Clinical Anxiety Scale for People with Intellectual Disabilities

Abstract

The Clinical Anxiety Scale for People with Intellectual Disabilities (ClASP-ID) is a specialized, informant-rated instrument designed to accurately identify and quantify symptoms of anxiety in individuals with intellectual disabilities (ID), particularly those who also present with Autism Spectrum Disorder. Developed through rigorous research and extensive interviews with both clinicians and parents, ClASP-ID aims to overcome diagnostic challenges, such as the frequent overshadowing of anxiety symptoms by conditions like physical pain or low mood. The scale comprises 33 items and has been empirically validated on a population of parents and caregivers of individuals with ID, confirming its robust psychometric properties and utility in clinical and research settings.

Keywords

Clinical Anxiety Scale for People with Intellectual Disabilities, ClASP-ID, Anxiety, Intellectual Disabilities, Autism Spectrum Disorder, Caregiver Report, Behavioral Assessment, Psychopathology.

Authors

Jessica Eliza Mingins, Joanne Tarver, Effie Pearson, Georgina Edwards, Megan Bird, Hayley Crawford, Chris Oliver, Lauren Shelley, Jane Waite.

Purpose

The primary purpose of the ClASP-ID is to offer a differentiated and specific assessment tool for anxiety in populations characterized by significant cognitive impairment, where self-report measures are often impractical or impossible. By relying on caregiver report, the scale captures externalized behaviors, physiological indicators, and avoidance patterns that are symptomatic of anxiety but may be difficult to interpret in the context of complex needs.

A secondary but critical function of the scale is to assist in differentiating anxiety from other comorbid clinical presentations. The development process specifically sought to include items that distinguish anxiety from indicators of pain or general low energy/withdrawal, thus reducing the risk of diagnostic overshadowing which is common in individuals with profound or severe Intellectual Disabilities.

Construct

The ClASP-ID measures the overarching construct of clinical anxiety as manifested through observable behaviors and reported emotional distress in individuals with intellectual disabilities. The design is based on the premise that anxiety in this population is often expressed somatically or behaviorally, rather than verbally.

The scale is structured around four identified factors, which broadly capture distinct symptom clusters related to anxiety, pain indicators, low energy/withdrawal, and caregiver-reported consolability/coping mechanisms. This multi-dimensional approach ensures a comprehensive profile of the individual’s emotional state and environmental responsiveness.

Validity

The initial development and testing of the ClASP-ID demonstrated strong empirical support for its validity. The scale’s content validity was established through systematic literature review and expert consensus, incorporating input from experienced clinicians and parents who routinely observe these behavioral presentations.

While specific details on concurrent or predictive validity (e.g., correlations with other established measures) are generally provided in the primary publication, the overall assessment of the scale’s psychometric properties confirmed its suitability for clinical use. The clear factor structure further supports the construct validity, indicating that the items effectively measure the intended underlying psychological constructs.

Reliability

The ClASP-ID has been demonstrated to be a reliable measure of anxiety symptoms in its target population. Reliability was assessed during the scale’s development phase, typically involving measures of internal consistency (such as Cronbach’s alpha) across the total scale and its subfactors.

High internal consistency confirms that the 33 items consistently measure the same underlying trait, ensuring that the scale provides stable and reproducible results when used by parents or caregivers reporting on the same individual.

Factor Analysis

The psychometric evaluation of the ClASP-ID, utilizing Factor Analysis, revealed a distinct four-factor structure. These factors represent the specific symptom clusters identified during the scale’s empirical development:

• Anxiety: Core behavioral and emotional signs of fear, worry, agitation, and avoidance.

• Pain: Somatic indicators and protective behaviors that might otherwise be confused with anxiety.

• Low Energy/Withdrawal: Symptoms related to fatigue, lack of interest, and social isolation, which are often comorbid with or mask anxiety/depression.

• Consolability: Items assessing the individual’s ability to be comforted and regulated by caregivers or environmental changes, reflecting coping capacity.

Instrument

Test Type: Questionnaire (Informant/Caregiver Report Scale)

Format: 33 items scored on a 7-point Likert scale.

Language Available: English (Original research publication).

Population Group: Individuals with Intellectual Disabilities (ID), including those with co-occurring Autism Spectrum Disorder.

Age Group: Not explicitly specified, but typically applicable to children, adolescents, and adults whose symptoms are reported by a primary caregiver.

Population Details: Individuals whose cognitive impairments necessitate proxy reporting of psychological and behavioral symptoms.

Test Methodology: Items are rated on a 7-point Likert scale based on the frequency of observed behaviors, ranging from “almost never” to “all the time” or “almost never” to “more than once a day.” Respondents are instructed to report on the frequency of behaviors observed over the last one month.

Keywords

ClASP-ID, Psychometric Properties, Behavior Rating Scale, Diagnostic Overshadowing, Caregiver Burden, Emotional Distress, Intellectual Developmental Disorder.

Authors

Author ORCID Identifier: Not provided in source content.

Affiliation Email addresses: Not provided in source content.

Correspondence Address: Not provided in source content.

Permissions & Fee and Test Year

Permissions for use of the ClASP-ID should be sought from the primary authors or the publishing journal, the Journal of Neurodevelopmental Disorders. The scale was formally developed and published in 2024. Information regarding licensing fees is not contained within the source material. The scale is published in an open-access journal, suggesting that the research paper detailing the scale’s construction is freely available.

Reference’s

Mingins, J. E., Tarver, J., Pearson, E., Edwards, G., Bird, M., Crawford, H., Oliver, C., Shelley, L., & Waite, J. (2024). Development and psychometric properties of the Clinical Anxiety Scale for People with Intellectual Disabilities (ClASP-ID). Journal of Neurodevelopmental Disorders, 16(1). DOI: 10.1186/s11689-024-09554-9.

Items of the Clinical Anxiety Scale for People with Intellectual Disabilities

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

Note. Items are rated on a 7-point Likert scale from “almost never” to “all the time” or “almost never” to “more than once a day.” Respondents are asked to report on the frequency of behaviours over the last one month.