[Validation of the computerized adaptive assessment procedure RehaCAT related to functional and mental strain in a sample of rehabilitation patient suffering from musculoskeletal diseases]. / Validierung der computeradaptiven Assessmentprozedur RehaCAT hinsichtlich funktionaler und psychischer Belastungen bei Rehabilitanden mit muskuloskelettalen Erkrankungen.

The Rasch-based, computerized adaptive assessment procedure RehaCAT allows to assess the ICF-oriented dimensions "activities in daily living", "functionality upper extremities" and "functionality lower extremities" as well as "depression" economically and reliably in orthopaedic rehabilitation patients. This validation study aimed at analyzing the multivariate association of the RehaCAT dimensions with the commonly applied ODI, SF-12 and HADS-D assessment scales in a sample of rehabilitation patient suffering from musculoskeletal diseases (spine disease: 58,7%). By means of structural equation modeling high convergent and divergent validity of the RehaCAT dimensions could be proven in a sample of N=184 rehabilitation patients (71,2% inpatient and 28,8% outpatient). In the resulting model between 41% (functionality upper extremities) and 76% (activities in daily living) of the RehaCAT dimensions could be explained mainly by the theoretical assumed predictor constructs. Because of its psychometric foundation, economy and validity, the RehaCAT provides an optimal basis to assess central ICF-oriented constructs in orthopaedic rehabilitation.

[Confirmatory analysis of the dimensional structure of the ODI, the SF-12 and the HADS-D scales in a sample of rehabilitation patients with musculoskeletal diseases]. / Konfirmatorische Prüfung der dimensionalen Struktur des Oswestry Disability Index, des SF-12 und der HADS-D bei Rehabilitanden mit muskuloskelettalen Erkrankungen.

This study aimed at confirmatory testing the factorial structure of the established assessment instruments ODI, SF-12 and HADS-D by means of structural equation modeling in a sample of n=184 rehabilitation patients with musculo-skeletal diseases. According to local and global fit indices for each instrument an acceptable to good fit to the underlying theoretical model could be verified. For the ODI as well as for the HADS-D only single weak item-construct associations indicated shortcomings in the assumed model structure. For the SF-12 the constructs "physical health" and "mental health" could be validated after defining the additional first order factors "role - physical", "role - emotional" and "well-being", respectively. In general, the study findings proved the factorial validity of the instruments. Additionally, specific measurement properties on item and structural level could be identified which might enhance the understanding of construct definitions in rehabilitation patients with musculoskeletal diseases.

[Adaptive testing in rehabilitation: a way to economic assessment of patients' attributes]. / Adaptives Testen in der Rehabilitation - ein Weg zur ökonomischen Erhebung von Patientenmerkmalen*

For diagnostics and outcome measurement in clinical rehabilitation a multitude of questionnaires is used. In order to gain comparability of the diagnostic findings, generally, the same information is gathered of all patients, regardless of their state of health or how severely ill they are, by using identical groups of items. In this kind of assessment it is, however, problematic that (a) the assessment instrument usually only allows for adequate and reliable diagnostics of patients who suffer from injuries or illnesses of medium severity, and (b) that an uneconomic data collection is required because of an extensive set of items which may in individual cases be uninformative and unnecessary. This article shows how data assessment can be adjusted to the individual handicaps of the patient by using adaptive or tailored testing. Thus it can be ensured that the testing becomes more economical and results more precise. Furthermore, a high acceptance by the patients participating in the data collection can be achieved, as the test items submitted fit the ability of the patients adequately. Yet, adaptive test systems require a complex and very careful psychometrical development of the assessment procedure in such a way that in spite of presenting different items to patients, diagnostic outcomes are comparable between patients and for different points in time (e. g., pre-post comparison). This article shows the steps of development that have to be accomplished in order to set up a psychometrically sound adaptive test procedure. Moreover, it shows how its usage in the area of medical rehabilitation can be profitable for handlers and patients.