A landmark convention by the United Nations (UN) that is likely to have the most impact on persons with disability in recent history is the United Nations Convention on the Rights of Persons with Disabilities (UNCRPD) [1]. The UN adopted the UNCRPD in 2006 with the intent to change the attitudes and approaches to persons with disability, including children. The convention is premised on providing the foundation of human rights for all persons with disability regardless of their disability; it puts persons with disability in equal position to those persons without disability in terms of their rights of access to services and opportunities. This is a critical piece to current efforts by the community advocating for persons with disability whether in the realm of vocational rehabilitation or return-to-work and social security and disability evaluation. The guiding principles of the UNCRPD emphasize the rights of persons with disability with regard to nondiscrimination, full and effective participation and inclusion in society, acceptance of persons with disability as part of humanity, and having equal opportunity, and accessibility [1]. These are essential principles when assessing persons with disability and will need to be integrated in health and health-related policy by the government and organizations that provide services and care for persons with disability so as to optimize their functioning and mitigate their disability. As a major life area of participation for most individuals, work is an integral part of life and everyday living and can seriously be impacted with the presence of a health condition. Hence, our ability to capture disability and work disability in particular is critical.

Published in 2011, the World Report on Disability’s [2] definition of “disability” is mainly predicated on the World Health Organization’s International Classification of Functioning, Disability and Health (ICF) [3] where disability is defined as an umbrella term for impairment of bodily structures and bodily functions, activity limitations, and participation restrictions. Furthermore, disability occurs when there is negative interaction between the health condition and contextual factors such as environmental factors and personal factors that may impact the body and the societal role of a person [3]. The adoption of this broad definition of disability is the first step towards a common understanding of disability and coordinating efforts so as to mitigate disability at the level of the individual while also taking into account the public health perspective.

The ICF provides a comprehensive framework, a consistent classification, and relevant ICF Core Sets for disability evaluation and vocational rehabilitation. The relational concepts of illness and functioning and the emphasis on personal and environmental factors are in concordance with recent advances in social security. An integrative biopsychosocial model is increasingly being considered and used in social security institutions in many countries in the world. The ICF also provides an understanding of the multifocal aspects of functioning that could be used easily in vocational rehabilitation settings and social security systems.

Helping individuals find jobs that are aligned with their interests and abilities is a key task of job development, and vocational assessment should help individuals select suitable occupational goals and services needed to promote their success. Thus, vocational rehabilitation professionals need to assess the correspondence or “fit” between the individual’s interests and abilities and the needs and requirements of the individual’s current or prospective work environment. Where the “fit” is less than optimal, they may determine how to improve it through various types of interventions, such as job accommodations, skills training, and counseling. The ICF framework is ideally suited in providing a holistic approach to vocational rehabilitation that is sufficiently comprehensive for purposes of vocational rehabilitation planning and service provision. Ultimate employment success often depends on the result of variables interacting at both micro (individual) and macro (societal) levels; the ICF can help vocational rehabilitation professionals identify the multiple factors at these levels that have an impact on employment. Identification of these factors can then provide the basis of vocational rehabilitation strategies that are more precisely calibrated to address problems and improve the likelihood of success. A particularly important advantage of the ICF framework is that it helps vocational rehabilitation professionals be more aware of the environmental factors that have an impact on individuals’ ability to perform successfully at school and/or work, as research suggests that environmental variables are likely to be overlooked, while personal characteristics are given more attention.

The full integration of the ICF in social security will take some time. While the framework and to some extent the classification have been adopted in many social security organizations to support and clarify the assessment of the individual’s functional ability and disability, the classification is not widely used. The uptake and progress in implementation might be slow, since social security organizations by tradition act slowly. Changes in policy and working methods have to be channeled through political procedures and could take a long time to prepare, discuss, and decide. An overall general challenge is to make this process as quick and efficient as possible.

Social security organizations need to change their approach to disability evaluation. Many have retained a disease-oriented approach, and there is a need to change to a strong focus on functioning. This indeed requires a paradigm shift and progressive approach in social security. Many countries have started this process. There is a need for functioning assessment and evaluation of work ability in two settings that can be seen in a continuum. One setting is vocational rehabilitation where we need assessments to guide the return-to-work processes; another is the need for assessments to determine the right to benefits. We need to develop ICF-based instruments for these two settings.

It is also a challenge to clarify, define, and describe the link between functioning (as represented by ICF) and disease (as represented by International Classification of Diseases [4]) in the evaluation of rights to disability benefits. One way to address this challenge is by using disease-specific ICF Core Sets. That, however, would add another layer of complexity given the frequent comorbidities that we see in disability evaluations. With the upcoming 11th revision of the ICD, we will see a more integrated biomedical and biopsychosocial approach [5].

The ICF framework is well suited for describing and assessing the individual’s functional capacity and has gained increasing acceptance. However, disability evaluations in social security have to take into consideration several more elements than functional ability, e.g., sociomedical history, prognosis, and causal links. A single classification cannot capture all of these, and the ICF cannot provide a framework for all the questions that need an answer, nor was it ever intended to be a one-size-fit all approach. Rather, the strength of the ICF lies in its inherent role in lending an integrative approach to understanding and measuring functioning and disability alongside other health-related approaches and models.

The perspective of dynamics, i.e., the development of disability in an individual, is not included in the ICF. This dynamic element differs from the elements mentioned above, sinceIt could be said that a classification of functioning also should be able to describe changes in functioning given the proper measurement. Change in functioning is an essential part of disability evaluation in social security. This book pointed out that one way to meet this challenge is to do consecutive measurements and assessments on the individual; an approach that is standardized, robust, and reliable. This would then give an assessor a series of snapshots to estimate as accurately as possible the changes in a person’s functioning.

The vocabulary and definitions of terms provided by the ICF have been assimilated into social security organizations in Europe to some extent. The classification is also receiving more acceptance as a language independent of professions. From the view of social security, there remain challenges related to environmental and personal factors. The environmental factors are at the moment not precise enough for use in social security and would need further development and “granularization” so those factors can be operationalized in a sensible and practical manner. The evaluation of work ability usually requires a more precise description of work demands, work situations, and work environment than the ICF can currently provide. There is a strong need to expand the ICF classification in this dimension in the coming years. Anner et al. [6] have also suggested further development of the environmental factors in order for us to better capture disability and identify the environmental influencers [6]. In the ICF, there is no obvious place to classify vocational rehabilitation interventions of various types. One way of doing this could be to classify them as environmental factors. That would, however, require that a new type of qualifier – interventions – be introduced into the classification, with the possibility to qualify both for positive and negative effects.

The lack of classification of personal factors is one limitation in using the ICF. Other inventories or instruments are necessary if one wants to describe personal factors, like motivation or sense of coherence, in a standardized way in disability evaluations in social security. At present, this standardization is carried out depending on the country, setting, or national policy.

Nevertheless, by taking into account factors of the individual and the environment, the ICF even in its current form brings about a comprehensive overview of the different factors that may impact disability. Without these contextual factors such as social support and type of health services or peer support and access for work productivity, it will be quite difficult to put disability into context as some of those factors can minimize, strengthen, or neutralize the effects of rehabilitative intervention [7, 8]. There are instances when personal factors such as age together with the mental health status may be significantly associated, and which may in turn affect the level of disability at work [9].

The complexity and length of the ICF has hindered its acceptance in some vocational rehabilitation settings. The ICF Core Set for Vocational Rehabilitation [10] should help expedite its use in clinical settings. However, the ICF Core Set for vocational rehabilitation needs further research to assess its further validity and utility in real-life settings. This research could also help identify the areas that are not yet specifically coded in the ICF, particularly for relevant and work-specific environmental factors and categories of activities/participation. Currently, the ICF does include codes for many variables that are known to have an impact on employment outcomes, such as various forms of social support and assistive technology. However, there appears to be a need for additional categories that identify items of importance during the vocational rehabilitation process, including specific items relevant to the job placement process, such as job-seeking skills training, on-the-job support, and job coaching. More precise codes and definitions are also needed in the area of work and employment (Activities and Participation) which can be potentially be mapped to existing job classification systems like the International Standard Classification of Occupations by the International Labour Organization (http://​www.​ilo.​org/​public/​english/​bureau/​stat/​isco/​), or O*NET (http://​www.​onetonline.​org). In addition, there is a need for more clear-cut strategies for identifying vocational rehabilitation interventions when using the ICF. A current problem in job placement research is the lack of consistency in research methodology. The ICF has the potential to address this problem, but without sufficient and precise inclusion of vocational rehabilitation interventions, its potential may be reduced.

Several authors have pointed out that the ICF is too comprehensive to be used in toto. The use of short list – ICF Core Sets – is one way to develop the use of the ICF further. ICF Core Sets for specific diseases were the first to be created according to a defined methodology, and they have been followed by Core Sets for specific settings. The EUMASS Core Set for disability assessment in social security is one example [11], and the development of the ICF Core Set for vocational rehabilitation is another [10]. In social security, the use of disease-specific or setting specific- Core Sets should be discussed and tested. Some European countries have a strong medical influence on the decision process in social security, with a corresponding emphasis on diagnosis. In these countries, modified disease-specific ICF Core Sets might be useful. There are shortcomings with disease-specific ICF Core Sets, and perhaps the most important in social security is the high prevalence of comorbidity in benefit claimants. In many cases there is a combination of somatic and mental conditions that together could limit activity. In such cases, there would be a need for several ICF Core Sets, and that is undoubtedly a complex and cumbersome task to do. Hence, using setting-specific Core Sets would be more cost-effective when several comorbidities exist.