An International Clinical Cross-Sectional Study on Ability and Disability in Autism Spectrum Disorder (ASD) Using the WHO ICF-CY Framework

Background:

The International Classification of Functioning, Disability and Health was developed by the World Health Organization (WHO) to provide a comprehensive and universally accepted framework for describing aspects of health-related functioning. The ICF is based on an integrative bio-psycho-social model of functioning, comprising of 1685 categories related to various components of health, specifically; body functions, body structures, activities (execution of tasks), participation (involvement in life situation) and environmental factors (physical, social and attitudinal environment of people). Although the ICF provides a comprehensive and in-depth description of health-related functioning aspects, using it in clinical practice would be rather impractical, as all categories are not applicable to a certain health condition. To address this issue, the development of ICF Core Sets was initiated; lists of generally agreed-upon ICF categories pertinent to a specific health condition. In this project, Karolinska Institutet Center of Neurodevelopmental Disorders (KIND), in cooperation with the WHO, has initiated the process of developing ICF Core Sets for Autism Spectrum Disorder (ASD). The development process includes four preparatory studies, each aiming to capture specific perspective on functioning and disability in ASD.

Objectives:

This study is the fourth empirical investigation to develop ICF Core Sets for ASD. The objective was to identify common problems in functioning experienced by individuals with ASD in clinical setting as documented by the ICF.

Methods:

An empirical cross-sectional multicenter study was conducted, involving 10 countries from 4 WHO-regions (Eastern Mediterranean, Europe, The Americas and Western Pacific). Experienced clinicians and clinical researchers rated the functioning level of individuals with ASD across the lifespan using an ICF checklist. The checklist consisted of 148 categories, of which 65 were related to activities and participation, 48 to body functions and 35 to environmental factors. The rating of functioning level was based on different information sources, namely medical records, medical history, interviews with participant or caregivers, and clinical observation. Absolute and relative frequency analysis was conducted to identify functioning categories that were considered to be significantly affected by ASD.

Results:

The study yielded in total 122 clinical cases of ASD. To include the most relevant ICF categories pertaining to ASD, only those that were identified to be significantly affected by ASD in at least 10 % of the cases were selected as candidate categories. This left us with 64 activities and participation categories (most identified category; d220 undertaking multiple tasks, n = 106; 87 %), 41 body functions (most identified category; b122 global psychosocial functions, n = 108, 89 %) and 35 environmental factors (most identified category; e310 immediate family, n = 103, 84 %).

Conclusions:

The present study identified broad arrays of functioning aspects and contextual factors to be relevant in ASD, supporting the notion that the impact of ASD extends beyond the core behavioral features of the condition. This study, along with three other preparatory studies, will provide the scientific basis to define ICF Core Sets for ASD, of which assessment or diagnostic tools can be used in multiple settings involving clinical care, education and research.