Measurement invariance (MI) is a psychometric property of an instrument indicating the degree to which scores from an instrument are comparable across groups. In recent years, there has been a marked uptick in publications using MI in intellectual and developmental disability (IDD) samples. Our goal here is to provide an overview of why MI is…

Background: Behavioural problems in individuals with intellectual disabilities have a negative impact on them. Limited assessment measures exist in Spain. This study aimed to validate the Behavior Problems Inventory--Short Form (BPI-S) in the Spanish population by examining its psychometric properties and factorial structures. Method: This study…

Background: Studies that have systematically reviewed the psychometric properties of health-related quality of life (HRQoL) and subjective wellbeing instruments for adolescents with intellectual disabilities narrowly focus on disease or health-specific conditions. This review aimed to critically appraise the psychometric properties of self-report…

Background: The Personal Outcomes Scale (POS) is a scale developed to measure quality of life of adults (18+) with intellectual disability. Previous studies have reported good fit for Spanish and Portuguese language versions of POS. Aims: This study aimed to evaluate the factor structure of the English language version of POS when used to measure…

Background: Valid and reliable instruments for measuring emotional development are critical for a proper diagnostic assignment in individuals with intellectual disabilities. This exploratory study examined the psychometric properties of the items on the Scale of Emotional Development--Short (SED-S). Method: The sample included 612 adults with…

Background: The dynamic nature of intellectual disability necessitates repeated screening. Method: The functional screening tool (FST-ID) for individuals with intellectual disabilities was carefully constructed. Results: The FST-ID General Adaptive Composite score (GAC) runs between 0 and 68 points. Criterion validity--high-positive correlations…

Purpose: Wellbeing refers to a person's overall happiness and satisfaction with life. Wellbeing for people with Intellectual and Developmental Disabilities (I/DD) and their families is historically significantly lower compared to the general population. It is important in the context of behavioral health treatment to not only measure the…

There is a need for more knowledge of valid and standardized measures of mental health problems among children and adolescents with intellectual disability (ID). In this study, we systematically reviewed and evaluated the psychometric properties of instruments used to assess general mental health problems in this population. Following PRISMA…

This study describes the adaptation of the autism diagnostic observation schedule (ADOS-2) to assess autism spectrum disorder (ASD) in adults with intellectual disability (ID) and hearing loss who communicate primarily visually. This adapted ADOS-2 was applied to residents of specialized therapeutic living communities (n = 56). The internal…

This study investigated the psychometric properties of the Swanson, Nolan, and Pelham ADHD Rating Scale (SNAP-IV) in a sample of South African children with neurodevelopmental disorders (n = 201), primarily Autism Spectrum Disorder and Intellectual Disability. We conducted a confirmatory factor analysis to inspect the two-factor structure of the…

Background: This paper presents psychometric properties of an instrument for the Assessment of Sexual Behaviour and Knowledge of people with Intellectual Disability (ASBKID), other-reported by professionals who are in daily contact with them. Methods and procedures: Assessments of 236 individuals with intellectual disability were obtained from 100…

The objective of the study was to validate adapted versions of the Glasgow Anxiety Scale for people with Intellectual Disabilities (GAS-ID) simultaneously developed in English and French. A sample of 361 youth with mild to moderate intellectual disability (ID) (M = 15.78 years) from Australia (English-speaking) and Canada (French-speaking)…

CDKL5 deficiency disorder (CDD) results in early-onset epilepsy and lifelong cognitive and motor impairments. With no validated measure for communication in CDD, this study evaluated the psychometric properties of the Communication and Symbolic Behavior Scales-Developmental Profile Infant Toddler Checklist (CSBS-DP ITC). Caregivers (n = 150;…

There are many well-developed screening tools for both intellectual disabilities and autism, but they may not be culturally appropriate for use within Africa. Our specific aims were to complete a systematic review to (1) describe and critically appraise short screening tools for the detection of intellectual disabilities and autism for older…

Introduction: Adults with intellectual disabilities (ID) face a high risk of developing psychiatric disorders, yet there is a lack of valid instruments measuring psychopathology in this population. Two existing instruments are the PAS-ADD Checklist questionnaire and the Mini PAS-ADD interview, two third-party assessments that can be used for the…