Validation of the Comprehensive ICF Core Set for Vocational Rehabilitation From the Perspective of Physical Therapists: International Delphi Survey

Discussion

In an international 3-round email Delphi survey, consensus was reached among physical therapists working in VR concerning the domains on functioning that are relevant when evaluating or treating clients in VR. Consensus was assumed if at least 75% of the participants agreed on a domain. This cutoff was chosen based on previous ICF validation studies.^32,33 The 75% arbitrary cutoff supports core responsibilities of physical therapists in VR, whereas using a lower cutoff of 70%, for example, would have included ICF categories such as b164 (higher cognitive function) (71%) and d240 (handling stress) (73.6%), which may or may not directly relate to entry-level physical therapist practice. These results added knowledge and identified the gap and future opportunities for further examining the role of physical therapists in the field of VR. The existing ICF and the ICF Core Set for VR, which was developed as a multidisciplinary standard to evaluate the whole continuum of VR, were used for reference.

In the Brief ICF Core Set for VR, our survey participants identified only one category, b455 (exercise tolerance function), as relevant when evaluating and treating clients in VR. This finding is consistent with the WCPT description of physical therapy, as exercise tolerance function is the only category in the Brief Core Set that is closely related to movement and functioning compared with the remaining 12 categories, which are related to cognitive or social functioning, employment, and environmental factors.

In the Comprehensive ICF Core Set, the participants identified 15 (17%) of the categories as relevant targets for physical therapists in VR: 6 categories from the component body functions and 9 categories from the component activities and participation. In addition, 9 chapter-level categories (3 body functions, 2 body structures, 3 activities and participation, and 1 environmental factor) and 13 second-level categories not included in the ICF Core Set for VR (3 body functions, 7 body structures, and 3 activities and participation) were identified as relevant for physical therapists in VR (Tab. 2). On the other hand, the current Guide to Physical Therapist Practice (the Guide) defines the role of physical therapists, in part, as: “use[s] tests and measures to make judgment as to whether an individual is prepared to assume or resume work-related roles, including activities of daily living (ADL) and instrumental activities of daily living (IADL), or to assess the need for assistive technology or environmental adaptations.”³⁴ Thereby, the Guide refers to ADL and IADL activities that are only partially included in the ICF Core Set for VR but identified to be relevant in VR to a lesser extent by the study participants.³⁴ For example, although the assessment of assistive technology and environmental adaptations is recommended by the Guide as interventions to be considered in physical therapy treatment in VR and is covered in the ICF Core Set for VR in the chapter “e1: products and technology,” these interventions were not confirmed by the physical therapists in our survey. The physical therapists identified only the environmental factor (eg, “social support at home and work,” “support from family,” “cooperative colleagues,” or “social workers”) covered by the ICF chapter “e3: support and relationship” as relevant for their work. It remains unclear whether, in interdisciplinary teams, these interventions are carried out by other health professionals,³⁵ or if contrary to recommendation (eg, the Guide or the ICF Core Set), assistive technology assessment and environmental adaptations are not considered.

When looking at the level of specificity that was considered as relevant in VR, both the Guide and the ICF Core Set for VR describe the relevant factors in VR from a broader perspective than some of the physical therapists who reported relevant factors on a more specific level (third and fourth levels of the ICF). The broader perspective of the Guide and the Core Set might be needed to integrate the perspective of physical therapists into a comprehensive overall take on VR covered by the multiple disciplines engaged in the field of VR. On the other hand, the physical therapist clinician might need a more detailed view with regard to daily clinical routine with a client.³⁶ For example, in the interdisciplinary setting, addressing pain in a more generic way, as described in the second-level category b280 (pain functions), may be sufficient, whereas a physical therapist will evaluate and document pain problems in a more detailed way (eg, b28013: pain in back). For the same reason, physical therapists might have agreed on the 22 additional aspects of functioning or ICF categories not covered by the present ICF Core Set for VR but considered relevant in day-to-day practice of VR (eg, b710: mobility of joint functions, d920: recreation and leisure). Especially for the category d920 (recreation and leisure), there is increasing evidence that keeping a healthy balance between work and recreation as a basis for sustained work productivity is important.^37,38

Categories defining ADL and IADL were named by participants in the study but were mostly eliminated in further rounds (eg, d510: washing oneself, d540: dressing, d420: transferring oneself). It is an issue as to what extent physical therapists in VR have to examine and treat ADL or IADL or whether these categories belong to a general rehabilitation setting. Interestingly, the results of our study show that physical therapists do not feel the relevance of assessing assistive technology in RTW strategies. On the other hand, when looking at the results, physical therapists in VR considered evaluating and treating categories from the component body structures (ie, naming 13 categories from that component) to be relevant. However, the assessment and treatment of body structures is not recommended in the Guide, nor are body structures included in the ICF Core Set for VR.³⁴ A body structure–focused examination and intervention has been the traditional approach for many decades in medicine, as it brings impairment-related information that might be important in mitigating the consequences of work disability. However, complementing body structure information with a focus on activities and participation and environmental factors can facilitate optimal RTW by considering the broader aspect of the client's functioning.

Even though physical therapy in VR seems to be a specialized field, it stands out that body functions, such as the categories b280 (sensation of pain), b455 (exercise tolerance functions), b730 (muscle power functions), and b740 (muscle endurance functions), address common physical therapy target goals in other settings as well.^34–36 However, the categories b126 (temperament and personality functions) and b130 (energy and drive functions) can generally be considered as essential prerequisites for successful VR outcome. The latter 2 categories emphasize the need for physical therapists in their clinical decision-making process to identify and refer to other disciplines to address those aspects of functioning that do not necessarily fall directly within the scope of physical therapist practice.

When looking at the identified activities and participation categories, it is remarkable that 8 of the 9 categories belonged to “mobility.” These findings are consistent with the definition of general physical therapy core domains, which states, “Physical therapists are health care professionals who help…maintain, restore and improve movement.”³⁵ One category—d825 (vocational training)—represents a major strategy in VR, which is commonly not part of traditional physical therapy treatment and is often addressed separately by vocational rehabilitation counselors and job coaches.

Another 5 categories of the Core Set are covered only by the chapter level: b1 (mental functions), b2 (sensory functions and pain), d5 (self-care), d7 (interpersonal interactions and relationships), and e3 (support and relationships). This finding means that physical therapists acknowledged the importance of these broad domains but may not need the specific information afforded by second-level categories or that more detailed information is implicitly subsumed using the broad domains (at the chapter level). Noteworthy to mention is the difference between experts and novice therapists (≤2 years of experience). The novice therapists named relevant factors to consider in their daily practice in a detailed manner, whereas experts often use only information on a chapter level, implying that experts may not necessarily exclude specific information but use a broad overview of the domain for guidance. On one hand, this possibly raises the issue of the confidence of being able to discern the need for specific information or not depending on the context of the VR situation, which can be influenced by a lengthy experience in clinical practice. On the other hand, recent physical therapy graduates may not yet have sufficient experience to acquire a comprehensive overview of functioning and thus resort to more detailed information.

However, this study also had some limitations. Despite the broad recruitment of experts by contacting the WCPT and the representatives of the national physical therapy associations, via their websites on the Internet and on LinkedIn, the number of physical therapists in VR willing to participate in the survey was limited in comparison with the theoretically large sampling frame of physical therapists available who may be practicing in a VR-like setting. This low participation might have been due to the fact that VR is internationally still seen as a developing practice area of physical therapy, and even though physical therapists may commonly address RTW as a goal with their clients, they might not consider themselves to be experts in the field of VR. The lack of infrastructure and establishment of a VR program in some regions of the world also poses another challenge. Having analyzed the subgroup data by WHO region, it was interesting to see how different regions had answered, and the data showed that the therapists from strongly represented regions with multiple participants (Americas=7, European=26, and South-East Asia=7) had agreed in choosing much more specific categories than therapists from regions with fewer participants. This finding may indicate that these effects are due to differences in professional education and diverse representation of international “standards” concerning VR. Participants from countries with more differentiated answers have facilitated access to VR programs. Moreover, there might be a lack of established infrastructure concerning the delivery of VR in a particular country or region.³⁸

The diverse backgrounds of the experts with respect to experience or expertise in a wide range of health conditions and VR settings, as well as in education and research, and the global distribution of participants from all 6 WHO regions provided heterogeneity of participants, which would probably reflect a realistic global composition of physical therapists practicing in VR. The composition of participants, therefore, supports the first requirement on validity in a Delphi exercise, which is to identify diverse sources of information.³⁹

Nevertheless, the external validity of the results has to be investigated in specific cultural or health care settings. The International Federation of Physical Therapists Working in Occupational Health and Ergonomics Group, formed at WCPT Congress in Vancouver, Canada, in 2007, can further advance and support this development from a global perspective, alongside the support of national physical therapy associations.

To be able to compare the findings of the Delphi survey with the ICF Core Set for VR, all final ICF codes derived from the survey were transformed to the second level. Therefore, more specific information relevant to physical therapists might have been lost in the process. For example, category b1301 (motivation), which was chosen by 92.5% of the respondents, was aggregated for comparison reasons to the second-level category b130 (energy and drive functions). The aspect of motivation might be lost to physical therapists not so familiar with the ICF taxonomy, such that the aspect of “motivation” is subsumed by the concept of “energy and drive.”

To conclude, it can be shown that physical therapists treating clients in VR consider aspects of functioning to be relevant and to belong to the common domains of physical therapist practice. In daily practice, physical therapists are responsible for a specific part of the ICF Core Set for VR that belong to the core competencies of physical therapy, such as d4 (mobility) and b7 (neuromusculoskeletal and movement-related functions). In addition, the results show that physical therapists consider additional aspects of functioning to gain a broader overview of their client's situation in RTW. Further categories as identified in this study may be used by the physical therapists to evaluate and document functioning of their clients in VR. It can be stated that the content validity of the Comprehensive ICF Core Set for VR is insufficient from solely a physical therapist's perspective. However, the Comprehensive ICF Core Set makes sense to clarify competencies and responsibilities of physical therapists in a multidisciplinary setting or when communicating with other professionals and to facilitate an integrative and comprehensive rehabilitation management. Even though, in its entirety, the ICF Core Set for VR is too comprehensive for monodisciplinary use in physical therapist practice, the results of this study could be used to define a physical therapy–specific set of ICF categories to guide clinical physical therapist practice in VR.

With this survey, the core competencies for physical therapists treating clients in VR could be clarified at least from a global perspective. This clarification would allow an allocation of the competencies and responsibilities in an interdisciplinary team in the context of VR, which leads to optimal RTW outcomes.