[Outcome measurement in musculoskeletal diseases: recommendation for a core set of scales for use in rehabilitation]

By application of a standardized core set of outcome measurement instruments, comparison between studies as well as meta-analyses in rehabilitation research can be facilitated. The German Society for Rheumatology has commissioned its working group on rehabilitation with the development of a proposal for such a core set of outcome measurement instruments. In a first step, dimensions for outcome measurement in rehabilitation were defined by a group of experts which represented rehabilitation hospitals, acute care hospitals, and research groups specialized in outcome measurement. The Delphi method was used in a multiple step consensus process. In a second step, instruments and procedures to operationalize the relevant dimensions were chosen. Reliability, validity, sensitivity to change, and practicability were used as criteria for selecting measurement instruments. The main intention of the proposed core set of outcome measurement instruments is to facilitate the processes of planning and carrying out rehabilitation research studies. Furthermore, the proposed instruments can be used for clinical documentation systems as well as for internal or external quality assurance programs.

[The North American Spine Society Lumbar Spine Outcome Assessment Instrument: translation and psychometric analysis of the German version in rehabilitation patients with chronic back pain]

The "Lumbar Spine Outcome Assessment Instrument", developed by the North American Spine Society (NASS), was translated into German. Its psychometric properties were tested in a group of rehabilitation patients with chronic, unspecific back pain, and in a comparison group of patients in cardiologic rehabilitation. With a Cronbach's alpha of 0.92, internal consistency was high. Principal component analysis revealed that the German version of the NASS instrument surveys the factors "back pain", "neurologic symptoms", and "impairments". A strong correlation with other measures of functional impairment (FFbH-R, IRES) indicates a high concurrent validity of the NASS instrument. After three weeks of inpatient rehabilitation, sensitivity to change could be demonstrated for the summary score of the instrument. This significant change was primarily due to moderate effects in the factor "back pain". In our study population, the factor "impairments" did not show a significant change. On the basis of these results, the German version of "The North American Spine Society Lumbar Spine Outcome Assessment Instrument" can be described as a reliable and valid instrument for measuring back pain, related neurologic symptoms, and back pain-induced impairments in rehabilitation patients. Because the factor "impairments" is not sensitive to change within three weeks of rehabilitation, the instrument is only partly suitable for measuring short-term outcome in rehabilitation patients. Further research is needed to determine if the instrument is useful for middle- and long-term outcome measurement in rehabilitation.