Related Experiment Video
Updated: Jun 22, 2026

Measuring the Functional Abilities of Children Aged 3-6 Years Old with Observational Methods and Computer Tools
Published on: June 20, 2020
Items from patient-oriented instruments can be integrated into interval scales to operationalize categories of the
Alarcos Cieza1, Roger Hilfiker, Annelies Boonen
1ICF Research Branch, WHO Collaborating Center for the Family of International Classifications, German Institute of Medical Documentation and Information, IHRS, Ludwig-Maximilian University, Munich, Germany.
Objective:
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.
Study Design And Setting:
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.
Results:
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.
Conclusion:
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.
Related Concept Videos
Nursing Interventions II: Selecting and Classifying the Nursing Interventions
Ordinal Level of Measurement
Data measured using an ordinal scale are similar to nominal scale data, but there is one major difference. The ordinal scale data can be ordered. An example of ordinal scale data is a list of the top five national parks in the...
Interval Level of Measurement
Data measured using the interval scale are similar to ordinal level data because they have a definite arrangement. However, in the interval level of measurement, the differences between data values are meaningful even though the data does not have a starting point.
Temperature is measured using the interval scale. It is measurable data, and the difference between the...
Classification of Illness
An illness is a response to a disease in which the person's level of functioning is changed compared with a previous level. The general classification of illness includes acute and chronic.
Acute illness is severe and...
Dimensions of Health and Illness
Methods of Documentation III: PIE
