Development of simple, intuitive descriptions
The consensus conference was held in November 2016 in Nagoya, Japan. A total of 21 experts from all regions of Japan and different clinical areas of expertise were assembled to participate in a consensus conference. This group included physiatrists; physical, occupational, and speech therapists; and nurses. Two officers from the Ministry of Health, Labour and Welfare participated as observers. As a result of the predefined process, three initial proposals were accepted in the first step, and 20 proposals were accepted in the second step. The remaining seven ICF categories were decided in the final vote. All participants consented to the final, simple, intuitive descriptions. The English translations of the final versions are shown in Table 1.
Four key topics emerged from a qualitative analysis of the discussion notes: [1] reconciling common clinical terms with the often detailed definitions of the original descriptions of ICF categories; [2] specifying the assumed level of functioning; [3] resolving several different aspects in a given category; and [4] handling the wording of the original definitions of ICF categories which are unfamiliar to Japanese clinicians.
1) Reconciling common clinical terms with the often detailed definitions of the original descriptions of ICF categories
Several participants indicated that numerous ICF definitions are excessively detailed for clinicians. For instance, the ICF category d450 Walking is described as ‘Moving along a surface on foot step by step so that one foot is always on the ground, such as when strolling, sauntering, walking forwards, walking backward or walking sideways’. However, from a clinical perspective, several raters in our study noted that this description is detailed but the usefulness of the description in clinical practice is constrained. For example, d450 has two subcategories, namely, d4502 Walking on different surfaces and d4503 Walking around obstacles, which refers to the walking outdoors or rough road. The description of these categories, however, are not reflected in the definition of d450. Walking on a flat floor indoors compared with the walking on a rough road outside might involve substantially different levels of difficulty, and any relevant rating for these activities should reflect the realities that clinicians deal with on a daily basis. As a result, the simple, intuitive description of d450 was agreed upon to be walking on level ground (including walking outdoors and walking on a rough road). This case also illustrates how examples were used in numerous descriptions to clarify their meanings and to define the scope of scoring in the corresponding categories.
2) Specifying the assumed level of functioning
Individuals can perform physical activities at a very wide array of levels. For example, for elite athletes, a slight decrease in muscle strength would be a critical problem. By contrast, such levels of difference might be almost irrelevant for patients after hip surgery. In light of this reality, our participants suggested that our new descriptions should leverage the common understanding of clinicians and facilitate the use of the ICF by including target levels of performance. For example, the simple, intuitive description of b730 Muscle power functions was refined to ‘Muscle strength that is required for daily living’. In this case, there was a discussion on whether the words ‘required for daily living’ should be included because this phrase is not included in the original definition of b730 Muscle power functions. However, considering that this description aims to help clinicians use the ICF and its rating system in daily clinical settings, this addition was readily justified by the participants.
3) Resolving several different aspects in a given category
Some participants indicated that ICF categories which included multiple elements in their descriptions should also be described in the simple, intuitive descriptions in detail, whereas others argued for keeping the descriptions simple and concise. The participants agreed eventually to include more detail when it was beneficial to enhance the clarity of the description of a given ICF category. For example, the category d410 Changing body positions was explained as ‘Changing body position such as standing up, sitting down, lying down and squatting’ because the scope of evaluation should be shown for clarification in this case.
4) Handling the wording in the original descriptions of ICF categories that is unfamiliar to Japanese clinicians
For many cultural and linguistic reasons, some ICF definitions are unclear to practitioners in Japan. For example, the ICF description of b130 Energy and drive functions is ‘General mental functions of physiological and psychological mechanisms that cause the individual to move towards satisfying specific needs and general goals in a persistent manner’. 2. However, it was agreed that the phrase ‘to move towards satisfying specific needs’ is not intuitive for Japanese clinicians. Thus, in the Japanese version of simple, intuitive descriptions, this phrase was modified to ‘Mental functions that cause self-driven activities in daily life’ even though the phrase ‘self-driven activities in daily life’ is not part of the original ICF. However, it was used here because our participants considered that it nicely summarised subcategories such as b1301 Motivation, b1302 Appetite or b1303 Craving, all of which are more intuitive for Japanese clinicians.
Development of the rating reference guide
In the next step, we developed the rating reference guide for the activity and participation categories in the ICF Generic-30 Set, based on the cognitive interviews with three rehabilitation experts (a physiatrist, a physical therapist and an occupational therapist) who rated nine patients with using simple, intuitive descriptions (Tables 2, 3). Three were acute patients, three subacute patients and three chronic patients. Five patients had a neurological disease, two had orthopaedic diseases and two had respiratory diseases. The cognitive interviews and the subsequent discussion suggested that the reference guide should reflect the different considerations for rating activity-related categories involving the execution of basic everyday tasks which individuals need to do for themselves to live, such as toileting and eating, versus rating participation-related categories involving engaging in activities related to a social context, such as interpersonal interactions and work. Consequently, the ICF categories were divided into two respective groups.
1) Ratings for activity-related ICF categories (Table 2)
For activities such as toileting and eating, agreement was reached easily because links were drawn to existing clinical scales that address similar items, such as the Functional Independence Measure (FIM) 18and the Barthel Index (BI)19. In activity-related ICF categories, the severity rating was largely determined by the requirements for human support, which basically reflects the style of existing clinical scales. However, this was broadened to include the need for many types of assistance devices and to also include the existence of mental barriers. In this section, there was substantial discussion regarding d450 Walking, because the functioning level required for walking indoors and walking outdoors and rough loads can be quite different 20, 21. As a result, d450 Walking was split up into two items: walking indoors and walking outdoors and rough loads.
2) Ratings related to participation-related ICF categories (Table 3)
For the ICF categories referring to the participatory engagement of a person in daily life, it was agreed that a rating based solely on the degree of assistance required would not be appropriate. It is possible that some individuals who have difficulty in executing a task would be able to execute the task with modifications but without needing assistance. For example, a patient with fibromyalgia may be able to work without assistance from others but only with a modified number of hours, i.e. part-time instead of full-time. In this case, if the rating was solely based on the need for assistance and not also on the required modification, the rating reflect better functioning than in reality. Thus, it was agreed that the guide should consider both the restrictions in execution as well as the support required. The description of possible restriction was developed from the results of cognitive interviewing. The support required for the participation-related categories and for the activity-related categories were described similarly.
For d710 Basic interpersonal interactions and d770 Intimate relationships, the rating guide was developed differently. While some patients in some cases need support or have restrictionin in these types of interpersonal relationships, some do not. Thus, the rating guide for these categories were worded more broadly, and focused on the problem in the interaction itself rather than on the support the patient needs. The rating reference guide for d710 referred to “apparent problems in showing respect, warmth and coordinating different opinions”, and for d770 Intimate relationships refers to the problems that “apparently fundamentally affect creating and maintaining intimate relationships” .
Once the draft of the rating reference guide was available, the ICF experts raised further concerns regarding possible inconsistencies among the categories and with the original coding guideline for ICF. For example, there was some inconsistency in the wording within the activity-related categories even though the content was quite similar. Thus, the guide for those categories was modified to be as similar as possible in terms of wording. There were also several cases with the inconsistency with the original coding guideline or the simple, intuitive descriptions. In such cases, the reference guide was modified to avoid any discrepancy with the original ICF and simple, intuitive descriptions.
Interrater reliability
Of the 100 patients recruited 84 were receiving rehabilitation services in the university hospital and 16 were healthy individuals over 65 years old. Sixty-five were males, and 35 were females; 55 patients had neurological diseases, 15 patients had orthopaedic diseases, 10 patients had cardiopulmonary diseases and four patients had various other issues (mostly renal and gastric in nature). The median days after onset was 58 (ranged 1 to 6403). The mean age of our subjects was 66 ± 17 years.
Missing values, including response options ‘not specified’ and ‘not applicable’, of more than 5% were present in 11 of the 21 ICF categories. No missing values were observed in seven categories.
Table 4 shows interrater reliability with percentages for complete agreement and kappa statistics (using linear weights) for individual ICF categories. The mean interrater agreement for the categories was 75.4% (ranging from 49.4% to 88.9%) indicating substantial agreement. Weighted kappa statistics showed a reliability of 0.6 or higher in all categories and 0.8 or higher (substantial agreement) in four of the categories (ranging from 0.61 to 0.85).