Tailoring and standardizing the assessment of ability and disability in ADHD and autism : the development of WHO ICF core sets

Abstract

The concept of health has evolved over time and is today considered a multidimensional construct that involves not only absence of impairments or pathologies, but also quality of life and individual functioning. This conceptualization is especially important to individuals with neurodevelopmental disorders (NDD), as these are characterized by early-onset symptoms that tend to persist into adulthood, interfering with individual well-being, daily life activities and engagement in society. The lack of well-established tools for functioning assessment in NDD marks a significant gap, as there is a substantial interindividual variation in severity of functioning and profile of individual limitations and resources. Hence, diagnosis alone is not sufficient enough to understand individual health outcome in NDD. In 2001, the World Health Organization (WHO) launched the International Classification of Functioning, Disability and Health (ICF), a classification system based on a biopsychosocial framework which seeks to describe and understand health-related functioning, allowing all aspects of an individual’s life to be taken into account. However, the ICF in its current form comprises over 1600 categories of health-related functioning aspects, which makes the implementation of the nomenclature rather infeasible and undesirable in clinical and daily practice. To facilitate the implementation, shorter versions of ICF (i.e. Core Sets) have been developed to describe specific condition or condition groups. This thesis is part of the overarching aim to develop ICF Core Sets (ICF-CS) for two common NDD, i.e. Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD), to standardize individual assessment of functioning and disability in ADHD and ASD.

The development of ICF-CS followed a rigorous and scientific procedure, as established by the World Health Organization (WHO) and the ICF Research Branch, which comprised a series of preparatory studies aiming to investigate relevant aspects of functioning and disability in ADHD and ASD using multiple stakeholder perspective and cross-cultural data sample. In this thesis, two of four preparatory studies are included, of which one explored the client and social environment perspective, whereas the other examined the clinical perspective on functional health in ADHD and ASD. Since the preparatory studies were conducted separately for ADHD and ASD, these resulted in four scientific papers which are included in the thesis.

Study I-II consisted of a mixed qualitative-quantitative study design, involving clients with ADHD/ASD (children, adolescents, adults), caregivers and professionals participating in focus group discussions or individual interviews across five countries and WHO-regions (i.e. Africa, Eastern Mediterranean, Europe, South East Asia, The Americas). The participants were divided into different groups based on age group, stakeholder perspective and country. All discussions and interviews were audio-recorded and transcribed verbatim with meaningful concepts extracted from the transcriptions and linked to ICF categories following a meaning condensation procedure. In study III-IV, a cross-sectional study design was employed, with clinical researchers rating the functioning level of individuals with ADHD and ASD using a checklist with ICF categories. Various types of information sources (e.g. interviews with clients/caregivers, clinical observation, test results, rating scales, medical records) were used to complete the rating. Study I (ADHD) included 76 participants, which generated 82 ICF categories (32 activities and participation; 25 environmental factors; 23 body functions; 2 body structures), 243 personal factors (e.g. personality traits, personal attitudes, behavior patterns) and 4 recurring strengths (e.g. creativity, hyper-focus). The categories in the activities and participation component and environmental factors represented all nine (i.e. learning and applying knowledge; general tasks and demands; communication; mobility; self-care; domestic life; interpersonal interactions and relationships; major life areas; community social and civic life) and five chapters (i.e. products and technology; natural environment; support and relationships; attitudes; services, systems and policies), respectively. Body functions comprised mainly of mental functions, but other areas of the body were also identified, including cardiovascular, sensory, digestive and motor functions. Study II (ASD) included 90 participants, which resulted in 110 ICF categories (45 activities and participation; 33 body functions; 29 environmental factors; 3 body structures), 492 personal factors (e.g. life-habits, personal attitudes, behavior patterns) and 6 recurring strengths (e.g. memory, attention, temperament and personality). The activities and participation component and environmental factors included categories from all nine and five chapters, respectively. Body functions consisted mostly of mental and sensory functions, even though other areas of the body also had some coverage (e.g. digestion, exercise tolerance, motor functions).

In study III (ADHD), 112 clinical cases were contributed from eight countries and four WHO-regions (i.e. Eastern Mediterranean Europe, South East Asia, Western Pacific). In total, 113 ICF categories (50 activities and participation; 33 environmental factors; 30 body functions), 212 personal factors (e.g. life situation/sociocultural factors, personal attitudes, personality traits) and 22 ADHD-related strengths (e.g. social skills, attention, memory) were identified. Similar to study I, all nine and five chapters were covered in the activities and participation component and environmental factors, respectively. Body functions consisted mainly of mental functions, albeit other areas of body functions were identified in this study which were not covered in study I, such as reproductive and speech functions. No body structures were represented in this study, contrary to study I, which covered 2 body structures. Study IV (ASD) comprised 122 cases from ten countries and four WHO-regions (i.e. Eastern Mediterranean, Europe, The Americas, Western Pacific), generating 139 ICF categories (64 activities and participation; 40 body functions; 35 environmental factors), 148 personal factors (e.g. personal attitudes, personality traits, mental factors) and 3 ASD-related strengths (e.g. memory, attention). Categories were from all chapters in the activities and participation and environmental factors component. Most body functions were mental functions, but still this study identified broader aspects of body functions compared to study II, including reproductive and voice and speech functions. This study did not cover any body structures, unlike study II, which included 3 body structures. The large variety of activities and participation categories identified in the different preparatory studies attest to the complexity of ADHD and ASD and the necessity of having a functioning-oriented perspective on well-being and health. Interestingly, certain areas of activities and participation, which are not extensively covered in research or clinical practice, were highlighted as important areas to explore, such as participation in community and civic life, domestic life, self-care and mobility (i.e. using transportation). The chapter coverage of environmental factors was similar to activities and participation, regardless of study and diagnosis, which shows that factors in the environment are vital to assess in order to understand and optimize individual functioning in daily practice. Given that ADHD and ASD are complex diagnoses with heterogeneous impact on well-being and functioning, it is not surprising that different aspects of the environment are highlighted as important determinants of individual health. Body functions comprised mainly of mental functions, but findings suggest other areas of the body to be affected in ADHD and ASD, hence emphasizing an interdisciplinary service and assessment approach. Although not coded in the ICF, the preparatory studies showed that personal factors could add additional information on functioning which may be essential to intervention planning or goal-setting.

In the future, tools will be derived from the ICF-CS for ADHD and ASD and implemented in different settings (e.g. clinics, schools, social services) that play major part in the lives of individuals with ADHD and ASD. The categories in the ICF-CS need to be operationalized into useful items which users (e.g. clinicians, clients, caregivers) can rate with ease and clarity. Users should also be free to add missing ICF categories or add information on strengths, personal factors or other contextual factors which may be pivotal to their everyday life functioning. Qualitative and quantitative outcome measures need to be used to evaluate usefulness of the items as well as administration. Future studies should investigate psychometric properties of ICF-CS based assessment tools and explore how the different ICF components and categories may relate to each other.