Does observation add to the validity of the long case?

Background A London medical school final MBBS examination for 155 candidate s. Objective To investigate whether observing the student-patient interaction in a history taking (HT) long case adds incremental information to the trad itional presentation component. Design A prospective study of a HT long case which included both examiner o bservation of the student-patient interview (Part 1) and traditional presen tation to different examiners (Part 2). Checklist and global ratings of bot h parts were compared. Examiners were paired to estimate inter-rater reliab ility. The students also took a 20 station Objective Structured Clinical Ex amination (OSCE). Outcome measures Correlation of (I) examiner ratings for observation and pr esentation of the HT long case (II) examiner pair ratings and (III) stepwis e regression analysis of scores for the HT long case with OSCE scores. Results Seventy-five (48.4%) candidates had two examiner pairs marking thei r case history. Observation and presentation scores correlated poorly (chec klist 0.38 and global 0.33). Checklist and global scores for each part corr elated at higher levels (observation 0.64 and presentation 0.61). Inter-rat er reliability correlations were higher for observation (checklist 0.72 and global 0.71) than for presentation (checklist 0.38 and global 0.60). When HT long case scores were correlated with OSCE scores, using stepwise regres sion, global presentation scores showed the highest correlation with the OS CE score (0.36) and the global observation score contributed a further 12% to the correlation (0.50). Conclusion Observation of history taking in a long case appears to measure a useful and distinct component of clinical competence over and above the c ontribution made by the presentation.