An assessment of the operation of an external quality assessment (EQA) scheme in histopathology in the South Thames (West) Region: 1995-1998

Aims-To describe the design and organisation of a voluntary regional extern al quality assessment (EQA) scheme in histopathology, and to record the res ults obtained over a three year period. Methods-A protocol is presented in which circulation of EQA slides alternat ed with teaching sessions. Procedures for the choice of suitable cases, eva luation of submitted diagnoses, and feedback of results to participants are described. The use of teaching sessions, complementary to the slide circul ations, and dealing with current diagnostic problems is also outlined. Results-Participation rates in the nine slide circulations varied between 6 6% and 89%, mean 85%. Overall scores were predictably high but 4% of return s, from 10 pathologists, were unsatisfactory. These low scores were typical ly isolated or intermittent and none of the participants fulfilled agreed c riteria for chronic poor performers. Conclusions-This scheme has been well supported and overall performances ha ve been satisfactory. The design was sufficiently discriminatory to reveal a few low scores which are analysed in detail. Prompt feedback of results t o participants with identification of all "incomplete" and "wrong" diagnose s is essential. Involvement of local histopathologists in designing, runnin g, and monitoring such schemes is important.