Development and testing of a patient questionnaire regarding symptoms and outcomes of rehabilitation
Reanalyses of large datasets and theoretical considerations showed that the patient questionnaire "Indicators of Reha-Status" ("Indikatoren des Reha-Status", IRES, Version 2) needed reworking at some points. The new version IRES-3 was developed according to a theoretical model of rehabilitation based on the ICF (International Classification of Functioning, Disability and Health) as well as of reliable elements of the IRES-2. In addition, the results of expert meetings to define therapy goals in medical rehabilitation were integrated into the development.
The IRES-3 was evaluated regarding the questionnaire quality criteria in 453 rehabilitands from seven indication areas and the results cross-validated at an external sample. The dimensional structure was tested in confirmatory factor analyses (LISREL).
With the exception of a few scales, the IRES-3 possesses good values regarding item difficulty, floor and ceiling effects, internal consistency and test-retest-reliability. The convergent validity could be confirmed in comparisons with the SF-36 and HADS with correlations between 0.50 and 0.70 between the relevant scales. The sensitivities to change are comparable, in a few cases somewhat higher than those of the SF-36. Analyses regarding construct validity and dimensional structure of the questionnaire suggested eight dimensions for the areas of somatic, mental, daily living, occupational and the social functioning, pain, coping and one dimension "Information and health behaviour". The dimensional structur of the IRES-3 is theoretically well interpretable and empirically sound.
In 2001, a standard sample representative for the German general population was drawn, the data of which allow a norm-based interpretation of the scale values of individual rehabilitands.
The Der IRES-3 is avaliable on the website of the Department of Quality Management and Social Medicine at the University Hospital Freiburg, Germany, including a computer programme for data entry and analysis.
Duration: 1999 – 2002
Funding: Verband Deutscher Rentenversicherungsträger (VDR) and German Federal Ministry for Education, Science, Research and Technology (BMBF) in the framework of the joint funding programme "Rehabilitation sciences" (Project No. 01 0997 96 08).
Project lead: Christian Zwingmann/Bernhard Bührlen at Hochrheininstitut für Rehabilitationsforschung, Bad Säckingen
Bührlen, B., Gerdes, N. & Jäckel, W.H. (2003). IRES - Indikatoren des Reha-Status. In J. Schumacher, A. Klaiberg & E. Brähler (Hrsg.), Diagnostische Verfahren zu Lebensqualität und Wohlbefinden (Diagnostik für Klinik und Praxis, Bd. 2, S. 180-183). Göttingen: Hogrefe.
Bührlen, B., Gerdes, N. & Jäckel, W. H. (2005). Entwicklung und psychometrische Testung eines Patientenfragebogens für die medizinische Rehabilitation (IRES-3). Die Rehabilitation, 44, 63-74.