How to assess the reliability of measurements in rehabilitation

To evaluate the effects of rehabilitation interventions, we need reliable measurements. The measurements should also be sufficiently sensitive to enable the detection of clinically important changes. In recent years, the assessment of reliability in clinical practice and medical research has developed from the use of correlation coefficients to a comprehensive set of statistical methods. In this review, we present methods that can be used to assess reliability and describe how data from reliability analyses can aid the interpretation of results from rehabilitation interventions.