Items from patient-oriented instruments can be integrated into interval scales to operationalize categories of the International Classification of Functioning, Disability and Health

ICF Research Branch, WHO Collaborating Center for the Family of International Classifications, German Institute of Medical Documentation and Information, IHRS, Ludwig-Maximilian University, Munich, Germany.
Journal of clinical epidemiology (Impact Factor: 5.48). 07/2009; 62(9):912-21, 921.e1-3. DOI: 10.1016/j.jclinepi.2008.04.011
Source: PubMed

ABSTRACT To exemplify the construction of interval scales for specified categories of the International Classification of Functioning, Disability and Health (ICF) by integrating items from a variety of patient-oriented instruments.
Psychometric study using data from a convenience sample of 122 patients with rheumatoid arthritis. Patients completed six different patient-oriented instruments. The contents of the instrument items were linked to the ICF. Rasch analyses for ordered-response options were used to examine whether the instrument items addressing the ICF category b130: Energy and drive functions constitute a psychometrically sound interval scale.
Nineteen items were linked to b130: Energy and drive functions. Sixteen of the 19 items fit the Rasch model according to the chi-square (chi(2)) statistic (chi(2)(df=32)=38.25, P=0.21) and the Z-fit statistic (Z(Mean)=0.451, Z(SD)=1.085 and Z(Mean)=-0.223, Z(SD)=1.132 for items and persons, respectively). The Person Separation Index r(beta) was 0.93.
The ICF category interval scales to operationalize single ICF categories can be constructed. The original format of the items included in the interval scales remains unchanged. This study represents a step forward in the operationalization and future implementation of the ICF.

Download full-text


Available from: Roger Hilfiker, Jul 03, 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The 39-item Parkinson's disease questionnaire (PDQ-39) is the most widely used patient-reported rating scale in Parkinson's disease (PD). However, recent studies have questioned its validity and it is unclear what scores represent. This study explored the possibility of regrouping PDQ-39 items into scales representing the International Classification of Functioning, Disability, and Health (ICF) components of Body Functions and Structures (BF), Activities and Participation (AP), and Environmental (E) factors. An iterative process using Rasch analysis produced five new items sets, two each for the BF and AP components and one representing E. Four of these were found to represent clinically meaningful variables: Emotional Impairment (BF), Gross Motor Disability (AP), Fine Motor Disability (AP), and Socioattitudinal Environment (E) with acceptable reliability (0.73-0.96) and fit to the Rasch model (total item-trait chi-square, 8.28-33.2; P > .05). These new ICF-based scales offer a means to reanalyze PDQ-39 data from an ICF perspective and to study its health components using a widely available health status questionnaire for people with PD.
    07/2010; 2010:984673. DOI:10.4061/2010/984673
  • [Show abstract] [Hide abstract]
    ABSTRACT: The applicability of using an inert tracer gas to measure intestinal blood flow is investigated. The results from studies carried out to demonstrate that the pulmonary clearance of an inert noncombustible gas (helium) instilled into the colon changes predictably with colon blood flow (CBF) are presented. The results indicate that pulmonary clearance of the tracer gas follows expected changes in colon blood flow during hypoxia, hypovolemic hypotension,and vascular occlusion and correlates well with colon blood flow measured by radiolabeled microspheres
    Engineering in Medicine and Biology Society, 1989. Images of the Twenty-First Century., Proceedings of the Annual International Conference of the IEEE Engineering in; 12/1989
  • [Show abstract] [Hide abstract]
    ABSTRACT: Summary form only given. Functional decomposition is a process of representing a complex function as a function of functions with fewer variables. Earlier partition based functional decomposition tools represent the functions using r-partition. The r-partition representation is an abstract representation of the function and their memory requirements are super-exponential. An improved functional representation called ir-partition is proposed. The ir-partition representation is a complete representation of the function and requires less memory to store the functions. The main idea behind the ir-partition representation is to incorporate the values of the minterms corresponding to the variables (cubes). Hence, repeated access of the truth table is not necessary to read the value of the minterms. The computational time to calculate the ir-partition operations are three times greater than the computational time and memory requirement to calculate r-partition. However, the memory requirements for representing the function using ir-partition is half the memory requirement using the r-partition representation (abstract representation). Their partition representation also allows us to perform certain Partition Calculus operations implicitly. The representation has been implemented and tested with the MCNC benchmarks
    Computational Intelligence and Multimedia Applications, 2001. ICCIMA 2001. Proceedings. Fourth International Conference on; 02/2001