Linking the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test (PEDI-CAT) to the International Classification of Function :

Outcome research seeks to understand the end results of health services. Researchers use a wide variety of outcome measures including technical, clinical and patient-oriented measures. The International Classification of Functioning, Disability and Health (ICF) as a common reference framework for functioning may contribute to improved outcome research. The objective of this paper is to provide an updated version of the linking rules published in 2002 and illustrate how these rules are applied to link technical and clinical measures, health-status measures and interventions to the ICF. Three specific linking rules have been established to link health-status measures to the ICF and one specific linking rule has been created to link technical and clinical measures and interventions. A total of 8 linking rules have been established for use with all different outcome measures and with interventions. The newly updated linking rules will allow researchers systematically to link and compare meaningful concepts contained in them. This should prove extremely useful in selecting the most appropriate outcome measures among a number of candidate measures for the applied interventions. Further possible applications are the operationalization of concrete ICF categories using specific measures or the creation of ICF category-based item bankings.

With the approval of the International Classification of Functioning, Disability and Health by the World Health Assembly in May 2001, the concurrent use of both health-status measures and the International Classification of Functioning, Disability and Health is expected. It is therefore important to understand the relationship between these two concepts. The objective of this paper is to provide a systematic and standardized approach when linking health-status measures to the International Classification of Functioning, Disability and Health. The specific aims are to develop rules, to test their reliability and to illustrate these rules with examples. Ten linking rules and an example of their use are presented in this paper. The percentage agreement between two health professionals for 8 health-status instruments tested is also presented. A high level of agreement between the health professionals reflects that the linking rules established in this study allow the sound linking of items from health-status measures to the International Classification of Functioning, Disability and Health.

In 1976, the World Health Organization (WHO) estimated worldwide disability prevalence at 10%; recent evidence suggests the prevalence is even higher. Given the extent of disability around the world, it is essential for researchers and policy makers to have a uniform language for describing and discussing disability. The International Classification of Functioning, Disability and Health (ICF) is WHO's attempt to provide that standard language. Linking rules were published in 2002 and 2005 suggesting a method for standardising the process of connecting outcome measures to the ICF classification. The objective of this study is to study the extent to which the linking rules have been used by researchers to link health and health-related information to the ICF and collect the feedback about the current practices, applications and areas to improve the linking method. Using a systematic review of health-based literature between 2001 and February 2008, we (1) determined research areas where the linking method is applied, (2) examined the characteristics of studies that linked information to the ICF and (3) described current practices and issues related to the process of linking health and health-related information to the ICF both quantitatively and qualitatively. The systematic review yielded 109 articles from 58 journals that linked health information to the ICF and 58 of the articles employed published linking rules. The majority of articles were descriptive in nature, used linking for connecting content of health instruments to the ICF and linked English health content. Quality controls such as reliability checks, multiple raters and iterative linking processes were found frequently among users of the linking rules. Qualitative analysis created themes about: preparing units of information, who links to the ICF, reliability, matching or translating concepts from text to ICF categories, information unable or difficult to capture, quantitative reporting standards and overall linking process. This review also shows that the linking process is a useful way to apply the ICF classification in research. With over 100 articles published in 58 peer-reviewed journals across 50 focus areas, linking health and health-related information to the ICF has been shown to be a useful tool for describing, comparing and contrasting information from outcome measures used to collect quantitative data, qualitative research results and clinical patient reports across diagnoses, settings, languages and countries.