ZeroPhobia: Self-guided app-based CBT for fear of flying

Our primary research objective is to determine the clinical effects of ZeroPhobia: whether (1) there is a reduction in phobic anxiety symptoms within-participants and between- participants (experimental vs control) post-test and whether (2) effects are sustainable at 3 and 12 month follow-up. Therefore, this primary outcome of anxiety symptoms will be measured using the Flight Anxiety Situations questionnaire (FAS; van Gerwen et al., 1999).

The Flight Anxiety Modality questionnaire (FAM; van Gerwen et al., 1999) will also be used as a secondary measurement of this primary outcome. The FAS focuses on the degree of anxiety evoked by different flight situations, whereas the FAM focuses on the degree of different anxiety symptoms and sensations one could experience during a flight situation (i.e. racing heart rate). General anxiety as measured by the Beck Anxiety Inventory (BAI; Beck et al., 1988) as well as depressive symptoms as measured by the Patient Health Questionnaire (PHQ-9; Kroenke et al., 2007) will be secondary measurements of anxiety and mood changes before and after intervention, which are associated with specific phobia. Questions pertaining to panic disorder, agoraphobia, and OCD from the Web Screening Questionnaire (WSQ; Donker, van Straten, & Cuijpers, 2009) will be assessed as confounding factors.
Our secondary research objectives include determining: (3) the user-friendliness of the intervention, (4) if the usage intensity and/or (5) the feeling of presence influence the primary outcome of ZeroPhobia, (6) if exposure or evaluating thoughts mediate anxiety outcomes, and (7) whether or not ability to fantasize influences the effectiveness of VRET.
User-friendliness will be assessed using the Credibility Expectancy/Satisfaction Questionnaires (CEQ and CSQ; Devilly & Borkovec, 2000). The CEQ is given at pre-test and the CSQ at post-test. The System Usability Scale (SUS; Bangor et al., 2008) will also be given at post-test to understand user-friendliness of the app itself. Usage data will be collected from the app, including when modules are completed and duration spent using ZeroPhobia, to assess whether usage intensity affects primary outcomes.
The IGroup Presence Questionnaire (IPQ; Schubert, Friedmann, and Regenbrecht, 2001) will be used to assess realism and sense of presence in the VR environments. Usage
data on frequency and duration using VRET collected from the app will be used to assess its mediating factors on anxiety outcomes.
The Interpersonal Reactivity Index: Fantasy Sub-scale (IRI; Davis, 1980) will be used to assess participant’s general ability to fantasize and experience absorption/transportation into storylines and artificial situations. This measurement will be further explored in a separate paper.
An assessment of anxiety directly before and after each VR exposure will also be collected for analysis of changes in anxiety. Flight usage will also be assessed (whether or not an individual has flown recently, how long the flight was, etc.) to further assess flight anxiety severity.
Demographic information and whether or not an individual has received other treatment (medication or therapy) during our treatment to remove confounding variables.
A final research objective - to assess whether drop-out is different between guided and un-guided VRET - will be in part assessed using this data; participants of this study will receive unguided VRET, whereas those of our ZeroPhobia: Arachnophobia study will receive guided VRET. Differences in dropout rates will be compared.