A questionnaire-based survey of errors in diagnostic histopathology throughout the United Kingdom

To obtain a crude estimate of the rate at which consultant histopathologists become aware of errors in their work, and to gather information about the circumstances under which errors are made.

A postal questionnaire was sent to all consultant histopathologists (1021) in the United Kingdom.

There was a 19.8% response to the questionnaire (202 returned). 119 pathologists reported 244 errors, 82 from within the preceding year. 42% of these errors had affected patient management. Pathologists usually blamed human error or excessive workload; however, data analysis did not reveal an excess of responses from laboratories with heavy workloads. A disproportionately large proportion of errors appear to be made in samples from the lymphoreticular system and by locum consultant pathologists.

This study undoubtedly suffered from reporting bias, but the figures suggest that a typical pathologist probably becomes aware of having made a serious diagnostic error approximately once per year. A larger, more systematic study of the circumstances under which errors are likely to occur appears to be justified but would require significant resources because of the large sample size required.