The International Classification of Functioning, Disability and Health (ICF) is designed to record and organize a wide range of information about the health of individuals and their health-related states. Over the last few years, the ICF has been developed in a worldwide, comprehensive, consensus process, and it is likely to become the generally accepted framework to describe functioning and health.1
To facilitate a systematic, comprehensive description of functioning and to enable the use of the ICF in clinical practice and research, ICF core sets have been developed. The ICF core sets are generally agreed-upon lists of ICF categories that are relevant for specific diseases or health care contexts, and can be used in clinical studies and health statistics or to guide multidisciplinary assessments.2 The ICF core sets contain as few ICF categories as possible, but as many as necessary, to describe the prototypical spectrum of problems in the functioning and health of patients with a specific condition.3 They can be brief or comprehensive,4 and the World Health Organization encourages the development of core sets for many different clinical situations to examine their impact on population health status and to improve the operational use of the ICF by making it practical and robust in recording information.5 The acceptance and use of the ICF as a framework have been facilitated by the global development and consensus process that has provided growing evidence of its validity.6 It can be used for varied purposes, such as in examining physical health and engagement in special populations.
Benedetti et al7 reported a great difficulty in assessing the behaviors and practices of physical performance due to the lack of standardized instruments with a good level of accuracy for use in population studies and in different social and cultural contexts. Mazo et al8 highlighted the difficulty in obtaining measures of physical health and engagement of older people, especially in studies involving large numbers of participants. Another problem is the lack of instruments that have been properly constructed or adapted for use in this group of people. These and other methodological issues relevant to the assessment of physical activity in older adults were discussed in previous review articles.9,10
Thus, this study seeks to fill these gaps by presenting to the scientific community a useful tool designed specifically for professionals working with older adults to assess their physical health and engagement. In addition, one of the major criticisms of the previously proposed core sets is that these smaller versions of the ICF focus on diseases/disorders, such as low back pain11 or rheumatoid arthritis,12 which are beyond the scope of the initial design of the ICF, namely health. Our understanding is that as an individual has a higher functionality in a characteristic that is classified by the ICF, the person has a greater chance of practicing physical activities, and the opposite is also true. Therefore, the aim of this study was to propose a brief ICF core set to classify the physical health of older adults by Delphi technique.
This research was characterized as a study of accuracy and validity evidence. The research was developed in 2 initial stages: (1) extensive literature review in the main databases about topics related to the project and (2) proposition of a core set.
The third stage of the project is under development, and it involves the application of the proposed core set in an older adult sample to check the results, possibilities, and limitations. This research will be reported in a future publication, which will explain how we classify older adults in terms of their levels of physical activity and correlate this classification with other existing instruments.
The study was approved by the ethics research committee of Onofre Lopes University Hospital by protocol 592/11.
The proposition of the ICF core set was based on the Delphi technique, which was adapted from Jones and Hunter13 and Lemberg et al.14 It aims to gain a consensus from a panel of people with extensive knowledge of the topic being investigated, the so-called “experts.” The strategy includes a series of rounds to both gather and provide information about the participant being examined. The major characteristics of this technique are anonymity, to avoid dominance of single individuals in the group; iteration, which allows panel members to change their opinions in subsequent rounds; and controlled feedback, which shows the distribution of the group's responses, as well as each individual's previous responses.
For the content analysis of the proposed core set, we assembled a panel of experts. Because of the tool's diversity and complexity, the panel included researchers with expertise in ICF and/or physical activity and/or gerontology. Invitations were sent to 20 researchers, who all work at public research and postgraduate institutions of college education in Brazil (since, in Brazil, they have more expertise in the ICF use than clinicians). For several reasons (mainly lack of time), 11 researchers could not participate in the panel, which initially had 9 members. Then, after a researcher requested termination of his participation in the study during its development because of professional commitments, the panel included 8 experts. Jones and Hunter13 have reported that usually 9 to 12 professionals form a group of experts about a given issue.
The 8 professionals were physical therapists, medical doctors, nurses, and physical educators. Geographically, they were distributed in southern and southeastern Brazil, where the foremost national educational institutions are concentrated. The communication was wholly electronic. The worksheets were sent for expert analysis, who could agree to a proposed item, request that an item should be removed, or even suggest new categories. From the received responses, the study coordinator tabulated the data, which were again sent to the experts to obtain further replies. Each round lasted 30 to 40 days. In total, there were 5 rounds of interactivity between the participants until arriving at the final version of the construct.
The analysis was performed using Cronbach α, which is an indicator of the reliability of a questionnaire.15 Terwee et al16 and Barten et al17 reported that Cronbach α is an adequate measure of internal consistency, which gauges the extent to which items in an instrument (sub)scale are correlated, thus measuring the same construct. A low Cronbach α indicates a lack of correlation between the items in a scale, and a very high Cronbach α indicates high correlations among the items in the scale. An α value of 0.70 or more is considered acceptable.
IBM SPSS version 17.0 software (Statistical Package for Social Sciences, Chicago, Illinois) was used, according to the methodological steps proposed by Rosales.18
The initial version of the core set that was forwarded to the experts' panel was built in the first stage of the project (literature review about ICF, ICF core sets propositions, and assessment tools of physical health for older adults). The authors of the study, linked to a research group, proposed an initial version of the core set, consisting of 33 categories (17 categories on body functions, 4 on body structures, 9 on activities or participation, and 3 on environmental factors). Thereafter, subsequent rounds of experts' analysis were necessary to obtain consensus regarding the categories included in the final version of the core set (see Table 1).
The initial version of the core set was analyzed in round 1 and the panel members suggested the inclusion of 14 new categories (4 categories on body functions, 1 on body structures, 8 on activities or participation, and 1 on environmental factors) and the exclusion of 1 category (on body functions). Thus, a second version for round 2 featured 46 categories (20 categories on body functions, 5 on body structures, 17 on activities or participation, and 4 on environmental factors).
The analysis of the second round did not show consensus for several categories (14 to be exact), which were removed, thus resulting in a third version of the construct, with 32 categories (15 categories on body functions, 4 on body structures, 10 on activities or participation, and 3 on environmental factors). This version was again submitted for evaluation by the experts, who expressed their opinions.
In the fourth round, there were few changes in the core set, only 3 categories were removed (2 on body functions and 1 on activities or participation) and 1 was added (body functions). Thus, the instrument now had 14 categories on body functions, 4 on body structures, 9 on activities or participation, and 3 on environmental factors, which totaled to 30 categories.
In the fifth and final round, there was consensus (100% agreement among experts) of version 4 of the instrument. There were no proposed changes. Therefore, the final version with 30 categories (46.7% body functions, 13.3% body structures, 30% activities or participation, and 10% environmental factors) is described in Table 2.
This last version has a Cronbach α of 0.964, and a Cronbach α based on standardized items of 0.966. This value is considered extremely high and indicates the high internal consistency of the instrument.17
Basically, specific instruments to measure the physical health and engagement of older adults are not available. This study seeks to fill these gaps by presenting a useful tool designed specifically for professionals who are working in this field, respecting the philosophy of ICF. The presented core set defines points related to functioning and health that are relevant when evaluating this population, as well as when reevaluating it and monitoring changes.
Several ways are there to propose an ICF core set. For example, Cieza et al19 proposed using regression modeling to identify candidate ICF categories for a generic ICF core set by examining their explanatory power in relation to item 1 of The Medical Outcomes Study Short Form 36. Other researchers proposed the use of a consensus process to integrate evidence gathered from preliminary studies and expert opinions,20–22 as is the case in this research. Versions that take into account the perspectives of patients also exist.23,24
In comparing the proposed ICF core set with those put forth in different countries, Chang et al,25 who conducted a study in Taiwan, proposed a core set for poststroke disability assessment and verification of biopsychosocial problems by using the Delphi method. They selected 51 ICF categories, compared with the 30 categories in the present study. Also, the research of Abdullah et al26 in Malaysia aimed to validate the ICF core set for diabetes mellitus (99 categories). The validation was performed from the patients' perspectives. The results showed that physical and mental functioning were impaired in contrast to what the respondents perceived as leading healthy lifestyles.
Two studies24,27 applied a similar approach to this research; both are core set propositions that were made in Brazil, a country with growing interest in ICF.28 Buchalla and Cavalheiro24 developed a core set for patients with AIDS following high-impact therapy. This work, which took into account the perspectives of patients, resulted in a construct with 40 categories, a result that is similar to the version presented here, despite the difference in focus. Lima et al27 built a core set for evaluating workers with repetitive stress injuries and work-related musculoskeletal disorders. As in the present study, the core set was established using expert consensus. The final consensus was reached after 2 years of work, and the instrument included 104 categories (distributed as follows: 32 categories on body functions, 9 on body structures, 30 on activities or participation, and 33 on environmental factors).
This article presents a core set that is mostly (80%) formed by third-level ICF categories (ie, they have 4 digits), which makes its application more specific by evaluating categories that are not very generic. Furthermore, of the so-called second-level categories, 2 have no third level of specificity (b260 and d160). Take, for example, the evaluation of the energy level category (b1300) rather than the top level energy and drive functions (b130): this assessment would require a much more widespread evaluation. This fact provides a more secure, fast, and accurate instrument. The research of Chang et al25 presents only second-level categories, which generalizes the evaluation.
Riberto4 reported that while comprehensive core sets have 55 to 130 categories, this number varies from 9 to 39 for brief core sets. This study can be classified in the brief core set category, since it presents 30 categories. He also explained that a brief ICF core set for a specific condition should include the minimum number of categories to be practical, but as many as are required to describe the functionality problems as fully as possible. These factors were taken into account when drafting the present core set.
Considering functionality, we can imagine that all of the proposed core set categories will evaluate fields directly related to function. However, this study agrees with the report by Cieza et al,29 who said that a number of factors are relevant indicators of health; therefore, they should be taken into account when creating a categorical profile, even though they will not be considered in scoring the level of functioning. Examples of these categories are d7504 (informal relationships with peers) and e1400 (general products and technology for culture, recreation, and sport). This example reinforces the fact that the creation of the core set took into consideration that health is a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.
When discussing ICF core sets in the evaluation of the older adults, Grill et al30 selected 38 categories to identify the most relevant issues for clinical assessment and monitoring of functioning in older patients undergoing early postacute rehabilitation. Moreover, Grill et al31 aimed to identify the impairments and limitations that indicate loss of independence in older patients after discharge from postacute rehabilitation, which can serve as the minimal standard for the assessment of functioning and health.
To date, there are no data in the literature about core sets for physical activity assessment, which prevent us from making comparisons, but with this proposed core set, these comparisons can be made in future studies.
One of the main problems encountered in this study was the difficulty in forming the experts' panel. Since the experts are extremely competent people, they are also very busy. The panel initially invited 20 researchers, but in the end the panel included 8 experts.
Finally, the goal of this work was to encourage new propositions of ICF core sets to improve the use of this important international classification.
The presented core set is a new tool for assessing the physical health and engagement of older adults. It defines points related to functioning and health that are relevant when evaluating this population, as well as when reevaluating it and monitoring changes. The final version of the instrument is easily administered. Although new research is already being conducted to apply the instrument, additional studies carried out by different professionals will provide support and improve this instrument's validity for clinical practice and research.
The authors thank the experts who kindly provided their valuable contributions and conceded their time to this study. Because of their participation, these experts made the study possible: Cassia Maria Buchalla, Rosângela Corrêa Dias, Célia Pereira Caldas, Tânia Rosane Bertoldo Benedetti, Giovana Zarpellon Mazo, João Marcos Domingues Dias, Eduardo Santana de Araujo, and Felipe Fossati Reichert.
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