Validation of MSAT: an instrument to measure medical students' self-assessed confidence in musculoskeletal examination skills.

CONTEXT Self-assessment promotes reflective practice, helps students identify gaps in their learning and is used in curricular evaluations. Currently, there is a dearth of validated self-assessment tools in rheumatology. We present a new musculoskeletal self-assessment tool (MSAT) that allows students to assess their confidence in their skills in and knowledge of knee and shoulder examination. OBJECTIVES We aimed to validate the 15-item MSAT, addressing its construct validity, internal consistency, responsiveness, repeatability and relationship with competence. METHODS Participants were 241 Year 3 students in Newcastle upon Tyne and 113 Year 3 students at University College London, who were starting their musculoskeletal skills placement. Factor analysis explored the construct validity of the MSAT; Cronbach's alpha assessed its internal consistency; standardised response mean (SRM) evaluated its responsiveness, and test-retest, before and after a pathology lecture, assessed its repeatability. Its relationship with competence was explored by evaluating its correlation with shoulder and knee objective structured clinical examinations (OSCEs). RESULTS The MSAT was valid in distinguishing the 5 domains it intended to measure: clinical examination of the knee; clinical examination of the shoulder; clinical anatomy of the knee and shoulder; history taking, and generic musculoskeletal anatomical and clinical terms. It was internally consistent (alpha = 0.93), responsive (SRM 0.6 in Newcastle and 2.2 in London) and repeatable (intraclass correlation coefficient 0.97). Correlations between MSAT scores and OSCE scores Were weak (r < 0.2). CONCLUSIONS The MSAT has strong psychometric properties, thereby offering a valid approach to evaluating the self-assessment of confidence in examination skills by students. Confidence does not necessarily reflect competence; future research should clarify what underpins confidence.