Consultation competence in general practice: testing the reliability of the Leicester assessment package.

BACKGROUND: An acceptable assessment must be both valid and reliable; the face validity of the Leicester assessment package has already been established. AIM: This study set out to test the reliability of the Leicester assessment package, and the factors influencing it, when used by multiple assessors to assess performance in general practice consultations.
METHOD: Six randomly selected course organizer assessors simultaneously used the package to conduct independent assessments of the performance of five doctors of widely varying abilities in consultation with six simulated patients. The scores allocated were subjected to generalizability analysis.
RESULTS: The mean scores allocated for consultation performance of individual doctors ranged from 51% to 70%, with the lower scores being allocated to the less experienced doctors. Scores of each assessor across the cases were examined for internal consistency and five of the six assessors consistently scored the doctors with an alpha coefficient of the minimum accepted level of 0.80 or greater. The other assessor had a consistency of only 0.22. Measurements of consistency within cases between markers indicated that the first case produced unreliable results (alpha coefficient 0.25) but all other cases were scored consistently. Two independent assessors scoring eight consultations are the requisite numbers to achieve acceptable levels of reliability in a formal assessment process; seven consultations produce the minimum acceptable generalizability coefficient of 0.80 plus the first 'non-counting' consultation.
CONCLUSION: Required levels of reliability can be achieved when the package is used by multiple markers assessing the same consultations over a wide range of consultation performance. To achieve reliability only two hours of assessment time are required using the Leicester package compared with the previously regarded minimum of 32 hours. Although assessors can produce reliable scores with minimal training, intra-assessor reliability cannot be taken for granted and all assessors should be trained and calibrated before being sanctioned to conduct assessments, particularly for regulatory purposes. The Leicester assessment package has now been shown to be valid, reliable, feasible and easy to use in practice. It can, therefore, be recommended for use in both formative and summative assessment of consultation competence in general practice.