Reliability of Evaluation in Physical Therapy Studies

Abstract

Recently, evidence based physical therapy (EBPT) has become topical. The items of importance in examinations for EBPT are the outcome measures, however, there are several problems with outcome measures, and one of these is reliability. Here, by reliability, we mean inter-rater reliability and inter-class reliability. Pearson's product-moment correlation coefficent, for example, is often cited as an expression of reliability, but in this study we discuss the intra-class correlation coefficient and outline methods for determining inter- and intra- rater reliability