Pathologists typically become aware of making a serious diagnostic error about once a year, with an overall diagnostic error rate of 3-4% and clinically significant error rate of 1-2%. Errors are rarely due to incompetence and can be caused by factors like heavy workload. Pathologists should engage in continuing education, audit their performance, and communicate effectively with colleagues to help reduce errors. Quality improvement systems like clinical audits, multidisciplinary team meetings, and external reviews can help detect errors and improve diagnostic standards.

1. ERROR TRAPPING AND
ERROR AVOIDANCE
IN
HISTOPATHOLOGY

2. Error rates in diagnostic
histopathology
 A typical histopathologist becomes aware of having
made a serious diagnostic error about once a year
 Overall diagnostic error – 3 to 4%
 Clinically significant error – 1 to 2%
 “Zero error rate” – cannot be achieved even with use of
automated re-screening devices

3. Classification of diagnostic errors
Category 1 A diagnostic error which would have a
definite influence on clinical management
and possible outcome
Category 2 A diagnostic misinterpretation or oversight
which has the potential to affect clinical
management or outcome
Category 3 A minor discrepancy of disease
categorization likely to be of little clinical
significance

4. What sort of errors are
made?
 Oversight errors
 Misinterpretation errors
 Errors are rarely due to incompetence, lack of
knowledge or inability to do the work
 Other factors – heavy workload
 Areas where pathologists tend to make more mistakes –
lymphoma, melanoma, prostate needle biopsies.
 Physical impairment of visual function, colour blindness
 There is no evidence that pathologists with inability to
distinguish subtle colour hues perform less well than
others

5. Individual professional
performance
Pathologists should be
 Up-to-date with their specialist knowledge
 Right skills and attitude to manage services
 Communicate effectively
 Audit their performance
 Re – validation or re-licensing process

6. Good pathology practice
Pathologists should
 Assure the quality of clinical advice given and
associated record keeping
 Ensure the quality and timeliness of pathology reports
and clinical advice
 Undertake routine review (audit) of a sample of clinical
cases / reports in selected areas
 Show that individual diagnostic patterns compare
favourably with their peers
 Offer appropriate treatment, management or diagnostic
decision making
 Describe the distribution of their workload and case-mix

7. Professional behaviour and
working relationships
All pathologists must
 Be available and willing to communicate and discuss
clinical and professional issues with colleagues
 Know their own diagnostic limitations as demonstrated
by their referral patterns
 Participate in clinicopathological discussions or
multidisciplinary team meetings
 Work well in a team
 Ensure that there are no tensions relating to private
practice, coroner’s work or outside commitments

8. Identifying poor performance
 Identifying underperforming pathologists
 Errors should not be judged in isolation but in the
context of pathologist’s overall performance
 The performance of doctors should be assessed using
Cambridge model approach, which applies a range of
methods and indicators that take into account both
individual competence and day-to-day work context

9. Factors leading to increased risk of
errors and poor performance in
histopathology
 Conditions of work, staffing and workload
 Locum working in unfamiliar surroundings
 Potential constraints on performance in the laboratory
 Low volume work or case-mix and where the pathologist
may be working outside his or her expertise
 Isolated or single-handed practice

10. Clinical audit
 Reliable and systematized audit practice
 Audit is used to monitor diagnostic and service
standards and identify and prevent errors
 Audit and peer review are useful in reducing
inaccuracies in reports

11. Specialist reporting
 Specialist reporting reduces the number of errors made

12. Quality improvement systems
Type of review Process
Intradepartmental consultation Review of selected cases by colleagues
Intra- operative consultation
(frozen section)
Review of frozen section diagnosis in the light of
final paraffin wax section diagnosis
Random case review
Re-reporting of a random sample from all cases
submitted
Clinical indicator audit
Cases selected on a clinical basis checked over
a given period to ensure consistency in
diagnosis and reporting
Multidisciplinary Team Meeting
Comparison of presented diagnosis against
reported diagnoses
Inter- institutional review
Comparison of local diagnoses with outside
review diagnoses
Reporting patterns
Comparison of pattern of reporting among group
of pathologists

13. Quality improvement systems
Type of review Process
Workload profile Audit of busy and quiet periods
Turnaround times Audit of time taken to produce reports
Specimen adequacy
Monitoring identification and processing of
specimens
Lost specimens Monitoring number of lost specimens
Histology quality control
Assessment of times of delivery of slides and
quality of staining

14. Other methods to detect
errors
 Consistency in reporting
 Patterns of error -analysis of diagnostic pattern( use of
inappropriate or inconsistent terminology)
 Case referral
 Multidisciplinary team meetings
 Use of guidelines and datasets
 External quality assurance
 Risk management
 Adverse incident reporting
 Hindsight bias

15. Conclusions
 The detection of errors and error avoidance depends upon
individuals practising to the highest standards by ensuring
they are up-to-date
 Pathologists should be willing to monitor their own
performance, know their limitations and communicate with
peers
 Pathologists should engage in the process of developing
standardized approaches to macroscopic description,
specimen sampling, special stains and histological reporting
 The laboratories in which pathologists work should have
systematized method of audit, quality improvement and IT
systems to analyze the data and to identify poor performance
at an early stage

16. Thank you…
To make no mistakes is not in the power of
man; but from their errors and mistakes
the wise and good learn wisdom for the
future.