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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
PAXonline: A Randomized Controlled Trial Assessing the Efficacy of an Internet-Based Cognitive Behavior Intervention for Panic Disorder
Scientific title
PAXonline: A Randomized Controlled Trial Comparing the Efficacy of an Internet-Based Cognitive Behavior Intervention, delivered with or without assistance from a therapist, to waiting-list in Romanian adults with Panic Disorder
Secondary ID [1] 284620 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Panic Disorder 291929 0
Condition category
Condition code
Mental Health 292283 292283 0 0

Study type
Description of intervention(s) / exposure
The PAXonline Program for Panic Disorder is an internet-based treatment of twelve weeks, which consists of cognitive-behavioral therapy modules, delivered with or without assistance from a therapist .

The Panic Disorder Program contains 16 modules which address important cognitive behavioral psychotherapy elements such as: psychoeducation on the disorder and means of intervention (Module 1. Understand what’s happening to you and Module 2. Understand what you have to do), techniques for decreasing neurophysiologic hyper-activation (module for breathing regulation, autogenic training relaxation, physical exercise), techniques for cognitive restructuring (attention modification and conscious and unconscious dysfunctional beliefs modification), exposure techniques (interoceptive and exteroceptive), skills training (problem solving) and positive emotions training (positive psychology), behavioral activation and cognitive restructuring of possible comorbid depression symptoms and relapse prevention.

Each module can be completed in 30-40 minutes and the participants are provided with a recommended timetable (one or two modules per week, depending on the complexity of the content and the homework assignments).

In this trial Romanian adults with Panic disorder will be randomly allocated to one of three groups:
Group 1: Guided panic disorder program. Participants in this group will complete the panic disorder treatment program with support from a therapist (weekly emails and regular 15 minutes Skype sessions; in total, there will be 9 Skype sessions).
Group 2: Self-guided panic disorder program. Participants in this group will complete the treatment program in a self-guided format, that is, without support from a therapist.
Group 3: Wait-list control group.

The modules and the entire therapeutic environment is carefully designed in order to catalyze the psychotherapeutic process in the mind of the patients.

The program contains also certain techniques to improve adherence and compliance with the treatment e.g. rewards after module completion (short movies that induce positive emotions), The daily thought, which is sent through e-mail every other 5 days etc.

The participants adherence is carefully monitored through several applications that register: overall usage time, the modules completed and the time spent on each module and each module component. There is also an application, the participants use to report the completion of homework assignments for each module.
Intervention code [1] 289401 0
Treatment: Other
Intervention code [2] 289402 0
Comparator / control treatment
The comparator is a waiting list group.
This group receive their choice of the two treatment options once the other groups have completed the program (after 12 weeks).
Control group

Primary outcome [1] 292148 0
Symptoms and severity of panic disorder are measured by the Panic Disorder Severity Rating Scale - Self Report (PDSS-SR)
Timepoint [1] 292148 0
Administered at pre-treatment, every two weeks after intervention commencement, at post-treatment, and at follow-up: months 1, 3, 6, 12
Primary outcome [2] 292149 0
The Agoraphobic Cognitions Questionnaire
Timepoint [2] 292149 0
At pre-treatment, 6 weeks after intervention commencement, post-treatment, and follow-up: months 1, 3, 6, 12
Primary outcome [3] 292150 0
The Body Sensations Questionnaire
Timepoint [3] 292150 0
At pre-treatment, 6 weeks after intervention commencement, post-treatment, and follow-up: months 1, 3, 6, 12
Secondary outcome [1] 308297 0
Symptoms and severity of low mood/depression are measured by the Patient Health Questionnaire-9 (PHQ-9)
Timepoint [1] 308297 0
At pre-treatment, 6 weeks after intervention commencement, post-treatment, and follow-up: months 1, 3, 6, 12
Secondary outcome [2] 308298 0
The Work and Social Adjustment Scale
Timepoint [2] 308298 0
At pre-treatment, 6 weeks after intervention commencement, post-treatment, and follow-up: months 1, 3, 6, 12
Secondary outcome [3] 308299 0
Working alliance is measured by the Working Alliance Inventory Short Revised (WAI-SR)
Timepoint [3] 308299 0
Administered at 3 weeks and 6 weeks
Secondary outcome [4] 308302 0
Psychiatric Diagnostic and Screening Questionnaire (PDSQ)
Timepoint [4] 308302 0
At pre-treatment, 6 weeks after intervention commencement, post-treatment
Secondary outcome [5] 308303 0
System Usability Scale
Timepoint [5] 308303 0
Administered at 3 and 6 weeks
Secondary outcome [6] 308304 0
Credibility/ Expectancy Questionnaire (CEQ)
Timepoint [6] 308304 0
Administered at 3 and 6 weeks
Secondary outcome [7] 308305 0
A modified version of Body vigilance scale
Timepoint [7] 308305 0
Administered at pre-treatment, 6 weeks after the intervention commencement, and at post-treatment.
Secondary outcome [8] 308306 0
Panic Attack Cognition Questionnaire (PACQ)
Timepoint [8] 308306 0
Administered pre-treatment, after 6 weeks, and at post-treatment
Secondary outcome [9] 308307 0
SS-5; a 5-item shortened version of the Medical Outcomes Study Social Support Scale (MOS-SSS)
Timepoint [9] 308307 0
at pre-treatment and 6 weeks after intervention commencement
Secondary outcome [10] 315929 0
Dependent personality disorder traits (Scale from OMNI-IV - Personality Disorder Inventory)
Timepoint [10] 315929 0
administered at pre-treatment

Key inclusion criteria
- primary diagnostic of Panic Disorder (confirmed by an experienced clinician through semi-structured clinical interview)
- computer with internet access
- native Romanian speakers, not necessarily from Romania
- no participation in psychological treatment for panic
disorder in the last 3 months.
- no change in medications in the period 3 month prior to this study
Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
presence of:
- severe depression
- substance abuse,
- suicidal ideation or behaviors,
- personality disorders,
- psychotic disorders,
- mental retardation,
- benzodiazepines treatment

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
The first step consists in completing 3 online questionnaires. The first addresses the exclusion criteria, the second identify the panic disorder diagnostic and severity, and the third evaluates other possible comorbidities.

The second step consists in a semi-structured clinical interview conducted through Skype or telephone by a specialist.

If the subject meets all the eligibility criteria, he signs the informed consent document and he is randomly allocated to one of the three groups.

The allocation concealment is performed through the central randomization by a computer. The person in charge with the allocation of subjects to treatment groups is unaware to which group a new subject will be allocated. This person has access only to the data needed to fill out in the computer program the stratification factors used in the process of randomization. The program then automatically allocates the subject to a treatment group by use of an adaptive randomization algorithm. The result or the algorithm can not be influenced by this person.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The allocation to intervention is randomized control trial. The method employed is minimization, based on the dynamic algorithm put forward by Pocock & Simon (1975), using two stratification factors: SEVERITY (3 levels) and CHRONICITY (2 levels) of Panic disorder. The severity factor is based on the score obtained at the pre-treatment PDSS-SR measurement. The chronicity factor is measured in the pre-treatment structured clinical interview as the number of months passed since the Panic Disorder has started.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
The sample size needed to achieve study objectives has been computed using GPower targeting Manova: Repeated measures, within-between interactions and t-tests for independent and dependent means, expecting a large effect size, a power size of .90 and setting alpha at .05. The recommended sample size has been increased to accommodate an attrition rate of 20%. Thus, the study aims to achieve a sample of 120 participants.

We will measure and test if symptoms significantly improve, both statistically and clinically.

The primary analyses to be made will be intention to treat, but there will be also additional analysis just for the treatment completers.

Missing data for ITT approaches can be managed in a number of ways, but we intend to use the more advanced methods which include the use of multiple imputation and maximum-likelihood based methods.

Recruitment status
Active, not recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 6056 0
State/province [1] 6056 0
Country [2] 6057 0
State/province [2] 6057 0
Country [3] 6058 0
State/province [3] 6058 0

Funding & Sponsors
Funding source category [1] 289247 0
Name [1] 289247 0
ACPOR-The Romanian Association for Online Counselling and Psychotherapy
Address [1] 289247 0
18, Piata 14 Iulie Street, Cluj-Napoca
400325, Cluj
Country [1] 289247 0
Funding source category [2] 291667 0
Government body
Name [2] 291667 0
Sciex - Scientific Exchange Programme NMS.CH
Address [2] 291667 0
P.O. Box 607
CH-3000 Berne 9
Country [2] 291667 0
Primary sponsor type
Babes-Bolyai University, School of Psychology and Educational Sciences, Department of Psychology
37, Republicii Street, Cluj-Napoca
400015, Cluj
Secondary sponsor category [1] 287921 0
Name [1] 287921 0
ACPOR-The Romanian Association for Online Counselling and Psychotherapy
Address [1] 287921 0
18, Piata 14 Iulie Street, Cluj-Napoca
400325, Cluj
Country [1] 287921 0

Ethics approval
Ethics application status
Ethics committee name [1] 291016 0
Ethical Review Board of The Center for the Management of Scientific Research, Babes-Bolyai University
Ethics committee address [1] 291016 0
No. 7-9, Universitatii Street, Cluj-Napoca
400091, Cluj
Ethics committee country [1] 291016 0
Date submitted for ethics approval [1] 291016 0
Approval date [1] 291016 0
Ethics approval number [1] 291016 0

Brief summary
The main objective of this study is to test the efficacy of PAXonline, an internet based cognitive-behavioral therapy program, in the treatment of Panic Disorder. Other important aims are identifying the mechanisms of change and patient characteristics for whom this type of therapy is most suited and has the best results.

Two treatment groups will be used, one with therapist guidance and one without, as well as a wait-list control group.

We expect that the guided intervention program will result in superior outcomes to the unguided intervention program. Both treatment groups are presumed to be superior to the wait-list control.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 48498 0
Ms Amalia Ciuca
Address 48498 0
Babes-Bolyai University, School of Psychology and Educational Sciences, Department of Psychology

37, Republicii Street, Cluj-Napoca
400015, Cluj
Country 48498 0
Phone 48498 0
+40 745590576
Fax 48498 0
Email 48498 0
Contact person for public queries
Name 48499 0
Mr Liviu G. Crisan
Address 48499 0
Babes-Bolyai University, School of Psychology and Educational Sciences, Department of Psychology

37, Republicii Street, Cluj-Napoca
400015, Cluj
Country 48499 0
Phone 48499 0
+40 753 529 753
Fax 48499 0
Email 48499 0
Contact person for scientific queries
Name 48500 0
Ms Amalia Ciuca
Address 48500 0
Babes-Bolyai University, School of Psychology and Educational Sciences, Department of Psychology

37, Republicii Street, Cluj-Napoca
400015, Cluj

Country 48500 0
Phone 48500 0
+40 745 590 576
Fax 48500 0
Email 48500 0

No information has been provided regarding IPD availability
How or where can supporting documents be obtained?
Type [1] 386 0
Study protocol
Citation [1] 386 0
Link [1] 386 0
Email [1] 386 0
Other [1] 386 0
Summary results
Have study results been published in a peer-reviewed journal?
Journal publication details
Publication date and citation/details [1] 385 0
Ciuca, A.M., Berger, T., Crisan, L.G., Miclea, M. (2018). Internet-based treatment for panic disorder: A three-arm randomized controlled trial comparing guided (via real-time video sessions) with unguided self-help treatment and a waitlist control. PAXPD study results. Journal of Anxiety Disorders, 56:43-55. doi: 10.1016/j.janxdis.2018.03.009
Publication date and citation/details [2] 387 0
Ciuca, A.M., Berger, T., Miclea, M. (2017). Maria and Andrea: Comparing Positive and Negative Outcome Cases in an Online, Clinician-Guided, Self-Help Intervention for Panic Disorder. Pragmatic Case Studies in Psychotherapy, Volume 13, Module 3, Article 1, pp. 173-216
Other publications
Have study results been made publicly available in another format?
Other publication details
Citation type [1] 390 0
Citation/DOI/link/details [1] 390 0
Ciuca, A.M., Miclea, M. (2016). PAXonline. Computer mediated psychotherapy for anxiety disorders. EXTENDED ABSTRACT OF THE PHD THESIS.
Attachments [1] 390 0
Results – plain English summary
A growing body of evidence suggests that Internet-based cognitive behavioral treatments (ICBT) are effective to treat anxiety disorders. However, the effect of therapist guidance in ICBT is still under debate and guided ICBT offered in a real-time audio-video communication format has not yet been systematically investigated. This three-arm RCT compared the efficacy of guided with unguided ICBT (12 weeks intervention) and a waitlist (WL). A total of 111 individuals meeting the diagnostic criteria for panic disorder (PD) were randomly assigned to one of three conditions. Primary outcomes were the severity of self-report panic symptoms and diagnostic status. Secondary outcomes were symptoms of depression, functional impairment, catastrophic cognitions, fear of sensations and body vigilance.

Analysis conducted have shown that PAXPD program is efficient in treating panic disorder with comorbidities, and also for secondary outcomes, such as functional impairment and associated depression symptoms, regardless of the delivery modality. Effect sizes are very similar to ones reported in classic CBT therapy (Sanchez-Meca et al., 2010), and even larger than the ones reported in similar previous studies investigating ICBT (Hedman, Ljotsson, Ruck, Bergstrom, Andersson, Kaldo, et al., 2013). The efficacy of PAXPD treatment was also demonstrated for variables accounting for the process of change in cognitive-behavioral therapy: catastrophic cognitions and interpretations, attentional biases and fear towards one’s own physical sensations.

By directly comparing the two groups that received the PAXPD treatment, with and without therapist guidance, our results were similar to the ones reported in other studies (Berger, Caspar, et al., 2011; Berger, Hammerli, Gubser, Andersson, & Caspar, 2011; Botella et al., 2010; Furmark et al., 2009; Olthuis, Watt, Bailey, Hayden, & Stewart, 2015; Titov, Andrews, Choi, Schwencke, & Johnston, 2009). Although at the end of intervention the differences between treatment groups were not statistically significant, the guided treatment proves superiority through larger effect sizes and higher percentage of clinical significance (69% of participants did not fulfill diagnostic criteria for panic disorder). Moreover, the effects of treatment were maintained and even increased after treatment completion. The difference between guided and unguided PAX groups became statistically significant at 6 months follow-up, which again indicates the benefic role of therapeutic assistance in perpetuating and maintaining long term mental health.

There was also a clear superiority of the guided PAXPD treatment in regard to adherence (i.e. number of modules completed and total time spent in the online intervention program) and treatment compliance (frequently of use for the main anxiety reducing techniques). Overall, participants indicated a high level of satisfaction (quality and utility) with the treatment. Comparing the two treatment conditions, we found significant statistical differences in favor of the guided treatment. Of the 66 respondents, 95% (63) said that they would recommend the platform to other people with similar problems and that they would use it again in the future.

This study presents some limitations that should be noted. Firstly, due to financial constraints, the recruitment process had to end before we could reach the target number of participants. This may have reduced the power needed to detect significant differences between the active treatments in our second study objective. Secondly, the dropout rate was rather high, especially at follow-ups and in the unguided group. We tried to counterbalance this loss of data and a possible bias of the results by employing appropriate statistical analyses and chose a conservative approach by treating dropouts as non-responders in the analysis of diagnostic status. Yet, high dropout rates remain one of the major obstacles faced by this type of research.

This is the first study to directly compare a guided and unguided ICBT intervention for panic disorder, in which therapist guidance was delivered via real-time audio-video communication. Both treatments were superior to a waitlist and had similar outcomes at post-treatment. While treatment gains were maintained at follow-ups in both active treatment groups, the guided ICBT intervention became superior on most outcome measures. The study shows that real-time video guidance sessions are beneficial for improving adherence, satisfaction, diagnostic status at post-treatment and long-term outcomes. Future studies should investigate the optimal amount of therapist involvement in real-time video sessions and its use in the personalization of ICBT programs.