[Norwegian Functional Scale--a new instrument in sickness certification and disability assessments]

Functional assessments are requested in the follow-up of sick-listed persons and for disability benefit decisions. We describe the development of the Norwegian Functional Scale that may assist health providers in getting an insight into patients' self-evaluated functioning.

An expert panel developed a 40-item functional scale to be completed by sick-listed persons. The scale was based on the WHO Classification of Functioning, Disability, and Health (ICF). In April 2001 the scale, SF-36, and COOP/WONCA charts were tested on 798 persons who had been sick-listed for six weeks. Factor analysis was used to group single items into functional dimensions. Correlation analysis was applied for validity testing against the established instruments.

48% filled in the questionnaire. The factor analysis confirmed four physical dimensions of functioning (walking/standing, holding/handling, lifting/carrying and sitting), and three mental (coping, communicating and senses). The scale correlated significantly with corresponding dimensions in SF-36, COOP/WONCA and a question on ability to go back to work.

The Norwegian Functional Scale showed considerably reduced functioning in sick-listed persons. The scale appears to be valid.