An evaluation of the effectiveness of a videotape programme on interobserver reliability in outcome assessment for osteoarthritis

Aims. A study was designed to assess the effects of a standardized instructional videotape on training senior medical students to acceptable levels of reliability in performing several commonly used observer dependent outcome measures in patients with osteoarthritis (OA). Methods. During a single day, six third-year medical students independently examined six patients with OA in predetermined order using a Latin Square design, before and after viewing a standardized videotape demonstrating 13 examination techniques. Reliability coefficients were calculated based on variance components of the analysis of variance (ANOVA) table. Results. Prestandardization reliability coefficients were < 0.80 for seven measures. Coefficients for the performance of knee goniometry were uniformly low. Following the intervention, all but four reliability coefficients were ≥ 0.93. Conclusions. For many measures, high levels of interobserver agreement were noted prior to viewing the instructional videotape. This may represent the success of undergraduate clinical skills training programmes, or it may be the result of having reviewed an illustrated instructional text just prior to the initial patient examinations. The notable exception was knee goniometry. Despite apparent familiarity with the technique, prestandardization reliability coefficients were very low. However, following the intervention, all coefficients improved dramatically, two-thirds achieving very high levels. These data suggest that skills development in senior medical students is not uniform and that, while reliability is high for many, the assessment of knee range of movement can be improved by viewing an instructional videotape