An exploration of the inter- and intra-rater reliability of the Bath Ankylosing Spondylitis Metrology Index.

The aim of this study was to explore the inter- and intra-observer reliability of the Bath Ankylosing Spondylitis Metrology Index (BASMI) across raters from different clinical centres using a consensus-based standardised approach to assessment. One hundred thirty BASMI assessments were completed on the same day using a partially balanced incomplete block design. Thirteen physiotherapists from 10 hospitals assessed 26 participants (19 patients, 7 healthy volunteers).