Exposure Therapy for Late-life Anxiety

• Anxiety severity will be assessed with the Geriatric Anxiety Inventory (GAI). The GAI is a self-report measure of general anxiety symptoms over the last week. Total scores range from 0-20, with higher scores indicating greater anxiety.
• The second questionnaire used is the EuroQol 5-Dimension 5-Level version (EQ-5D-5L), which is used to measure quality of life. It has five subscales consisting of mobility, self-care, usual activities, pain/discomfort and anxiety/depression. The 3L classification system defines the 243 health states by combining different levels (one from each dimension), ranging from 11111 (full health) to 33333 (worst health). The 5L classification system comprises the same five dimensions as the 3L, but each dimension has two more levels to the existing three levels. Accordingly, the 5L system defines the 3,125 health states ranging from 11111 to 55555.

Both questionnaires will be used during the 12-week treatment period and during the 1-year follow-up.

The aim is to relate the incremental costs of ET compared with UC to the incremental health effects. Both a cost-effectiveness analysis (CEA) and a cost-utility analysis (CUA) will be performed from a societal and healthcare perspective.

• For the cost-effectiveness analysis Quality-Adjusted Life-Years (QUALYs) will be assessed with the EQ-5D-5L.
• Anxiety severity will be assessed with the Geriatric Anxiety Inventory (GAI). Total scores range from 0 to 20, with higher scores indicating greater anxiety.
• To assess societal costs, the TIC-P will be used. This questionnaire is the modified version of the Trimbos and iMTA questionnaire on Costs associated with Psychiatric illness (TiC-P). Cost categories that will be included are: 1) healthcare costs; 2) lost productivity costs; 3) patient costs. Valuation will be done according to Dutch costing guidelines. Higher scores indicate higher societal costs.

• Social Anxiety: Liebowitz Social Anxiety Scale (LSAS), total score ranging 0-144.
• Generalized Anxiety Disorder (GAD): GAD-7 scale, total score ranging 0-21. 3) Panic Disorder: Panic Disorder Severity Scale-Self Report (PDSS-SR), total score ranging 0-28.

For all three questionnaires is a higher score an indication for more severe anxiety.

• Agoraphobia: Mobility Inventory (MI), 27 items rated from 0 (never avoids) to 4 (always avoids). Scores are averaged based on situations experienced alone or accompanied.

Depressive Symptoms: Quick Inventory of Depressive Symptoms (QIDS-SR), total score ranging 0-27. Higher scores indicate greater severity.

General Functioning: 12-item World Health Organization Disability Assessment Schedule (WHODAS 2.0). Average scores 1 (no disability) to 5 (extreme disability).

Medication use: use of benzodiazepines and antidepressants, binary yes/no.

• Ageist biases of participants and mental health nurses will be measured using the 12-item Shortened Expectations Regarding Aging Survey (ERA-12), consisting of 3 subscales and total score ranging 0 to 100.
• Cognitive functioning will be measured with Montréal Cognitive Assessment scale (MoCA) total score ranging 0-30.
• Therapeutic expectations will be measured with Credibility & Expectancy Questionnaire with 6 items. This measure is scored on a Likert scale ranging from 1 to 9 (e.g., 1 means 'not at all', 5 'somewhat', and 9 'very much') or from 0% to 100% (in 10-point increments). Items 4 and 6, coded from 0%-100%, are converted linearly on a Likert scale from 1 to 9.
• Therapeutic alliance will be measured with Working Alliance Inventory (WAI), total score is the average of 12 items, with a maximum score of 5.

• Threat expectancy: As part of the treatment protocol, participants rate: Before exposure: Threat expectancy (0-100%) - likelihood of feared outcome. After exposure: Threat occurrence (0-100%) - extent of feared outcome, and Adjusted threat expectancy (0-100%) - likelihood of outcome if repeated.

• Avoidance will be measured with:

• Brief Experiential Avoidance Questionnaire (BEAQ), 15 items, rated 1-6.
• The Cognitive-Behavioural Avoidance Scale (CBAS), 31 items, rated 1-5, measuring different types of avoidance.
• Safety Behaviours: Safety Behaviour Scale (SBS), 14 items, rated 0-4.
• Self-Efficacy: General Self-Efficacy Scale (GSE), total score 10-40. Higher scores indicate greater self-efficacy.

Metacognitions: Metacognition Questionnaire-30 (MCQ-30), total score 30-120. Higher scores indicate more unhelpful metacognitions.

Worry: Assessed with the Penn State Worry Questionnaire (PSWQ), 16 items, rated 1-5.