funktionsskal

Funktionsskal (Swedish for functional scale) is a generic term used in medicine, rehabilitation, and psychology to refer to instruments designed to quantify functional status in individuals. A functional scale typically aims to measure a person’s ability to perform activities of daily living and other functional domains such as mobility, self-care, communication, and cognitive function. Items describe specific tasks, and respondents or clinicians rate each item using ordered categories, often on a Likert-type scale or a yes/no/difficulty format. The item responses are combined into a total score, and in many cases domain scores are calculated to reflect different areas of function. The resulting score is used for baseline assessment, monitoring change over time, and evaluating treatment outcomes.

Functional scales vary in design and application. Some are clinician-rated (for example, scales used by therapists to assess ADL independence), others are patient-reported outcomes. They may be ordinal or interval in measurement properties, with many treated as interval scales in analysis. Reliability (inter-rater and test-retest) and validity (content, construct, criterion) are essential psychometric properties. Responsiveness to clinically important change and minimal clinically important difference are important concepts. Cross-cultural adaptation and linguistic validation are common when scales are used in different languages.

Examples of widely used functional scales include measures of activities of daily living such as the Barthel Index and the Katz ADL index, as well as broader functional measures like the Functional Independence Measure (FIM).