gms | German Medical Science

Background: To evaluate the effects of rehabilitation measures, the indirect measurement of change is considered a clinical standard. In non-controlled studies, the occurrence of patients' response shifts (RS) from the first to the second measurement point may lead to a falsification of the true rehab effects in the context of written questionnaires.

Aim: So it was the aim of the present pre-experimental study to determine the RS and its possible influence on the rehabilitation outcome of patients with knee complaints.

Method: To control RS, 99 male patients (51.2 years, BMI: 29.2) with degenerative knee complaints underwent a 3-week outpatient evidence-based rehabilitation program [1]. At the beginning (T1) and at the end (T2) of rehabilitation, patients were extensively investigated. The determination of the RS based on written questionnaires and carried out using the then-test.

Results/findings: In T2, there was a significant improvement in all parameters investigated. The RS was proven in the form of an over- (SF-36, WOMAC) and underestimation (PACT) with small effect sizes and a poor clinical significance, which corresponds to the data from the literature. In addition, the validity of the RS was limited by confounders such as present state and recall bias, heterogeneous alignment of the data, and differences in patient interests and expectations.

Discussion and conclusions: It is to be discussed whether the RS should not be interpreted as an expression of a desired successful disease coping of the patients [2].