Background: Amended surgical pathology reports record defects in the process of transforming tissue specimens into diagnostic information.
Objective: Systematic study of amended reports tests 2 hypotheses: (a) that tracking amendment frequencies and the distribution of amendment types reveals relevant aspects of quality in surgical pathology's daily transformation of specimens into diagnoses and (b) that such tracking measures the effect, or lack of effect, of efforts to improve surgical pathology processes.
Materials and Methods: We applied a binary definition of altered reports as either amendments or addenda and a taxonomy of defects that caused amendments as misidentifications, specimen defects, misinterpretations, and report defects. During the introduction of a LEAN process improvement approach—the Henry Ford Productions System—we followed trends in amendment rates and defect fractions to (a) evaluate specific interventions, (b) sort case-by-case root causes of misidentifications, specimen defects, and misinterpretations, and (c) audit the ongoing accuracy of the classification of changed reports. LEAN is the management and production system of the Toyota Motor Corporation that promotes continuous improvement; it considers wasted resources expended for purposes other than creating value for end customers and targets such expenditures for elimination.
Results: Introduction of real-time editing of amendments saw annual amendment rates increase from 4.8/1000 to 10.1/1000 and then decrease in an incremental manner to 5.6/1000 as Henry Ford Productions System-specific interventions were introduced. Before introduction of HFPS interventions, about a fifth of the amendments were due to misidentifications, a 10th were due to specimen defects, a quarter due to misinterpretation, and almost half were due to report defects. During the period of the initial application of HFPS, the fraction of amendments due to misidentifications decreased as those due to report defects increased, in a statistically linked manner. As HFPS interventions took hold, misidentifications fell from 16% to 9%, specimen defect rates remained variable, ranging between 2% and 11%, and misinterpretations fell from 18% to 3%. Reciprocally, report defects rose from 64% to 83% of all amendment-causing defects. A case-by-case study of misidentifications, specimen defects, and misinterpretations found that (a) intervention at the specimen collection level had disappointingly little effect on patient misidentifications; (b) standardization of specimen accession and gross examination reduced only specimen defects surrounding ancillary testing; but (c) a double review of breast and prostate cases was associated with drastically reduced misinterpretation defects. Finally, audit of both amendments and addenda demonstrated that 10% of the so-called addenda actually qualified as amendments.
Discussion: Monitored by the consistent taxonomy, rates of amended reports first rose, then fell. Examining specific defect categories provided information for evaluating specific LEAN interventions. Tracking the downward trend of amendment rates seemed to document the overall success of surgical pathology quality improvement efforts. Process improvements modestly decreased fractions of misidentifications and markedly decreased misinterpretation fractions. Classification integrity requires real time, independent editing of both amendments (changed reports) and addenda (addition to reports).