Introduction
The Mobility Inventory for Agoraphobia (MIA) is a 27-item self-report questionnaire that measures the severity of agoraphobic avoidance and the frequency of panic attacks. Dianne L. Chambless and colleagues at Temple University Medical School published it in 1985. Uniquely, it rates avoidance both alone and with a trusted companion, and it has received more than 1,130 citations.
The original study appeared in Behaviour Research and Therapy. This guide explains the MIA's situations and scoring, its cut-off scores, its psychometric evidence and how clinicians and researchers use it.
Key Features of the Mobility Inventory for Agoraphobia (MIA)
Purpose and Use
The MIA helps clinicians and researchers evaluate how much a person avoids specific places or situations because of anxiety. Importantly, it does so both when the person is alone and when a trusted companion is present.
Target Population
The MIA is intended for adults aged 18 and older.
Structure
The MIA contains 27 items: 26 situations rated for avoidance, plus one item on panic attack frequency. The situations include:
Theatres, supermarkets, classrooms, department stores, restaurants, museums and auditoriumsElevators, parking garages, high places, enclosed spaces and open spacesRiding in buses, trains, subways, airplanes, boats and carsStanding in lines, crossing bridges, parties and walking on the streetStaying at home alone and being far from homeFactor analysis revealed three components: avoidance of public places, enclosed spaces and open spaces. A final item asks how many panic attacks the person had in the past week.
Scoring Method
Respondents rate each situation twice, once for when they are alone and once for when they are accompanied, on a 5-point scale:
1 = Never avoid2 = Rarely avoid3 = Avoid about half the time4 = Avoid most of the time5 = Always avoidRatings are averaged across situations to produce two scores, each ranging from 1.00 to 5.00:
Avoidance Alone (MI-AAL): the average rating when unaccompanied.Avoidance Accompanied (MI-AAC): the average rating with a trusted companion.Panic frequency: the number of panic attacks in the last 7 days, with no fixed maximum.Higher averages indicate more severe agoraphobic avoidance. Respondents may skip situations irrelevant to their lifestyle; however, the scale is invalid if more than 5 items (about 20%) are skipped.
Cut-off scores: NHS IAPT guidelines use a mean item score above 2.3 on the Alone scale as a sign of clinical concern. Empirical ROC studies support an optimal cut-off of 1.61 on the Alone scale to identify clinical agoraphobia.
Administration Format
The MIA is a self-report questionnaire, so respondents complete it themselves, rating every situation for both conditions.
Applications of the Mobility Inventory for Agoraphobia (MIA)
The MIA is relevant in both clinical and research settings:
Clinical assessment: showing a patient's functional limitations and reliance on companions.Treatment planning: identifying which situations a person avoids alone versus accompanied.Anxiety research: measuring agoraphobic avoidance and panic frequency.Languages and availability
Researchers have adapted the MIA in several languages, including a Polish adaptation and validation. The MIA is publicly available, for example as a PDF.
Reliability and Validity
The MIA has strong psychometric properties across multiple cultural adaptations. Notably, the Alone and Accompanied subscales correlate only moderately, which confirms that they assess distinct aspects of avoidance.
Validation studies:
The Mobility Inventory for Agoraphobia (1985): study linkPsychometric properties of the Mobility Inventory for Agoraphobia (2011): study linkThe Mobility Inventory for Agoraphobia Avoidance Alone Scale: factor structure (2016): study linkPolish adaptation and validation of the Mobility Inventory: study linkLimitations and Considerations
Keep these points in mind:
Skipped items: the scale is invalid if more than 5 items are skipped.Cut-offs differ: the 2.3 (NHS IAPT) and 1.61 (ROC) thresholds come from different sources, so report which one you use.Self-report: scores reflect how respondents describe their own avoidance.Other Versions And Related Questionnaires
These measures are similar or complementary to the MIA:
Agoraphobic Cognitions Questionnaire (ACQ), which measures fear of physical or catastrophic consequencesBody Sensations Questionnaire (BSQ), which assesses fear of physical sensationsFear Questionnaire (FQ) Agoraphobia subscale; see the ResRef FQ guideAnxiety Disorders Interview Schedule (ADIS-IV), a clinician-administered diagnostic toolAdditional Resources
The original article: linkA PDF of the Mobility Inventory from the University of Pennsylvania: linkAn overview on Online CBT Resources: linkFor inquiries, the original contact is Dianne L. Chambless, Department of Psychiatry, Temple University Medical School, Philadelphia, PA 19140, USA (as of 1985).Browse more anxiety questionnaires in the ResRef database.Frequently Asked Questions (FAQ)
What does the Mobility Inventory for Agoraphobia measure?The MIA measures how often a person avoids 26 situations because of anxiety, both alone and with a trusted companion, and records the number of panic attacks in the past week.
How is the MIA scored?Each situation is rated from 1 (never avoid) to 5 (always avoid). Ratings are averaged into Avoidance Alone and Avoidance Accompanied scores, each from 1.00 to 5.00.
What is a clinical cut-off on the MIA?NHS IAPT guidelines use a mean above 2.3 on the Alone scale for clinical concern, while ROC studies support 1.61 on the Alone scale to identify clinical agoraphobia.
Why does the MIA rate avoidance alone and accompanied?Rating both conditions captures reliance on a "safe person", common in agoraphobia. The two subscales correlate only moderately, so they reflect distinct aspects of avoidance.
A Word from ResRef About the Mobility Inventory for Agoraphobia (MIA)
The Mobility Inventory for Agoraphobia is a well-established, evidence-based instrument that remains highly relevant in both clinical and research settings. Its simple yet effective design – rating avoidance in two social conditions – provides clinically actionable insights into a patient's functional limitations and reliance on companions. With excellent psychometric properties, publicly available access, and validation across multiple languages, the MIA represents a benchmark tool for assessing agoraphobic avoidance.
References
Chambless, D. L., Caputo, G. C., Jasin, S. E., Gracely, E. J., & Williams, C. (1985). The Mobility Inventory for Agoraphobia. Behaviour Research and Therapy, 23(1), 35–44. https://doi.org/10.1016/0005-7967(85)90140-8Chambless, D. L., Sharpless, B. A., Rodriguez, D., McCarthy, K. S., Milrod, B. L., Khalsa, S., & Barber, J. P. (2011). Psychometric Properties of the Mobility Inventory for Agoraphobia: Convergent, Discriminant, and Criterion-Related Validity. Behavior Therapy, 42(4), 689–699. https://doi.org/10.1016/j.beth.2011.03.001Hoffart, A., Øktedalen, T., Ulvenes, P., & Johnson, S. U. (2016). The Mobility Inventory for Agoraphobia Avoidance Alone Scale: Factor Structure and Psychometric Properties of Subscales. Assessment, 25(6), 769–776. https://doi.org/10.1177/1073191116659739