Q&A column

Editor: Frederick L. Kiechle, MD, PhD

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Q. Every month our anatomic pathology laboratory amends patient reports. Does the CAP have a benchmark for amended reports, such as how many are acceptable per month?

A.August 2022—CAP anatomic pathology checklist item ANP.12185 does not provide a benchmark for amended reports.¹ Amendment rates vary significantly based on practice setting; complexity of case mix; method of error detection (active versus passive); practice structure (mandated double-review before signout or not); preferences of pathologists, clinicians, and institutions regarding the taxonomy of errors and types of errors requiring amendment; and the structural capabilities of laboratory and hospital information systems.^2-4

Amendment rates range from 0.1 to 10 percent.^2-4 Therefore, the CAP accreditation requirement focuses on ensuring that the laboratory has a process to minimize patient harm from significant changes to reports instead of setting a numeric benchmark for amendments.

Checklist item ANP.12185 states, “The laboratory issues an amended report and promptly notifies the responsible clinician(s) when there are changes to reports that significantly affect patient care.” The report must include the reason for the amendment, who made the change, who was notified of the revision, and the date. Notably, the responsible clinician may not be the clinician who had ordered the tests if the amendment is issued after a significant time lag between the original and the corrected report.⁵ Furthermore, there is disagreement as to whether communication to a surrogate in a physician office is acceptable for a significant and unexpected change to a diagnosis.⁶

That said, quality improvement plans in anatomic pathology should monitor fractional amendment rates (for example, errors due to misinterpretation and misinformation) and have rate- and rule-based triggers to detect failures in the system as soon as possible. Rate-based triggers are useful for monitoring process flows and identifying system-based breakdowns, which in some cases may be upstream of the pathology department. For example, implementing computerized order-entry systems in operating rooms may increase misinformation amendment rates due to autopopulation errors from entering ICD-10 code-based history or from workflow changes, such as transferring order entry from physicians to operating room nurses.⁷ In these instances, the corrective action plan requires an institutional-level intervention.

Rule-based triggers are more effective for monitoring and preventing harm from high-severity or unusual failures. Institutions should define rule-based triggers based on their case mix and practice parameters. A common rule-based trigger is mandated review of cases with primary level misinterpretation errors where a diagnosis is changed from negative to positive or vice versa. While such discrepancies often have a ready explanation (for example, variable diagnostic cut-offs among experts), these can signal cognitive or proficiency deterioration in a previously high-performing pathologist.

We do not recommend using the term “diagnostic error” for a misinterpretation error. The CAP uses the term “interpretive error.”⁴ This is because the seminal report by the National Academies of Sciences, Engineering, and Medicine titled Improving Diagnosis in Health Care defines diagnostic error as any error that leads to a diagnosis not being accurate or communicated to the patient in a timely manner.⁸ Therefore, virtually all pathology errors are diagnostic errors. Even a misinformation error in which data are entered incorrectly, leading to a delay in the patient receiving a diagnosis, is a diagnostic error.