Each year we assess the communication skills of 240 students via a final year OSCE lasting 6 days. The communication scenario spreads to students taking the examination later in the week. Ironically, this can have a negative impact on these “more knowledgeable” students. 

To minimize the impact of this scenario-sharing we wanted to check the reliability of one OSCE with two scenarios.  

Two communication skills stations were designed for our November 2016 formative OSCE exam; station 1 was a cat needing castrating and station 2 was a coughing horse. For the coughing horse we created two different conditions with different histories. The key elements of history and the mark scheme for obtaining these for each horse was the same. Two actors were involved for the duration of the 6-day OSCE, and to reduce fatigue, they changed stations half-way through each day.  Each actor played a different horse client. Comparisons of marks achieved by students who faced each actor for each station were carried out. Statistical significance was set at 0.05.   

The overall marks obtained by students for each of the two horse scenario were not significantly different (p=0.22). However, differences were observed in the marking of particular elements of the history, highlighting areas for either scenario improvement, or actor training. 

An OSCE station with two scenarios played by two actors can provide a reliable test of student communication skills. However, care needs to be taken in designing the scenarios and in training the actors to ensure equivalence.  

LIVE Centre for Excellence, Royal Veterinary College, LONDON UK