Frederick A. Meier

Errors in Thyroid Gland Fine-Needle Aspiration

Scant published data exist on redesigning pathology practice based on error data. In this first step of an Agency for Healthcare Research and Quality patient safety project, we measured the performance metrics of thyroid gland fine-needle aspiration, performed root cause analysis to determine the causes of error, and proposed error-reduction initiatives to address specific errors. Eleven cytologists signed out 1,543 thyroid gland aspirates in 2 years, and surgical pathology follow-up was obtained in 364 patients. Of the 364 patients, 91 (25.0%) had a false-negative diagnosis and 36 (9.9%) a false-positive diagnosis. Root cause analysis showed that major sources of error were pre-analytic (poor specimen quality) and analytic (interpretation of unsatisfactory specimens as nonneoplastic and lack of diagnostic category standardization). We currently are evaluating the effectiveness of error reduction initiatives that target pre-analytic and analytic portions of the diagnostic pathway.

Error Detection in Anatomic Pathology

OBJECTIVES To define the magnitude of error occurring in anatomic pathology, to propose a scheme to classify such errors so their influence on clinical outcomes can be evaluated, and to identify quality assurance procedures able to reduce the frequency of errors. DESIGN (a) Peer-reviewed literature search via PubMed for studies from single institutions and multi-institutional College of American Pathologists Q-Probes studies of anatomic pathology error detection and prevention practices; (b) structured evaluation of defects in surgical pathology reports uncovered in the Department of Pathology and Laboratory Medicine of the Henry Ford Health System in 2001-2003, using a newly validated error taxonomy scheme; and (c) comparative review of anatomic pathology quality assurance procedures proposed to reduce error. RESULTS Marked differences in both definitions of error and pathology practice make comparison of error detection and prevention procedures among publications from individual institutions impossible. Q-Probes studies further suggest that observer redundancy reduces diagnostic variation and interpretive error, which ranges from 1.2 to 50 errors per 1000 cases; however, it is unclear which forms of such redundancy are the most efficient in uncovering diagnostic error. The proposed error taxonomy tested has shown a very good interobserver agreement of 91.4% (kappa = 0.8780; 95% confidence limit, 0.8416-0.9144), when applied to amended reports, and suggests a distribution of errors among identification, specimen, interpretation, and reporting variables. CONCLUSIONS Presently, there are no standardized tools for defining error in anatomic pathology, so it cannot be reliably measured nor can its clinical impact be assessed. The authors propose a standardized error classification that would permit measurement of error frequencies, clinical impact of errors, and the effect of error reduction and prevention efforts. In particular, the value of double-reading, case conferences, and consultations (the traditional triad of error control in anatomic pathology) awaits objective assessment.

Evaluation of a Microarray-Based Assay for Rapid Identification of Gram-Positive Organisms and Resistance Markers in Positive Blood Cultures

ABSTRACT Rapid identification of pathogens directly from positive blood cultures can play a major role in reducing patient mortality rates. We evaluated the performance of the Verigene Gram-Positive Blood Culture (BC-GP) assay (Nanosphere Inc., Northbrook, IL) for detection of commonly isolated Gram-positive organisms as well as associated resistance markers from positive blood cultures. Positive blood cultures (VersaTREK; Trek Diagnostic Systems, Independence, OH) from 203 patients with Gram-positive organism infections were analyzed using the BC-GP assay within 12 h for the detection of 12 different organisms, including staphylococci, streptococci, and enterococci, as well as for the presence of 3 resistance markers (mecA, vanA, and vanB). Results were compared to those of routine laboratory methods for identification and susceptibility testing. For identification of organisms and detection of resistance markers in 178 monomicrobial positive blood cultures, the BC-GP assay showed 94% and 97% concordance, respectively, with routine methods. After 25 polymicrobial cultures were included, the results showed 92% and 96% agreement for identification and resistance markers, respectively, for a total of 203 positive cultures. In 6/25 polymicrobial cultures, at least 1 isolate was not detected. Concordance levels for detection of major pathogens such Staphylococcus aureus (n = 45) and enterococci (n = 19) were 98% and 95%, respectively. Agreement levels for detection of resistance markers such as mecA and vanA/B were 92% and 100%, respectively. The BC-GP assay is capable of providing rapid identification of Gram-positive cocci as well as detection of resistance markers directly from positive blood cultures at least 24 to 48 h earlier than conventional methods.

Mislabeling of Cases, Specimens, Blocks, and Slides A College of American Pathologists Study of 136 Institutions

CONTEXT Accurate specimen labeling is a major patient-safety initiative by the Joint Commission and the College of American Pathologists. Inadequate specimen labels have led to patient injury from wrong patient diagnosis, wrong side treatment, and delay in diagnosis. OBJECTIVES To quantify the rates of mislabeled cases, specimens, blocks, and slides and to identify the sources of error and the ways in which errors are detected. DESIGN In this voluntary-subscription Q-Probes study, participants prospectively reviewed surgical pathology cases for 8 weeks or until 30 errors (mislabeled cases, specimens, blocks, and slides) were identified. Information collected on each labeling error included the work location where the defect occurred, what was mislabeled, the number of items affected, the point of detection, and the consequences of the mislabeling error, along with institutional demographics and practice. The rates of mislabeled cases, specimens, blocks, and slides were tested for association with institutional demographics and practice variables. RESULTS Of the 136 institutions providing information on a total of 1811 mislabeling occurrences, the overall mislabeling rates per 1000 were 1.1 cases, 1.0 specimen, 1.7 blocks, and 1.1 slides. Of all mislabeling events, 27.1% were cases, 19.8% specimens, 25.5% blocks, and 27.7% slides. The work locations at which the errors occurred were 20.9% before accessioning, 12.4% at accessioning, 21.7% at block labeling, 10.2% during gross pathology, and 30.4% at tissue cutting. Errors were typically detected in the first or second steps immediately following the error. Lower mislabeled slide rates were associated with continuous individual case accessioning and use of formal checks at accessioning. Routinely including a statement in the gross description that the specimen is labeled with the patients name and is properly identified was also associated with lower rates of specimen mislabeling. The errors were corrected before reports were issued 96.7% of the time; for 3.2% of errors, a corrected report was issued. In 1.3% of error occurrences, participants gauged that patient care was affected. CONCLUSIONS This study quantified mislabeling rates across 136 institutions of cases (0.11%), specimens (0.1%), blocks (0.17%), and slides (0.11%). Errors in labeling appear nearly equally throughout the system of accessioning, gross pathology processing, and tissue cutting. Errors are typically detected in the immediate steps after the errors occurred, reinforcing the need for quality checks throughout the system.

Surgical pathology case reviews before sign-out: a College of American Pathologists Q-Probes study of 45 laboratories.

CONTEXT To avoid errors many surgical pathology services mandate review of a case by a second pathologist before reports are released (signed out). OBJECTIVE To study the extent and characteristics of such review. DESIGN Participants retrospectively examined up to 400 cases to identify a maximum of 30 cases reviewed by at least one additional pathologist before sign-out. For each case, participants documented the organ system, primary disease type, number of additional pathologists consulted, and the reason for case review. The main outcome measure was the fraction of surgical pathology cases that underwent second pathologist review before sign-out. RESULTS From 45 laboratories, examination of 18 032 surgical pathology cases yielded 1183 (6.6%) cases that had been reviewed before sign-out. The median laboratory reviewed 8.2% of cases. Three-fifths of reviews focused on 4 organ systems: gastrointestinal (20.5%), breast (16.0%), skin (12.7%), and female genital tract (10.0%). Malignant neoplasm far exceeded all other categories of disease in reviewed cases (45.3%). Cases were reviewed by one additional pathologist 78% of the time. Two dominant reasons for case review emerged: difficult diagnosis (46.2%) and audit required by departmental policy (43.0%). Most laboratories (71%) had departmental policies regarding review of cases. These laboratories reviewed cases about 33% more often than laboratories without policies (9.6% versus 6.5%). CONCLUSIONS Review of selected surgical pathology cases before sign-out is widely accepted with 71% of participant laboratories following policies to this effect. About 1 case in 15 (6.6%) were reviewed with the median laboratory of participants reviewing about 1 in 12 (8.2%).

Anatomic pathology databases and patient safety

CONTEXT The utility of anatomic pathology discrepancies has not been rigorously studied. OBJECTIVE To outline how databases may be used to study anatomic pathology patient safety. DESIGN The Agency for Healthcare Research and Quality funded the creation of a national anatomic pathology errors database to establish benchmarks for error frequency. The database is used to track more frequent errors and errors that result in more serious harm, in order to design quality improvement interventions intended to reduce these types of errors. In the first year of funding, 4 institutions (University of Pittsburgh, Henry Ford Hospital, University of Iowa, and Western Pennsylvania Hospital) reported cytologic-histologic correlation error data after standardizing correlation methods. Root cause analysis was performed to determine sources of error, and error reduction plans were implemented. PARTICIPANTS Four institutions self-reported anatomic pathology error data. MAIN OUTCOME MEASURES Frequency of cytologic-histologic correlation error, case type, cause of error (sampling or interpretation), and effect of error on patient outcome (ie, no harm, near miss, and harm). RESULTS The institutional gynecologic cytologic-histologic correlation error frequency ranged from 0.17% to 0.63%, using the denominator of all Papanicolaou tests. Based on the nongynecologic cytologic-histologic correlation data, the specimen sites with the highest discrepancy frequency (by project site) were lung (ranging from 16.5% to 62.3% of all errors) and urinary bladder (ranging from 4.4% to 25.0%). Most errors detected by the gynecologic cytologic-histologic correlation process were no-harm events (ranging from 10.7% to 43.2% by project site). Root cause analysis identified sources of error on both the clinical and pathology sides of the process, and error intervention programs are currently being implemented to improve patient safety. CONCLUSIONS A multi-institutional anatomic pathology error database may be used to benchmark practices and target specific high-frequency errors or errors with high clinical impact. These error reduction programs have national import.

Kaposiform Hemangioendothelioma of the Thymus

Kaposiform hemangioendothelioma is a rare pediatric neoplasm that presents most commonly in the soft tissues. We report the case of a 1-month-old infant who presented with stridor and was found to have a diffusely infiltrating tumor in the thymus that extended into the pericardium and up the carotid sheaths. Histologic examination revealed a vascular tumor infiltrating among the lobules of the lymphocyte-depleted thymus. The lesion had features of both a capillary hemangioma and Kaposi sarcoma. Immunoperoxidase studies on formalin-fixed, paraffin-embedded tissue demonstrated the neoplastic endothelial cells to be positive for vascular markers CD31 and CD34. Antibody to factor VIII-related antigen labeled feeding vessels, but failed to stain the lobules of tumor. Although these tumors have been treated in a fashion similar to capillary hemangiomas in the past, it may be important to differentiate Kaposiform hemangioendotheliomas because of their association with Kasabach-Merritt syndrome and recent success with more aggressive chemotherapy regimens.

Use of a new method in reaching consensus on the cause of cytologic-histologic correlation discrepancy

Pathologists exhibit very poor agreement in adjudicating the cause of cytologic-histologic correlation discrepancies, which contributes to problems in designing interventions to reduce discrepancy frequency. In this observational study, we developed a visual method of adjudicating discrepancy cause, termed the No-Blame Box method, which consisted of initially assessing specimen interpretability by separately evaluating specimen quality and the presence of tumor. Five pathologists blindly adjudicated the cause of discrepancy in pulmonary specimens from 40 patients. The kappa statistic of all pathologist pairs in adjudicating discrepancy cause using the No-Blame Box method ranged from 0.400 to 0.796, indicating acceptable to excellent agreement. Pathologists ranged in their assessment of specimen interpretability from 13% to 20%, and in no case did all 5 pathologists concur that a specimen was interpretable. Most discrepancies resulted from pathologists diagnosing noninterpretable samples. Pathologists who used the No-Blame Box showed significant agreement in the adjudication of discrepancy cause.

Frequency and outcome of cervical cancer prevention failures in the United States.

We measured the frequency and outcome of cervical cancer prevention failures that occurred in the Papanicolaou (Pap) and colposcopy testing phases involving 1,646,580 Pap tests in 4 American hospital systems between January 1, 1998, and December 31, 2004. We defined a screening failure as a 2-step or greater discordant Pap test result and follow-up biopsy diagnosis. A total of 5,278 failures were detected (0.321% of all Pap tests); 48% and 52% of failures occurred in the Pap test and colposcopy phases, respectively. Missed squamous cancers (1 in 187,786 Pap tests), glandular cancers (1 in 19,426 Pap tests), and high-grade lesions (1 in 6,870 Pap tests) constituted 4.1% of all failures. Unnecessary repeated tests or diagnostic delays occurred in 70.8% and 63.9% of failures involving high- and low-grade lesions, respectively. We conclude that cervical cancer prevention practices are remarkably successful in preventing squamous cancers, although a high frequency of failures results in low-impact negative outcomes.

Interpretive Diagnostic Error Reduction in Surgical Pathology and Cytology: Guideline From the College of American Pathologists Pathology and Laboratory Quality Center and the Association of Directors of Anatomic and Surgical Pathology

CONTEXT Additional reviews of diagnostic surgical and cytology cases have been shown to detect diagnostic discrepancies. OBJECTIVE To develop, through a systematic review of the literature, recommendations for the review of pathology cases to detect or prevent interpretive diagnostic errors. DESIGN The College of American Pathologists Pathology and Laboratory Quality Center in association with the Association of Directors of Anatomic and Surgical Pathology convened an expert panel to develop an evidence-based guideline to help define the role of case reviews in surgical pathology and cytology. A literature search was conducted to gather data on the review of cases in surgical pathology and cytology. RESULTS The panel drafted 5 recommendations, with strong agreement from open comment period participants ranging from 87% to 93%. The recommendations are: (1) anatomic pathologists should develop procedures for the review of selected pathology cases to detect disagreements and potential interpretive errors; (2) anatomic pathologists should perform case reviews in a timely manner to avoid having a negative impact on patient care; (3) anatomic pathologists should have documented case review procedures that are relevant to their practice setting; (4) anatomic pathologists should continuously monitor and document the results of case reviews; and (5) if pathology case reviews show poor agreement within a defined case type, anatomic pathologists should take steps to improve agreement. CONCLUSIONS Evidence exists that case reviews detect errors; therefore, the expert panel recommends that anatomic pathologists develop procedures for the review of pathology cases to detect disagreements and potential interpretive errors, in order to improve the quality of patient care.