Reliability and validity of an objective structured clinical examination for physical therapy students

The purpose of this study was to examine the reliability and validity of an objective structured clinical examination (OSCE) for students in the first year of a 2-year physical therapy program. Forty-eight students were examined at eight stations in one of two duplicate OSCE circuits. The stations evaluated skills required for the management of persons with chronic musculoskeletal conditions. At each station, students were required to interact with patients, demonstrate techniques, or interpret observations. Checklists were used to score all stations, which had equal values. The associations among stations were examined using Pearson's correlations and Cronbach's alpha. A two-way analysis of variance (ANOVA) with repeated measures was used to determine differences among stations and between circuits. The validity of the OSCE was evaluated by determining the correlations between scores on the stations and performance in a subsequent clinical practicum. Correlations between stations were r = -0.14 to 0.33 and between stations and clinical performance were r = -0.28 to 0.27. Cronbach's alpha was 0.48. The ANOVA revealed significant differences among stations (F = 62.6, p = 0.000) but not between circuits (F = 1.8, p = 0.185). There was no significant interaction between circuit and station (F = 1.1, p = 0.356). There was poor internal consistency of the OSCE, and it did not predict clinical performance. Further research is required to determine if a larger number of stations can reliably and validly assess clinical skills of physical therapy students.