that less than one third (only 32% and 20%, respec-
tively) of those with a current psychiatric disorder received some
form of treatment in the past year. In a Canadian sample, only
11% of individuals with an anxiety disorder had received treat-
ment (Ohayon 2000). Increasingly, efforts are being made to im-
prove access to CBT on a large scale, particularly for those groups
who are most at risk due to lack of services (for example, the UK-
based National Health Service ’Improving Access to Psychological
Therapies’ (IAPT) programme launched in 2006) (Department
of Health 2008). A distance delivery approach wherein CBT is
delivered over the Internet with a therapist providing support by
telephone or e-mail is one way to minimize treatment barriers and
increase access to care while still delivering empirically-supported
treatment. Such an approach could increase access to mental health
professionals for those in rural areas, facilitate treatment for those
of limited mobility, and increase patient confidentiality (that is,
by engaging in treatment from home clients do not ’risk being
seen at mental health clinics) and privacy (for example, a degree
of visual anonymity). The widespread availability of the Internet
makes this type of intervention feasible and worth consideration.
Recent systematic reviews of computer- and Internet-based treat-
ment for mental health problems suggest largely that these types of
treatment are more effective than a waiting list control and equally
effective as face-to-face psychotherapy in treating anxiety and de-
pression symptoms (Spek 2007;Bee 2008;Cuijpers 2009;Reger
2009;Cuijpers 2010).
How the intervention might work
Therapist-supported ICBT should work to treat anxiety in the
same manner as conventional face-to-face CBT. The underlying
principles of CBT posit that psychopathology, or emotional dis-
turbances, are the result of cognitive distortions and maladaptive
7Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
behaviour. Whereas there are hypotheses about the relative impor-
tance of cognitive and behavioural techniques, as well as sugges-
tions that the strong collaborative working relationship between
the therapist and client are key to the success of CBT, the ex-
act mechanisms of action in CBT are not yet well understood
(Olatunji 2010). It is thought that disorder-specific symptoms de-
velop as a result of a particular pattern of dysfunctional cogni-
tions in combination with a specific set of behaviours that serve
to exacerbate these dysfunctional cognitions further (Beck 2005).
As such, CBT works to improve symptoms by treating these mal-
adaptive cognitions and behaviours.
In essence, cognitive techniques and behaviour modification
strategies are used to identify, evaluate, and challenge underlying
maladaptive thoughts and beliefs. As an example , it is thought that
catastrophic thoughts about the outcomes of experiencing arousal-
related physiological sensations, as well as inaccurate predictions
about the probability of these dangerous outcomes, and avoid-
ance of situations that may induce these sensations contribute to
the development and maintenance of PD (Clark 1986;Barlow
1988). Accordingly, CBT for panic uses cognitive restructuring
techniques to teach individuals to identify and challenge their mal-
adaptive cognitions and beliefs. This is combined with the use of
gradual, repeated exposure to feared sensations to help individu-
als revise their perceptions of threat and reduce their fear of these
arousal-related physiological sensations (Landon 2004). A similar
description of the CBT model could be provided for the other
anxiety disorders (for example, social phobia) (Heimberg 2002).
Whereas the underlying cognitive and behavioural principles are
evident in the CBT interventions for each of the anxiety disorders,
current forms of CBT also target core components of a particular
disorder and, as such, specific models of CBT now exist for each
disorder, which modify and adapt CBT principles to fit disorder-
specific symptoms (for example, specific phobia (Ost 1997); OCD
(Salkovskis 1985;Foa 2010); PD (Clark 1986;Casey 2004); so-
cial phobia (Heimberg 2002); GAD (Dugas 2007); PTSD (Ehlers
2000).
ICBT therapists would be expected to draw on these models in
the same manner as face-to-face CBT therapists. Typically, ICBT
involves the client following a written treatment program avail-
able on the Internet in conjunction with receiving therapist sup-
port, either via telephone calls, texts, or e-mail (Andersson 2006).
The intervention involves content that mimics that of face-to-
face CBT, therapist-client contact (albeit through non-traditional
means), and the client engaging in further ’homework’ outside of
the session. As such, we anticipated that ICBT will work in the
same way and as well as traditional face-to-face CBT.
Why it is important to do this review
Recently, research into ICBT has elicited considerable inter-
est from within the scientific and clinical communities. With
advances in modern communication technologies and their
widespread availability, this type of treatment is quickly becom-
ing a more realistic option. These advances have come at a time
when long waiting lists and a lack of treatment availability stand
in stark contrast to the growing emphasis on the importance of
mental health and provision of evidence-based treatments. A de-
sire to pursue Internet treatment as a viable option to increase
access to treatment is growing. The importance of ensuring that
the decision to promote such treatment is grounded firmly in high
quality evidence is therefore paramount.
The present review asked whether therapist-supported ICBT is ef-
ficacious in treating anxiety, and if it is as efficacious as face-to-face
CBT. Past meta-analyses have reviewed the efficacy of ICBT for
anxiety symptoms (Spek 2007). A number of reviews that have in-
cluded ICBT have looked more broadly, however, at health prob-
lems in general (Barak 2008;Bee 2008) or all computer-based in-
terventions (Cuijpers 2009;Reger 2009;Andrews 2010). More-
over,many of the se reviewshave not focused on the role of therapist
involvement (for example, Cuijpers 2009;Reger 2009;Andrews
2010). Ultimately,as the field of ICBT is growing quickly, an up-
dated review on therapist-supported ICBT is needed. The findings
of this review will be helpful in guiding the path of future research
in this field away from continued replication of established find-
ings and toward addressing gaps in the literature and considering
the next steps in ICBT implementation.
There is a Cochrane Review on media-delivered CBT and be-
havioural therapy (BT) (self-help) for anxiety disorders (Mayo-
Wilson 2013). Mayo-Wilson’s review answers questions about the
efficacy of delivering CBT to clients in non-traditional formats,
including via the Internet. In the protocol of their review, Mayo-
Wilson specified that they would not include studies with therapist
contact. With a post-protocol change, they revised their review to
include studies that involved therapist contact with the qualifier
that the interventions must be able to be delivered stand-alone
without therapist contact. With this in mind, the focus of their
review remains largely on self-help therapies in which therapist in-
volvement is not necessary and treatment is largely client-driven.
Mayo-Wilson did not conduct analyses separating out those in-
terventions with and without therapist contact. As such, a meta-
analysis with a particular emphasis on the efficacy of the rapist-sup-
ported ICBT is needed, particularly as at this point there remains
conflicting evidence of the comparable efficacy of self-help and
therapist-supported interventions (for example, Spek 2007;Titov
2008c;Berger 2011). The present review considered the specific
efficacy of therapist-supported ICBT in comparison to each of a
waiting list control (that is, no treatment), traditional face-to-face
CBT, and self-help interventions and as such will fill a gap in the
literature and answer current calls for research in this area (Reger
2009). The protocol for the present review can be found in the
Cochrane Library (Olthuis 2011).
8Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
O B J E C T I V E S
To assess the effects of therapist-supported ICBT on remission of
anxiety disorder diagnosis and reduction of anxiety symptoms in
adults as compared to waiting list control, unguided CBT, or face-
to-face CBT. Effects of treatment on quality of life and patient
satisfaction with the intervention were also assessed.
M E T H O D S
Criteria for considering studies for this review
Types of studies
We included parallel group randomised controlled trials (RCTs),
cross-over, and cluster randomised trials.
Types of participants
Participant characteristics
We includedstudies of adults (over 18 years of age; no upper limit).
Diagnosis
Participants with a primary diagnosis of an anxiety disorder ac-
cording to the DSM-III (APA 1980), DSM-III-R (APA 1987),
DSM-IV (APA 1994), DSM-IV-TR (APA 2000), ICD-9 (WHO
1979) or ICD-10 (WHO 1999) diagnostic criteria.
We included studies that focused on or adequately reported sub-
group information for any of the following anxiety disorders: panic
disorder (PD) with or without agoraphobia, agoraphobia without
a history of panic, social phobia (social anxiety disorder), post-
traumatic stress disorder (PTSD), acute stress disorder, obsessive
compulsive disorder (OCD), specific phobia, generalized anxiety
disorder (GAD), and anxiety disorder not otherwise specified. In-
cluded studies used diagnoses determined using a validated diag-
nostic instrument, for example, the Structured Clinical Interview
for DSM-IV-TR Axis I Disorders (SCID-I) (First 2002).
Setting
We included studies in which treatment entailed participants en-
gaging in the treatment from their homes and therapists located
at primary care settings, university laboratories, community men-
tal health clinics, or private practice clinics. Participants could be
treatment-seeking community members responding to media ad-
vertisements for study participation or they could be referred to
the study by a health professional.
Co-morbidities
We included studies of participants with co-morbid diagnoses (for
example, major depressive disorder, substance abuse) only if they
had been diagnosed with a primary anxiety disorder. We did not
include studies of participants reporting anxiety symptoms that
did not meet criteria for an anxiety disorder (for example, partici-
pants with a clinical presentation of major depressive disorder who
reported subthreshold anxiety symptoms or participants scoring
high on measures of anxiety symptoms but who were not assessed
for a DSM diagnosis).
Types of interventions
Experimental interventions
Cognitive behavioural therapies
We included studies that investigated the efficacy of a thera-
pist-supported Internet cognitive behavioural therapy (CBT), be-
havioural therapy (BT), or cognitive therapy (CT) intervention
for anxiety, defined as the following.
BT interventions must have been designed to change the
behaviours that result from maladaptive anxiety-related
cognitions (we included interventions including, but not limited
to, exposure, desensitization, and behavioural experiments).
CT must have been focused on elements of cognitive
restructuring of irrational or maladaptive anxiety-related
cognitions.
CBT interventions consisted of some combination of the
elements of CT and BT.
Whereas psychoeducation often is an important part of CBT, we
did not consider psychoeducation alone to be a sufficient CBT
intervention unless it included some of the other treatment com-
ponents described here.
Internet interventions
To be considered an Internet intervention, CBT must have been
delivered over the Internet through the use of web pages or e-
mail, or both. Crucially, Internet interventions must have included
therapist support but this interaction could not be face-to-face.
However, we included interventions that involved an initial face-
to-face intake or interview session or an initial session to orient
clients to the Internet delivery method or to engage in treatment
planning, or a combination of these. Thus, therapist support must
have occurred via e-mail or the telephone, or both. Including only
interventions that could be delivered entirely by distance methods
reflected a primary motive for conducting this review, to find ways
to increase access to treatment for those who may not be able to
visit provider centres. While it was possible that Internet-based
interventions that provided some support in a face-to-face setting
9Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
could be just as effectively restructured to be delivered completely
by distance, it was more rigorous to include only studies that pro-
vided evidence specifically on the efficacy of Internet CBT deliv-
ered completely via distance methods. We did not select interven-
tions based on their length, or the number or duration of sessions.
Comparator interventions
1. Waiting list, attention, information, or online discussion
group only control condition (no intervention for participants
beyond weekly status monitoring by research personnel or
accessing online non-treatment related disease information or
discussion groups)
2. Unguided CBT (i.e., self-help CBT with no therapist
support)
3. Conventional face-to-face CBT interventions (including
individual or group CBT delivered in a traditional face-to-face
format)
Types of outcome measures
Primary outcomes
1. Efficacy of therapist-supported ICBT in leading to
clinically important improvement in anxiety as determined by a
diagnostic interview, for example, the SCID-I (First 2002) or the
Anxiety Disorders Interview Schedule (ADIS-IV) (DiNardo
1994) or a defined cut-off on a validated scale, for example, the
Yale Brown Obsessive Compulsive Scale (YBOCS) (Goodman
1989). In case the Clinical Global Impression scale change or
improvement items (CGI) (Guy 1976) were used, we employed
a score of 1 = ’very much’ or 2 = ’much improved’ to indicate
clinically important improvement.
2. Efficacy of therapist-supported ICBT in leading to
reduction in anxiety symptom severity measured by scores on a
validated, observer-rated instrument, for example, the Hamilton
Anxiety Rating Scale (Hamilton 1959), or a validated self-report
measure of: (a) disorder-specific symptoms, for example, the
Social Phobia Scale (SPS) (Mattick 1998), and (b) anxiety
symptoms in general, for example, the Beck Anxiety Inventory
(BAI) (Beck 1991).
Secondary outcomes
1. Quality of life as assessed by either measures of quality of
life, for example, the Quality of Life Inventory (QOLI) (Frisch
1992), or measures of disability, for example the Sheehan
Disability Scales (SDS) (Leon 1997) as increasing disability
entails decreased quality of life. While research suggests that
quality of life and disability are distinct but somewhat
overlapping constructs (Hambrick 2003), quality of life
measures have not often been conceptually or operationally
distinguished from measures of disability, resulting in
considerable overlap amongst indices of quality of life and
disability (Mogotsi 2000). With this in mind, we anticipated an
overlapping conceptualization of these two constructs in the
included studies and included both types of measures within the
meta-analysis in order to capture all possible information about
treatment outcome related to quality of life.
2. Participant satisfaction with the intervention. Participant
satisfaction tends to be measured uniquely across different
studies using a mix of qualitative and quantitative indices. In
anticipation of this, we evaluated participants’ satisfaction with
the intervention of interest as compared to the comparator
interventions in a qualitative manner.
3. Adverse events, in whatever manner reported by study
authors.
Timing of outcome assessment
We performed separate analyses based on different periods of as-
sessment: immediately post-treatment and at one follow-up pe-
riod at least six months post-treatment but not more than one
year. When studies reported more than one follow-up assessment
point, we used the longest follow-up period so as to provide the
best estimate of the long-term outcomes of the intervention.
Hierarchy of outcome measures
For primary outcomes, separate meta-analyses were conducted for
the two outcomes. The clinically important improvement in anx-
iety outcome measures were selected according to the following
hierarchy, based on availability in a particular study: (1) diagnostic
interview, (2) cut-off on a validated scale, (3) CGI scores. For re-
duction in anxiety symptom severity, the outcomes of available ob-
server-rated and self-report measures were statistically combined
and a mean score was created across the measures within a partic-
ular study. Measures of variance for this mean score were created
by combining standard deviations across studies according to the
method described by Borenstein 2009. This method requires that
the correlation between two measures be known; as such, in the
case that this correlation was not known, the measures with better
psychometric properties were included in the analysis.
For secondary outcomes, quality of life outcome measures were
treated in the same way as anxiety symptom severity measures.
Due to the qualitative nature of the other secondary outcome, par-
ticipant satisfaction with the intervention, a hierarchy of outcome
measures was not required.
Search methods for identification of studies
We used several methods to identify both published and unpub-
lished studies for possible inclusion in this review (see below). We
did not restrict studies to those reported in any particular language;
however, we conducted searches in English and initiated contact
with authors in English.
10Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
Electronic searches
The Cochrane, Depression, Anxiety and Neurosis Review
Group’s Specialised Register (CCDANCTR)
The Cochrane Depression, Anxiety and Neurosis Group (CC-
DAN) maintains two clinical trials registers at their editorial base
in Bristol, UK, a references register and a studies-based register.
The CCDANCTR-References Register contains over 37,000 re-
ports of RCTs in depression, anxiety, and neurosis. Approximately
60% of these references have been tagged to individual, coded tri-
als. The coded trials are held in the CCDANCTR-Studies Regis-
ter and records are linked between the two registers through the
use of unique Study ID tags. Coding of trials is based on the
EU-Psi coding manual. Please contact the CCDAN Trials Search
Co-ordinator for further details. Reports of trials for inclusion in
the Group’s registers are collated from routine (weekly), generic
searches of MEDLINE (1950 to date), EMBASE (1974 to date)
and PsycINFO (1967 to date); quarterly searches of the Cochrane
Central Register of Controlled Trials (CENTRAL), and review-
specific searches of additional databases. Reports of trials are also
sourced from international trial registers via the World Health
Organisation (WHO International Clinical Trials Registry Plat-
form (ICTRP), ClinicalTrials.gov, dr ug companies, and the hand-
searching of key journals, conference proceedings, and other (non-
Cochrane) systematic reviews and meta-analyses.
Details of CCDAN’s generic search strategies can be found on the
Group‘s website.
We searched the CCDAN Specialised Registers to 12 April 2013
and the results from this search were fully incorporated in the
present review. Additionally, prior to publication, CCDAN’s Tri-
als Search Co-ordinator performed a precise update search of the
CCDANCTR Registers in September 2014 (Appendix 1). The
results were screened at the CCDAN’s editorial base and by the
first author and relevant studies were placed in awaiting classifica-
tion or ongoing (as appropriate). These studies will be fully incor-
porated in a timely, future update of this review.
CCDANCTR-Studies
We searched the CCDANCTR-Studies Register using the follow-
ing search strategy:
1. Condition = (anxiety or *phobi* or PTSD or post-trauma* or
“post trauma*” or posttrauma* or “stress disorder” or panic or
OCD or obsess* or compulsi* or GAD)
2. Intervention = (CBT or cognitive or behavio* or *therap* or
treatment or intervention or training or counsel*)
3. Age Group = (adult or aged or unclear or “not stated”)
4. Free-Text = (computer* or distance* or remote or tele* or Inter-
net* or web* or WWW or phone or mobile or e-mail* or email*
or online* or on-line or videoconferenc* or video-conferenc* or
“chat room*” or “instant messaging” or iCBT)
5. (1 and 2 and 3 and 4)
CCDANCTR-References
We searched the CCDANCTR-References Register to identify
additional untagged or uncoded references using the following
strategy:
1. (anxiety or *phobi* or PTSD or post-trauma* or “posttrauma*”
or posttrauma* or (stress and disorder*) or panic or OCD or ob-
sess* or compulsi* or GAD):ti,ab,kw
2. (therap* or train*):ti,ab
3. (psychotherap* or cognitive or behavio* or CBT):ti,ab,kw
4. (acceptance* or assertive* or brief* or commitment* or exposure
or group or implosive or “problem solving” or problem-solving or
“solution focused” or solution-focused or schema):ti,ab,kw
5. (CBT or cognitive or behavio* or “contingency management”
or “functional analys*” or mindfulness* or “mind training” or psy-
choeducat* or relaxation or “role play*”):ti,ab,kw
6. ((2 or 3) and 4) or 5
7. (computer* or distance* or remote or tele* or Internet* or web*
or WWW or phone or mobile or e-mail* or email* or online* or
on-line or videoconferenc* or video-conferenc* or “chat room*”
or “instant messaging” or iCBT):ti,ab,kw
8. 1 and 6 and 7
Searching other resources
Reference lists
We examined the reference lists of previous related meta-analyses
(Spek 2007;Bee 2008;Cuijpers 2009;Reger 2009;Andrews 2010;
Cuijpers 2010) and of articles selected for inclusion in the present
review.
Personal contacts and correspondence
We contacted experts in the field, including principal authors of
RCTs in the field of ICBT for anxiety, via e-mail and asked them
if they were aware of any further studies which meet the present
review’s inclusion criteria.
Unpublished studies
In order to search for unpublished studies, we searched
international trial registries including via the WHO IC-
TRP (http://apps.who.int/trialsearch/) and ClinicalTrials.gov (
www.clinicaltrials.gov) in June 2013.
Data collection and analysis
Selection of studies
In collaboration with the CCDAN Trials Search Co-ordinator,one
review author (JVO) conducted searches of electronic databases
11Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
and reference lists and contacted authors in order to locate poten-
tial trials to be included in the review. Two review authors (JVO
and KMB) independently assessed the titles and abstracts of the
resulting lists of studies for relevance. We then obtained full ar-
ticles for potentially relevant abstracts. Both review authors inde-
pendently assessed the identified trials to determine eligibility as
outlined in Criteria for considering studies for this review. We col-
lated and compared assessments. In the case of disagreement with
respect to trial eligibility, we made the final decision by discus-
sion and consensus, if necessary with the involvement of another
member of the review group (MCW or SHS, or both).
Data extraction and management
We independently extracted data from the included studies re-
garding methodology and treatment outcomes, and recorded the
data using a data extraction spreadsheet designed by one of the
review authors (JVO). If the included trials did not provide com-
plete information (for example, details of dropout, group means
and standard deviations), we contacted the primary investigator
by e-mail to attempt to obtain unreported data to permit an in-
tention-to-treat (ITT) analysis. We contacted other investigators
as needed.
Two review authors (JVO and KMB) independently extracted the
following data from each trial report:
1. description of trial, including primary researcher and year
of publication;
2. characteristics of trial methodology, including the
diagnostic criteria employed, participant inclusion and exclusion
criteria, the screening instrument(s) used, the inclusion or
exclusion of co-morbidity, the receipt of other interventions
simultaneously, and the number of centres involved;
3. characteristics of participants, including age, gender,
primary diagnosis, any co-morbid diagnoses, and duration of
primary symptoms;
4. characteristics of the intervention (for both the
experimental and comparator interventions), including
intervention classification (i.e., CBT, BT, CT), content and
components (e.g., psychoeducation, relaxation training,
exposure, cognitive restructuring), method of delivery of
therapist support (e.g., telephone, e-mail), duration, amount of
therapist and experimenter contact, and number of participants
randomised to each intervention; and
5. outcome measures employed, as listed in Types of outcome
measures, as well as the dropout rates for participants in each
treatment condition and whether the data reflected intention-to-
treat (ITT) analyses with last observation carried forward
(LOCF) or another method.
We subsequently recorded data in RevMan 5.3 data tables
(RevMan 2014).
Main planned comparisons
We planned to compare each of the outcomes of interest, at post-
treatment and 6 to 12 month follow-up, for each of the following
comparisons:
1. therapist-supported ICBT versus waiting list, attention,
information, or online discussion group only control,
2. therapist-supported ICBT versus unguided CBT, and
3. therapist-supported ICBT versus face-to-face CBT.
Assessment of risk of bias in included studies
We assessed the risk of bias in each included study using the
Cochrane Collaboration’s ’risk of bias’ tool (Higgins 2011a). We
assessed the following six areas for risk of bias.
1. Sequence generation: was the allocation sequence of
participants adequately randomised?
2. Allocation concealment: was the allocation sequence
adequately concealed from participants as well as those involved
in the enrolment and assignment of participants?
3. Blinding: were participants, study personnel, and those
assessing outcomes kept unaware of participants’ allocation to a
study condition throughout the course of the investigation?
4. Incomplete outcome data: were there incomplete data for
the main or secondary outcomes (e.g., due to attrition)? Were
incomplete data adequately addressed?
5. Selective reporting: was the study free of suggestions of
selective reporting of outcomes (e.g., reporting of a subset of
outcomes on the basis of the results)?
6. Other potential threats to bias: was the study free of any
other problems (e.g., early stopping, baseline imbalance, cross-
over trials) that could have introduced bias?
We did not assess risk of bias related to therapist experience and
qualifications. Evidence in the field as to the impact of therapist
experience on treatment outcomes remains mixed (for example,
Hahlweg 2001;Andersson 2012;Norton 2014), as such, it would
be inappropriate to impose bias on a study based on a characteristic
we are unsure would actually introduce bias. In addition, we did
not assess risk of bias related to therapist allegiance. This was
because: (a) all studies investigated CBT, and (b) it was impossible
to know if researchers were allied with a particular type of delivery
method.
Two review authors (JVO and KMB) independently assessed risk
of bias for each included study. We resolved disagreements by
consensus and discussion with a third review author (MCW or
SHS) where necessary. If further information about a particular
trial was required to assess its risk of bias, we contacted the pr imary
investigator of the relevant study. We created ’risk of bias’ tables
describing the information outlined above, as reported in each
study. These tables also include a judgement on the risk of bias,
made by the review authors for each of the six areas, based on the
following three categories: (1) low risk of bias, (2) high risk of bias,
and (3) unclear or unknown risk of bias.
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Measures of treatment effect
Dichotomous outcomes
We analysed our only dichotomous outcome, clinically important
improvement in anxiety (yes or no) (as measured by no longer
meeting diagnostic criteria on a diagnostic interview, no longer
meeting a designated cut-off on a validated scale, or meeting the
criteria for very much or much improved on the CGI) using risk
ratios (RRs) and 95% confidence intervals (CIs) within studies.
Continuous outcomes
As most studies that were selecte d for inclusion used different mea-
sures to assess sufficiently similar constructs, we compared con-
tinuous outcomes (that is, general and disorder-specific anxiety
symptoms, quality of life) by calculating the standardized mean
difference (SMD) and its 95% CI. However, when all of the stud-
ies within a meta-analysis used the same measure to assess an out-
come (for example, if all studies within a meta-analysis used the
BAI to assess general anxiety symptoms), we compared continuous
outcomes by calculating the mean difference (MD) to facilitate
the interpretation of the clinical relevance of the findings.
Most included studies used more than one measure to assess each
of the continuous outcomes. Thus, a mean score was created across
the measures included within each study. Measures of variance for
this mean score were created by combining standard deviations
across studies according to the method described by Borenstein
2009. This method requires that the correlation between two mea-
sures be known; as such, on the rare occasion when this correlation
was not known and could not be identified in prior literature the
measure in question was excluded from analyses. This occurred in
four instances (Klein 2006,Richards 2006, and Kiropoulos 2008
for the Body Vigilance Scale; Andersson 2009 for the Fear Survey
Schedule III).
To combine measures of quality of life and disability into one
outcome, we reversed the scores of the disability measures (that is,
by subtracting mean scores from the measure total scores) to align
them with the quality of life measures.
Endpoint versus change data
Weanticipated that we might encounter some studies that reported
analyses based on changes from baseline and other studies that
reported analyses based on final values. We planned to present
the two types of analysis results in separate subgroups to avoid
confusion for readers and, where appropriate, to combine both
types of scores in the final results. Despite these plans, none of the
included studies reported change data so we used endpoint data
in all meta-analyses.
Skewed data
We dealt with skewed data according to the guidelines in the
Cochrane Handbook for Systematic Reviews of Interventions (Higgins
2011a) and Higgins 2008. In order to conduct the final analy-
sis, transformed or untransformed data had to be obtained for all
studies because log-transformed and untransformed data cannot
be combined in meta-analyses (Higgins 2011a). In the case that
a limited number of studies included in one meta-analysis pre-
sented log-transformed data, we back-transformed these data and
included untransformed data in the meta-analysis. We then con-
ducted a sensitivity analysis excluding any studies that presented
transformed data.
Unit of analysis issues
Parallel group randomised controlled trials (RCTs)
In some parallel group RCTs, participants randomly assigned to
a waiting list, attention, information, or online discussion group
only control were permitted to pursue the active treatment after
their period on the waiting list was complete. To analyse dichoto-
mous and continuous data for these trials, we only included data
from participants before they crossed over to their second treat-
ment condition; in other words, only data from the original com-
parison (waiting list, attention, information, or online discussion
group only control versus therapist-supported ICBT) was used in
the meta-analyses.
Cross-over trials
When included studies were cross-over trials, we planned to in-
clude only data from the first phase of the trial.
Cluster randomised trials
When cluster randomised trials had accounted for clustering
within their analyses (through the use of multilevel modelling or
general estimating equations, for example) we planned to include
data directly in the meta-analyses. For studies that failed to ap-
propriately account for clustering, we planned to impute the data
based on the number of clusters reported in each intervention
group, the size of each cluster, summary statistics, and an estimate
of intracluster correlation. We also planned to exclude cluster trials
with a high risk of bias (that is, where clustering was not accounted
for in analyses) from sensitivity analyses.
Multiple intervention arms
When multiple intervention arms met our inclusion criteria, we
planned to combine eligible groups to create a pair-wise compari-
son following the procedure outlined in the Cochrane Handbookf or
Systematic Reviews of Interventions (Higgins 2011a). We planned
13Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
to conduct sensitivity analyses excluding any studies with multi-
ple intervention arms that did not report all intervention compar-
isons.
Dealing with missing data
We used data from ITT analyses whenever they were reported by
study authors. In 21 studies, authors employed a LOCF method
to address missing data with the assumption that participants who
were missing data following randomisation (that is, dropouts) did
not respond to treatment. Of the remaining studies, one study used
multiple imputation methods to create ITT data (van Ballegooijen
2013). Seven studies used a mixed effects models approach in an
ITT approach to deal with missing data (Bergstrom 2010;Berger
2011;Hedman 2011;Paxling 2011;Andersson 2012a;Andersson
2012b;Silfvernagel 2012). One study did not include ITT data
(Andersson 2009).
Because included studies did not report individual participant
data, if authors did not provide ITT analyses in their manuscript
we contacted the primary investigator by e-mail to attempt to ob-
tain unreported data to permit an ITT analysis. When we did not
receive responses from study authors we simply included their re-
ported, non-ITT, continuous outcome data in the analysis. This
was the case for one study (Andersson 2009). For dichotomous
outcomes, we were able to impute ITT data by assuming that par-
ticipants who had dropped out did not meet the target event (that
is, clinically important improvement in anxiety). We conducted
sensitivity analyses excluding studies for which ITT data were not
available (either from the published manuscript or from study au-
thors) to determine the extent to which missing data influenced
effect sizes.
If included trials did not provide complete information (that is,
group means, standard deviations, and sample size), we contacted
the primary investigator by e-mail to attempt to obtain unreported
data. We contacted other study investigators as needed. The only
sources for outcome data were the original published report or
author correspondence. If standard deviations were not available
from the authors, we planned to calculate these using other data
reported in the article, including t-values, CIs, and standard errors.
If that was not possible, we planned to impute standard deviations
from other investigations using similar measures and populations.
Assessment of heterogeneity
We tested the extent of statistical heterogeneity in meta-analyses
using the I2statistic (Higgins 2002), which calculates the per-
centage of variability due to heterogeneity rather than chance. Ac-
cording to the guidelines outlined in the Cochrane Handbook for
Systematic Reviews of Interventions, I2values may be interpreted as
follows:
0% to 40% might not be important;
30% to 60% may represent moderate heterogeneity;
50% to 90% may represent substantial heterogeneity; and
75% to 100% represents considerable heterogeneity
(Higgins 2011a).
We interpreted the importance of these I2values in consideration
of the magnitude and direction of effects and the strength of evi-
dence for heterogeneity (as indexed by the P value from the Chi2
test). If there was evidence of heterogeneity, we first re-checked the
data for accuracy. We considered sources of heterogeneity accord-
ing to the pre-specified subgroup and sensitivity analyses listed in
Subgroup analysis and investigation of heterogeneity.
Assessment of reporting biases
Where there were sufficient numbers of trials to make such a plot
meaningful (that is, at least 10 included studies (Higgins 2011a))
we constructed funnel plots to determine the possible influence of
publication bias. We planned to enhance fu nnel plots with contour
lines delineating areas of statistical significance (as suggested by
Peters 2008) to assist in the differentiation of asymmetry due to
publication bias or other causes.
Data synthesis
We combined data using an inverse-variance random-effects
model due to expected variation in the characteristics of the in-
terventions investigated and participant populations. We com-
bined dichotomous outcome measures by computing a pooled
risk ratio (RR) and 95% CI. We combined continuous outcomes
when means and standard deviations were available. When suf-
ficiently similar continuous outcomes were measured differently
across studies we calculated an overall standardized mean differ-
ence (SMD) and 95% CI. However, as indicated previously, when
outcomes were measured similarly across studies we used a mean
difference method. We used the RevMan 5.3 software for data
synthesis.
Subgroup analysis and investigation of heterogeneity
We conducted subgroup analyses but interpreted these with cau-
tion due to the risk of false positive conclusions. We planned to
perform the following subgroup analyses:
1. gender of participants;
2. type of anxiety disorder (i.e., PD with or without
agoraphobia, agoraphobia without a history of panic, social
phobia (social anxiety disorder), PTSD, acute stress disorder,
OCD, specific phobia, GAD, and anxiety disorder not otherwise
specified);
3. amount of therapist contact, designated as low (90 min or
less), medium (91 to 299 min), or high (300 min or more);
4. type of CBT (i.e., BT, CT, or CBT); and
5. research group (i.e., the laboratory from which the study
was generated).
14Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
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We were not able to conduct a subgroup analysis based on gender
of participants as none of the included studies distinguished out-
comes based on this participant variable. We also were not able
to conduct a subgroup analysis based on type of CBT. Only one
study (Andersson 2009) had a stronger focus on BT, as compared
to CT or CBT, and no studies examined a CT only intervention.
For the final subgroup analysis by research group, three research
groups were identified: a group in Sweden, and two distinct groups
in Australia.
Sensitivity analysis
Weconducted sensitivity analyses to determine the extent to which
observed pooled effect sizes depend on the quality of the design
characteristics of studies. We planned to conduct the following
sensitivity analyses:
1. exclusion of studies with a designation of high risk of bias
for one or more of the categories as outlined in Assessment of
risk of bias in included studies;
2. exclusion of cluster randomised trials where clustering was
not appropriately accounted for in analysis;
3. exclusion of studies with multiple intervention arms with
selective reporting of intervention comparisons;
4. exclusion of studies with a somewhat more active waiting
list control condition (i.e., attention, information, or online
discussion group only control)
5. exclusion of studies with imputed standard deviations for
continuous outcomes;
6. exclusion of studies with back transformed data for
continuous outcomes;
7. exclusion of studies not reporting: (a) dichotomous, and (b)
continuous outcomes according to the ITT principle;
8. exclusion of studies with continuous outcomes analysed
using LOCF; and
9. assuming treatment dropouts were responders for
dichotomous outcomes.
Summary of findings
Summary of findings tables were created to present the main find-
ings of the review. We imported meta-analytic data from RevMan
into GRADEprofiler version 3.6 to create summary of findings
tables for each of the three most clinically relevant comparisons:
ICBT with therapist support versus waiting list control, ICBTwith
therapist support versus unguided ICBT, and ICBT with thera-
pist support versus face-to-face CBT. The summary of findings
tables present meta-analytic outcomes for each of the continuous
and dichotomous outcomes at post-treatment and summarize the
number of studies and participants included in each analysis. In
addition, GRADEprofiler allowed us to rate the quality of the evi-
dence for each outcome for each comparison considering: (a) risk
of bias, (b) inconsistency, (c) indirectness, (d) imprecision, and(e)
publication bias.
R E S U L T S
Description of studies
See Characteristics of included studies;Characteristics of excluded
studies
Results of the search
The electronic search of databases (conducted April 2013), yielded
826 citations for consideration for inclusion in the review, includ-
ing manuscripts in peer-reviewed journals, conference abstracts,
and clinical trial registrations. Employing secondary search meth-
ods, including searching clinical trial registries, contacting experts
in the field, and searching the reference lists of eligible studies,
resulted in another 471 citations for consideration. After de-du-
plication and following a brief screening of thetitles and abstracts,
212 were retrieved for a more detailed evaluation of eligibility.
One hundred and fifty-one studies were subsequently excluded for
failing to meet our inclusion criteria. The PRISMA flow diagram
shown in Figure 1 outlines the study selection process and broad
reasons for exclusion. Studies were excluded if: (a) participants did
not meet diagnostic criteria for an anxiety disorder, as assessed by
study authors (population), (b) the intervention of interest was not
ICBT, did not involve a therapist, or included too much face-to-
face therapist contact (intervention), (c) the comparator was not
appropriate given our selection criteria (comparator), (d) the trial
was not randomised or did not use adequate diagnostic measures
(methods), or (e) the trial was ongoing (ongoing).
15Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
Figure 1. PRISMA diagram of the search process.
16Therapist-supported Internet cognitive behavioural therapy for anxiety disorders in adults (Review)
Copyright © 2015 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
After accounting for duplicate reports of the same trial, 30 studies
were eligible for inclusion in the meta-analyses. Seven studies iden-
tified from an updated search in September 2014 have been added
to studies awaiting classification (Andersson 2013;Berger 2014;
Ivarsson 2014;Newby 2013), as have seven studies which were