Prospective and Retrospective Measurement of Change in Outpatient Rehabilitation for Musculoskeletal and Cardiac Diseases

The indirect measurement of change is a prospective measurement method in which the differences between the levels at the beginning and end of an intervention are used as indicators for the changes that have taken place. In the direct measurement of changes, the changes are regarded in retrospect by asking an assessor (e.g. the patient) to directly evaluate the changes that have taken place. In this study, these two methods of measuring changes are compared empirically in an assessment of the results Of Outpatient rehabilitation for musculoskeletal and cardiac diseases. During a pilot project for the development of a quality assurance program for outpatient rehabilitation, data were compiled from 12 outpatient rehabilitation centers on a total of 749 patients with musculoskeletal disease and 322 patients with cardiac disease. The instruments used to compile this data were the IRES questionnaire and the newly developed questionnaire for the retrospective measurement of change (Retro questionnaire), based on the scales of the IRES questionnaire items. The items of the Retro questionnaire were accepted by the patients and showed good to very good reliability values in the scales. The distribution properties are also good; there are no pronounced ceiling or floor effects. The sensitivity to change and the factorial structure of the Retro questionnaire can also be described as good. However, there are some doubts as to the construct validity. The correlation to the prospective measurement of change is generally very low: regression analyses show that the retrospective assessment of change is affected considerably by the status after rehabilitation as well as the psychological condition and acceptance of the disease, and in only a few cases by the status at admission. Retrospective measurement of change is suitable for an economical assessment of rehabilitation results if the results can be limited to a relatively global assessment and the evaluation of change is not used to make comparisons between rehabilitation centers. If the results of rehabilitation are to be evaluated in detail or comparisons made between various rehabilitation centers, the prospective measurement of changes appears to be more useful.