Clinical impact and frequency of anatomic pathology errors in cancer diagnoses

Verification and classification bias interactions in diagnostic test accuracy studies for fine-needle aspiration biopsy

BACKGROUND

Reliable estimates of accuracy are important for any diagnostic test. Diagnostic accuracy studies are subject to unique sources of bias. Verification bias and classification bias are 2 sources of bias that commonly occur in diagnostic accuracy studies. Statistical methods are available to estimate the impact of these sources of bias when they occur alone. The impact of interactions when these types of bias occur together has not been investigated.

METHODS

We developed mathematical relationships to show the combined effect of verification bias and classification bias. A wide range of case scenarios were generated to assess the impact of bias components and interactions on total bias.

RESULTS

Interactions between verification bias and classification bias caused overestimation of sensitivity and underestimation of specificity. Interactions had more effect on sensitivity than specificity. Sensitivity was overestimated by at least 7% in approximately 6% of the tested scenarios. Specificity was underestimated by at least 7% in less than 0.1% of the scenarios.

CONCLUSIONS

Interactions between verification bias and classification bias create distortions in accuracy estimates that are greater than would be predicted from each source of bias acting independently.

Effect of substrate choice and tissue type on tissue preparation for spectral histopathology by Raman microspectroscopy

Raman spectroscopy is a non-destructive, non-invasive, rapid and economical technique which has the potential to be an excellent method for the diagnosis of cancer and understanding disease progression through retrospective studies of archived tissue samples. Historically, biobanks are generally comprised of formalin fixed paraffin preserved tissue and as a result these specimens are often used in spectroscopic research. Tissue in this state has to be dewaxed prior to Raman analysis to reduce paraffin contributions in the spectra. However, although the procedures are derived from histopathological clinical practice, the efficacy of the dewaxing procedures that are currently employed is questionable. Ineffective removal of paraffin results in corruption of the spectra and previous experiments have shown that the efficacy can depend on the dewaxing medium and processing time. The aim of this study was to investigate the influence of commonly used spectroscopic substrates (CaF2, Spectrosil quartz and low-E slides) and the influence of different histological tissue types (normal, cancerous and metastatic) on tissue preparation and to assess their use for spectral histopathology. Results show that CaF2 followed by Spectrosil contribute the least to the spectral background. However, both substrates retain paraffin after dewaxing. Low-E substrates, which exhibit the most intense spectral background, do not retain wax and resulting spectra are not affected by paraffin peaks. We also show a disparity in paraffin retention depending upon the histological identity of the tissue with abnormal tissue retaining more paraffin than normal.

The clinical significance of cytology versus histology-based diagnosis in small cell lung cancer: a retrospective study

OBJECTIVES

The aim of this study was to investigate the clinical significance of cytology versus histology-based diagnosis among patients diagnosed with small cell lung cancer (SCLC).

MATERIALS AND METHODS

Retrospective analysis of medical records of 443 patients with histologically or cytologically confirmed small cell lung carcinoma (SCLC) was performed. All patients received platinum-based chemotherapy regimens. Survival data (overall survival) were compared between patients with histology or cytology-based diagnosis in the overall study population as well as after stratification of patients according to disease stage (limited or extensive) at the time of diagnosis.

RESULTS

Distribution of demographics and clinicopathological characteristics among the two groups ("histology" and "cytology") was similar. No statistically significant differences in the survival curves between the "histology" and "cytology" groups were found in the overall study population (log rank test, p=0.237), as well as in the subgroup of patients with limited disease (log rank test, p=0.474). In contrast, patients with histology-based diagnosis had a statistically significant longer survival as compared to those with cytology-based diagnosis in the extensive disease subgroup (log rank test, p=0.031), but this association was not retained after adjusting the analysis for demographics and clinical characteristics via a Cox regression model (HR=1.18, 95% CI: 0.96-1.44, p=0.110).

CONCLUSION

The results of our study suggest that the type of diagnostic modality employed (histology or cytology-based) for the establishment of a diagnosis of SCLC may not have a significant effect on the overall survival of patients. Further studies are warranted to further investigate this important, yet rather unexplored, issue.

Patient-initiated second opinions: systematic review of characteristics and impact on diagnosis, treatment, and satisfaction

The impact of second opinions on diagnosis in radiology and pathology is well documented; however, the value of patient-initiated second opinions for diagnosis and treatment in general medical practice is unknown. We conducted a systematic review of patient-initiated second opinions to assess their impact on clinical outcomes and patient satisfaction and to determine characteristics and motivating factors of patients who seek a second opinion. We searched PubMed, EMBASE, Cochrane, and Academic OneFile databases using Medical Subject Headings (MeSH) indexes and keyword searches. Search terms included referral and consultation, patient-initiated, patient preference, patient participation, second opinion, second review, and diagnosis. Multiple reviewers screened abstracts and articles to determine eligibility and extract data. We assessed risk of bias using the Cochrane Risk of Bias Tool and rated study quality using Cochrane's GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. We screened 1342 abstracts and reviewed full text of 41 articles, identifying 7 articles that reported clinical agreement data and 10 that discussed patient characteristics, motivation, and satisfaction. We found that a second opinion typically confirms the original diagnosis or treatment regimen but that 90% of patients with poorly defined conditions remain undiagnosed. However, 10% to 62% of second opinions yield a major change in the diagnosis, treatment, or prognosis. A larger fraction of patients receive different advice on treatment than on diagnosis. Factors motivating a second opinion include diagnosis or treatment confirmation, dissatisfaction with a consultation, desire for more information, persistent symptoms, or treatment complications. Patients generally believed that second opinions were valuable. Second opinions can result in diagnostic and treatment differences. The literature on patient-initiated second opinions is limited, and the accuracy of the second opinion through follow-up is generally unknown. Standardized methods and outcome measures are needed to determine the value of second opinions, and the potential of second opinions to reduce diagnostic errors merits more rigorous evaluation.

Whole slide imaging diagnostic concordance with light microscopy for breast needle biopsies

This study investigated the diagnostic accuracy of whole slide imaging (WSI) in breast needle biopsy diagnosis in comparison with standard light microscopy (LM). The study examined the effects of image capture magnification and computer monitor quality on diagnostic concordance of WSI and LM. Four pathologists rendered diagnoses using WSI to examine 85 breast biopsies (92 parts; 786 slides) consisting of benign and malignant cases. Each WSI case was evaluated using images captured at either ×20 or ×40 magnifications and viewed using a Digital Imaging and Communication in Medicine (DICOM) grade, color-calibrated monitor or a standard, desktop liquid-crystal display (LCD) monitor. For each combination, the WSI result was compared with the original, LM diagnosis. The overall concordance rate observed between WSI and LM was 97.1% (95% confidence intervals [CI]: 94.3%-98.5%). After a washout period, all cases were reviewed a second time by each pathologist after using LM, and the second LM diagnosis was compared with the WSI diagnosis rendered by the same pathologist. Intraobserver concordance between WSI and LM was 95.4% (95% CI: 92.2%-97.4%). The second LM diagnoses were also compared with the original LM diagnoses, and the observed interobserver LM concordance rate was 97.3% (95% CI: 93.1%-99.0%). The study data demonstrated that breast needle biopsy diagnoses rendered by WSI were equivalent to diagnoses rendered by LM. No diagnostic differences were detected between the underlying viewing system parameters of monitor quality and image capture resolution. The results of this study demonstrated that WSI can be effectively used in subspecialty diagnostic cases where a minimum amount of tissue is available.

Evaluation of computer-aided detection and diagnosis systems

Computer-aided detection and diagnosis (CAD) systems are increasingly being used as an aid by clinicians for detection and interpretation of diseases. Computer-aided detection systems mark regions of an image that may reveal specific abnormalities and are used to alert clinicians to these regions during image interpretation. Computer-aided diagnosis systems provide an assessment of a disease using image-based information alone or in combination with other relevant diagnostic data and are used by clinicians as a decision support in developing their diagnoses. While CAD systems are commercially available, standardized approaches for evaluating and reporting their performance have not yet been fully formalized in the literature or in a standardization effort. This deficiency has led to difficulty in the comparison of CAD devices and in understanding how the reported performance might translate into clinical practice. To address these important issues, the American Association of Physicists in Medicine (AAPM) formed the Computer Aided Detection in Diagnostic Imaging Subcommittee (CADSC), in part, to develop recommendations on approaches for assessing CAD system performance. The purpose of this paper is to convey the opinions of the AAPM CADSC members and to stimulate the development of consensus approaches and "best practices" for evaluating CAD systems. Both the assessment of a standalone CAD system and the evaluation of the impact of CAD on end-users are discussed. It is hoped that awareness of these important evaluation elements and the CADSC recommendations will lead to further development of structured guidelines for CAD performance assessment. Proper assessment of CAD system performance is expected to increase the understanding of a CAD system's effectiveness and limitations, which is expected to stimulate further research and development efforts on CAD technologies, reduce problems due to improper use, and eventually improve the utility and efficacy of CAD in clinical practice.

The current and ideal state of anatomic pathology patient safety

An anatomic pathology diagnostic error may be secondary to a number of active and latent technical and/or cognitive components, which may occur anywhere along the total testing process in clinical and/or laboratory domains. For the pathologist interpretive steps of diagnosis, we examine Kahneman's framework of slow and fast thinking to explain different causes of error in precision (agreement) and in accuracy (truth). The pathologist cognitive diagnostic process involves image pattern recognition and a slow thinking error may be caused by the application of different rationally-constructed mental maps of image criteria/patterns by different pathologists. This type of error is partly related to a system failure in standardizing the application of these maps. A fast thinking error involves the flawed leap from image pattern to incorrect diagnosis. In the ideal state, anatomic pathology systems would target these cognitive error causes as well as the technical latent factors that lead to error.

Evaluating the Connections Between Primary Care Practice and Clinical Laboratory Testing: A Review of the Literature and Call for Laboratory Involvement in the Solutions

Context.—Growing evidence has demonstrated a high frequency of quality gaps in laboratory medicine, with recent studies estimating that 15% to 54% of primary care medical errors reported by primary care physicians and staff are related to the testing process. However, there is lack of evidence-based performance metrics in the preanalytic and postanalytic phases of the testing pathway for primary care practices.

Objective.—To use results of the literature review to assist in the development of quality indicators that could improve preanalytic and postanalytic processes in primary care–based laboratory medicine.

Data Sources.—Literature in Ovid/MEDLINE from 2001 through 2011 was searched as a primary source of information. Ninety-five peer-reviewed and non–peer-reviewed publications were retrieved following title and abstract review and 10 articles were reviewed in their entirety by the authors. A systematic review of the literature was conducted regarding the connections between clinical laboratories and primary care offices and the resulting errors. Root causes of errors were categorized into 7 major themes: process failures, delays, communication gaps, errors in judgment and cognition, influence of minorities/language, practice culture, and lack of patient centeredness. Selected articles were evaluated for evidence quality using the Systematic Evidence Review and Evaluation Methods for Quality Improvement grading scale developed by the Centers for Disease Control and Prevention.

Conclusions.—The focused literature review documented 7 key error themes in the laboratory medicine/primary care testing process. Performance metrics related to these themes are proposed that deserve future study for evidence-based improvement.

Development of a decision-analytic model for the application of STR-based provenance testing of transrectal prostate biopsy specimens

BACKGROUND

The diagnostic algorithm for most cancers includes the assessment of a tissue specimen by a surgical pathologist, but if specimen provenance is uncertain, the diagnostic and therapeutic process carries significant risk to the patient. Over the last decade, short tandem repeat (STR) analysis has emerged as a DNA-based method with clinical applicability for specimen identity testing (also known as specimen provenance testing). Although the clinical utility of identity testing using STR-based analysis has been demonstrated in many studies, its economic value has not been established.

METHODS

We developed a decision-analytic model of the application of STR-based provenance testing of transrectal prostate biopsy specimens obtained as part of routine clinical care to rule out the presence of adenocarcinoma of the prostate, as compared with no STR-based testing. Using parameter values drawn from the published literature, the cost-effectiveness of STR-based testing was quantified by calculating the incremental cost-effectiveness ratio per quality-adjusted life-year gained.

RESULTS

In comparison to the current standard practice of no identity testing, identity testing by STR-based analysis has an incremental cost-effectiveness ratio of $65,570 per quality-adjusted life-year gained at a testing cost of $618 per person. At a cost of $515 per person, identity testing would meet the conservative standard of $50,000 per quality-adjusted life-year. At a test cost of $290 per person, identity testing would be cost saving.

CONCLUSION

Given the rapidly declining pricing of STR-based identity testing, it is likely that testing to confirm the identity of positive prostate biopsy samples will be a cost-effective method for preventing treatment errors stemming from misidentification. Studies to formally establish the frequency of specimen provenance errors in routine clinical practice would therefore seem justified.

Directed peer review in surgical pathology

Second pathologist peer review is used in many surgical laboratory quality-assurance programs to detect error. Directed peer review is 1 method of second review and involves the selection of specific case types, such as cases from a particular site of anatomic origin. The benefits of using the directed peer review method are unique and directed peer review detects both errors in diagnostic accuracy and precision and this detection may be used to improve practice. We utilize the Lean quality improvement A3 method of problem solving to investigate these issues. The A3 method defines surgical pathology diagnostic error and describes the current state in surgical pathology, performs root cause analysis, hypothesizes an ideal state, and provides opportunities for improvement in error reduction. Published data indicate that directed peer review practices may be used to prevent active cognitive errors that lead to patient harm. Pathologists also may use directed peer review data to target latent factors that contribute to error and improve diagnostic precision.

Improving the histopathologic diagnosis of pediatric malignancies in a low-resource setting by combining focused training and telepathology strategies

BACKGROUND

Accurate diagnosis is critical for optimal management of pediatric cancer. Pathologists with experience in pediatric oncology are in short supply in the developing world. Telepathology is increasingly used for consultations but its overall contribution to diagnostic accuracy is unknown.

PROCEDURE

We developed a strategy to provide a focused training in pediatric cancer and telepathology support to pathologists in the developing world. After the training period, we compared trainee's diagnoses with those of an experienced pathologist. We next compared the effectiveness of static versus dynamic telepathology review in 127 cases. Results were compared by Fisher's exact test.

RESULTS

The diagnoses of the trainee and the expert pathologist differed in only 6.5% of cases (95% CI, 1.2-20.0%). The overall concordance between the telepathology and original diagnoses was 90.6% (115/127; 95% CI, 84.1-94.6%).

CONCLUSIONS

Brief, focused training in pediatric cancer histopathology can improve diagnostic accuracy. Dynamic and static telepathology analyses are equally effective for diagnostic review.

Multisite validation study to determine performance characteristics of a 92-gene molecular cancer classifier

PURPOSE

Accurate tumor classification is essential for cancer management as patient outcomes improve with use of site- and subtype-specific therapies. Current clinicopathologic evaluation is varied in approach, yet standardized diagnoses are critical for determining therapy. While gene expression-based cancer classifiers may potentially meet this need, imperative to determining their application to patient care is validation in rigorously designed studies. Here, we examined the performance of a 92-gene molecular classifier in a large multi-institution cohort.

EXPERIMENTAL DESIGN

Case selection incorporated specimens from more than 50 subtypes, including a range of tumor grades, metastatic and primary tumors, and limited tissue samples. Formalin-fixed, paraffin-embedded tumors passed pathologist-adjudicated review between three institutions. Tumor classification using a 92-gene quantitative reverse transcriptase polymerase chain reaction (RT-PCR) assay was conducted on blinded tumor sections from 790 cases and compared with adjudicated diagnoses.

RESULTS

The 92-gene assay showed overall sensitivities of 87% for tumor type [95% confidence interval (CI), 84-89] and 82% for subtype (95% CI, 79-85). Analyses of metastatic tumors, high-grade tumors, or cases with limited tissue showed no decrease in comparative performance (P = 0.16, 0.58, and 0.16). High specificity (96%-100%) was showed for ruling in a primary tumor in organs commonly harboring metastases. The assay incorrectly excluded the adjudicated diagnosis in 5% of cases.

CONCLUSIONS

The 92-gene assay showed strong performance for accurate molecular classification of a diverse set of tumor histologies. Results support potential use of the assay as a standardized molecular adjunct to routine clinicopathologic evaluation for tumor classification and primary site diagnosis.

Concordance between whole-slide imaging and light microscopy for routine surgical pathology

The use of high-resolution digital images of histopathology slides as a routine diagnostic tool for surgical pathology was investigated. The study purpose was to determine the diagnostic concordance between pathologic interpretations using whole-slide imaging and standard light microscopy. Two hundred fifty-one consecutive surgical pathology cases (312 parts, 1085 slides) from a single pathology service were included in the study after cases had been signed out and reports generated. A broad array of diagnostic challenges and tissue sources were represented, including 52 neoplastic cases. All cases were digitized at ×20 and presented to 2 pathologists for diagnosis using whole-slide imaging as the sole diagnostic tool. Diagnoses rendered by the whole-slide imaging pathologists were compared with the original light microscopy diagnoses. Overall concordance between whole-slide imaging and light microscopy as determined by a third pathologist and jury panel was 96.5% (95% confidence interval, 94.8%-98.3%). Concordance between whole-slide imaging pathologists was 97.7% (95% confidence interval, 94.7%-99.2%). Five cases were discordant between the whole-slide imaging diagnosis and the original light microscopy diagnosis, of which 2 were clinically significant. Discordance resulted from interpretive criteria or diagnostic error. The whole-slide imaging modality did not contribute to diagnostic differences. Problems encountered by the whole-slide imaging pathologists primarily involved the inability to clearly visualize nuclear detail or microscopic organisms. Technical difficulties associated with image scanning required at least 1 slide be rescanned in 13% of the cases. Technical and operational issues associated with whole-slide imaging scanning devices used in this study were found to be the most significant obstacle to the use of whole-slide imaging in general surgical pathology.

Intersection of biobanking and clinical care: should discrepant diagnoses and pathological findings be returned to research participants?

Diagnostic discrepancies occur when the diagnosis made on a biospecimen during the course of review at a biobank differs from the original clinical diagnosis. These diagnostic discrepancies detected during biobanking present unique challenges that are distinct from other types of research results or incidental findings. The proposed process for reporting diagnostic discrepancies or pathological incidental findings identified through a quality assurance evaluation at the biobank includes verification of the biospecimen identity, verification of the diagnosis within the biobank, and re-review of the case by the pathologist at the biospecimen collection site. If the pathologist at the biobank and the original pathologist do not reach agreement, an impartial and knowledgeable third party is consulted. The decision as to whether and how to notify research participants of any confirmed changes in diagnosis would be determined by institutional procedures. Implementation of this proposed process will require clear delineation of the roles and responsibilities of all involved parties in order to promote excellence in patient care and ensure that researchers have access to biospecimens of requisite quality.Genet Med 2012:14(4):417-423.

Effectiveness of rapid prescreening and 10% rescreening in liquid-based Papanicolaou testing

Although rapid prescreening (RPS) has been shown to be an effective quality control procedure for detecting false-negative conventional Papanicolaou (Pap) tests, RPS has not been widely implemented in the United States. In our laboratory, cytotechnologists performed RPS in 3,567 liquid-based Pap tests: 1,911 SurePath (BD Diagnostics-TriPath, Burlington, NC) preparations that were manually screened and 1,656 ThinPrep Pap tests (Hologic, Bedford, MA) that were imaged using the ThinPrep Imaging System (Hologic). We compared the sensitivity of RPS, 10% rescreening (R-10%), and routine screening (RS). In contrast with previously published findings, we found that RS + RPS did not improve screening sensitivity compared with RS + R-10%. These results support the following hypotheses: (1) Higher baseline RS sensitivity as a result of Pap test diagnoses standardization implemented for quality improvement purposes decreases the performance impact of RPS. (2) R-10% and RPS quality assurance methods detect diagnostic failures caused by different types of cognitive errors.

High-throughput profiling of tissue and tissue model microarrays: Combined transmitted light and 3-color fluorescence digital pathology

For many years pathologists have used Hematoxylin and Eosin (H&E), single marker immunohistochemistry (IHC) and in situ hybridization with manual analysis by microscopy or at best simple digital imaging. There is a growing trend to update pathology to a digital workflow to improve objectivity and productivity, as has been done in radiology. There is also a need for tissue-based multivariate biomarker assays to improve the accuracy of diagnostic, prognostic, and predictive testing. Multivariate tests are not compatible with the traditional single marker, manual analysis pathology methods but instead require a digital platform with brightfield and fluorescence imaging, quantitative image analysis, and informatics. Here we describe the use of the Hamamatsu NanoZoomer Digital Pathology slide scanner with HCImage software for combined brightfield and multiplexed fluorescence biomarker analysis and highlight its applications in biomarker research and pathology testing. This combined approach will be an important aid to pathologists in making critical diagnoses.

Assessment of Latent Factors Contributing to Error: Addressing Surgical Pathology Error Wisely

Context.—Methods to improve surgical pathology patient safety include measuring the frequency of error in specific steps of the surgical pathology testing process, root cause analysis of active and latent components, and implementation of quality improvement initiatives.

Objective.—To determine the frequency and cause of near-miss events in the specimen accessioning, setup, and biopsy-only gross examination testing steps of anatomic pathology.

Design.—We used an observational checklist method to identify near-miss events. We performed root cause analysis to determine latent factors contributing to near-miss events. We conducted observations for 45 hours during 5 days, involving the accessioning and processing of 335 specimens.

Results.—We detected a total of 2310 process-dependent and 266 operator-dependent near-miss events, resulting in a near-miss–event frequency of 5.5 per specimen. Root cause analysis showed that all process and operator near-miss events were associated with multiple system latent factors, including lack of standardized protocols, appropriate knowledge transfer, and focus on safety culture.

Conclusion.—We conclude that the increased focus on surgical pathology near-miss events will reveal latent factors that may be targeted for improvement.

Study of amended reports to evaluate and improve surgical pathology processes

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).

Characteristics and predictors of missed opportunities in lung cancer diagnosis: an electronic health record-based study

PURPOSE

Understanding delays in cancer diagnosis requires detailed information about timely recognition and follow-up of signs and symptoms. This information has been difficult to ascertain from paper-based records. We used an integrated electronic health record (EHR) to identify characteristics and predictors of missed opportunities for earlier diagnosis of lung cancer.

METHODS

Using a retrospective cohort design, we evaluated 587 patients of primary lung cancer at two tertiary care facilities. Two physicians independently reviewed each case, and disagreements were resolved by consensus. Type I missed opportunities were defined as failure to recognize predefined clinical clues (ie, no documented follow-up) within 7 days. Type II missed opportunities were defined as failure to complete a requested follow-up action within 30 days.

RESULTS

Reviewers identified missed opportunities in 222 (37.8%) of 587 patients. Median time to diagnosis in cases with and without missed opportunities was 132 days and 19 days, respectively (P < .001). Abnormal chest x-ray was the clue most frequently associated with type I missed opportunities (62%). Follow-up on abnormal chest x-ray (odds ratio [OR], 2.07; 95% CI, 1.04 to 4.13) and completion of first needle biopsy (OR, 3.02; 95% CI, 1.76 to 5.18) were associated with type II missed opportunities. Patient adherence contributed to 44% of patients with missed opportunities.

CONCLUSION

Preventable delays in lung cancer diagnosis arose mostly from failure to recognize documented abnormal imaging results and failure to complete key diagnostic procedures in a timely manner. Potential solutions include EHR-based strategies to improve recognition of abnormal imaging and track patients with suspected cancers.

Limiting the Use of Atypical/Inconclusive as a Category in Nongynecologic Cytology Specimens

Context.—Atypical has served as a descriptive term in cytology since the birth of the specialty by Dr Papanicolaou. This indeterminate diagnosis often results in repeat biopsies or additional tissue sampling and a needless delay in patient care if used inappropriately. Because of the definitional ambiguity of this term and the associated physician frustration, we have made a concerted effort at Methodist Hospital since 1995 to minimize the use of atypical as a diagnostic category.

Objective.—To evaluate whether the dissolution of the atypical category has increased our cytologic-histologic discordance rate to more than the published reference range.

Design.—From March 3, 2006, through December 31, 2008, all nongynecologic cases with atypical/indeterminate listed as the general diagnostic category were identified and retrieved from our laboratory data files. We then assessed the cytologic-histologic correlation rate during the corresponding time frame.

Results.—A total of 48 atypical cases (0.2%) from 19 347 nongynecologic specimens were identified. Of the atypical cases, 52% (25 of 48) had intradepartmental consultation, 58% (28 of 48) had additional preparations examined, and 29% (14 of 48) documented limitations because of poor preservation. Our cytologic-histologic discrepancy rate for the period was 5.5% (214 of 3912 cases), with 89.3% (191 of 214 cases) resulting from sampling issues. On review of the small percentage of cytologic interpretative discrepancies, only one case was unhampered by less than 10% tumor cellularity or poor preservation.

Conclusions.—Not using atypical as a diagnostic category, unless defined by Bethesda guidelines, has not affected our cytologic-histologic correlation rate.

Dermatological patient safety: problems and solutions

BACKGROUND

Patient safety issues are the forefront of delivering effective quality healthcare. The fast pace and high volume of dermatology practice presents an opportunity for new research on error prevention and patient safety.

OBJECTIVE

To identify areas of concern in patient safety to introduce starting points for new improvement projects in dermatology.

METHODS

Aliterature search was performed using the PubMed database with the search terms 'patient safety' and 'quality of care'. The articles were categorized into three topics concerning patient safety research: safety in treatment and procedures received; safety issues related to facility infrastructure; and human resource management.

RESULTS

Many issues identified as healthcare shortcomings such as wrong site surgery, patient misidentification, specimen errors, medication errors, communication failure, poor teamwork, healthcare worker management defects, and facility safety design problems were discussed in the literature. Each of these requires exploration with new safety initiatives for resolution. Alimitation included omitting pieces on occupational health and safety that could contribute to overall patient safety. Our search also included only data from one database.

CONCLUSIONS

Patient safety is an ever-evolving process requiring continuous attention by practicing physicians including dermatologists, healthcare staff, patients, and research scholars to discover and implement new safety initiatives for overall healthcare improvement.

An active pixel sensor x-ray diffraction (APXRD) system for breast cancer diagnosis

This paper describes the potential application of an active pixel sensor-based x-ray diffraction (APXRD) system in the field of breast cancer diagnosis. The design and initial testing of the system was reported previously (Bohndiek et al 2008b Phys. Med. Biol. 53 655-72). The system has potential both as a 'diffraction enhanced breast imager' (DEBI) and as a probe for quantitative analysis of breast biopsy samples. The resolution of the system in a DEBI arrangement is 1 mm and the contrast available using a material-specific x-ray diffraction image was found to be up to seven times greater than that of a transmission image. Scatter signatures from a series of biopsy-equivalent samples, ranging in composition from 100% fat to 100% fibrous tissue, were acquired with the APXRD system. Multivariate data analysis was used to produce a partial least squares (PLS) model sensitive to sample fat content. The final model is able to accurately predict the fat content of a series of unknown samples and is robust to significant added noise. This suggests that the APXRD system could provide a simple, semi-automated, quantitative measurement system for analysis of breast biopsy samples. Training on a range of scatter signatures from real breast biopsy samples covering various stages of disease is now needed to test this hypothesis.

[Impact of pathological review by an expert on the diagnosis and management of patients with cancer in Aquitania]

AIMS

The goal of this work was to evaluate the impact of expert pathological second opinion on the diagnosis and management of patients with cancer, in a French region (Aquitaine) and with an economic point of view.

MATERIAL AND METHODS

The study was first quantitative, performed retrospectively on all cases of cancer, voluntary sent for a second opinion to an expert pathologist of two centers. Secondly, we restricted the study to lymphoid, melanocytic and soft tissue tumors sent for second opinion. We considered that the expert review had an important diagnostic impact either when the initial pathologist sent the specimen to identify or classify malignant tumor or hesitated between benign and malignant tumor or had no hypothesis, or if there were discordant diagnoses (malignant/benign) between the two pathologists. We considered that the expert review had a high therapeutic impact if the disagreement between initial and expert diagnoses induced a complete modification in therapy. We evaluated the cost of second opinion for the expert centers and the cost of care management.

RESULTS

Over the year 2006, the expert centers received 5077 lesions for consultation: 3769 specimens were sent by a pathologist for a second review, 1324 by pathologists of Aquitania and of these, 751 samples were submitted for lymphoid (55%), soft tissues (30%) or melanocytic tumors (15%). There was an important diagnostic impact for 75% of the samples; the impact of the expert review on patient management was considered high for 46% of specimens and the expert pathological diagnosis modified the clinical prognosis for 40% of the specimens. We estimated that for 53 discordant diagnoses (malignant/benign), second opinion allowed an economy of 500,000 euro.

CONCLUSION

Expert second opinion is very important not only for diagnosis and management for patient with cancer but also for economic reasons.

Measuring quality in anatomic pathology

This article focuses mainly on diagnostic accuracy in measuring quality in anatomic pathology, noting that measuring any quality metric is complex and demanding. The authors discuss standardization and its variability within and across areas of care delivery and efforts involving defining and measuring error to achieve pathology quality and patient safety. They propose that data linking error to patient outcome are critical for developing quality improvement initiatives targeting errors that cause patient harm in addition to using methods of root cause analysis, beyond those traditionally used in cytologic-histologic correlation, to assist in the development of error reduction and quality improvement plans.

Opportunities to improve quality in laboratory medicine

Modern laboratories offer cost-effective and precise analysis of specimens. Unfortunately, accurate laboratory tests still can result in bad outcomes because of errors in the pre- and postanalytic phases of testing. Important sources of error in the preanalytic phase include errors in test ordering, patient identification, specimen collection, transport, and accessioning. Errors in the postanalytic phase often relate to turn-around time, delivery of reports, or interpretation of results. This article focuses on the key opportunities for improvement in quality.

Misinterpretation of histopathological results as an important risk factor for unneeded surgery - case report of a "near miss" event in a pregnant woman

The oral cavity may exhibit a vast number of pathologic conditions, often dealt with by different medical disciplines. Combined with a substantial variation in clinical appearance, an accurate diagnosis may provide difficult to establish in selected cases. Histopathological investigations are therefore mandatory for correct diagnosis and adequate treatment. We describe a common, truly benign condition in the oral cavity, which due to histopathological misinterpretation was planned for major surgery and subsequent chemotherapy. This was avoided by spontaneous regression of the lesion. The case illustrates that uncritical trust in laboratory diagnostic tests may lead to severe mistreatment.

Overconfidence as a cause of diagnostic error in medicine

The great majority of medical diagnoses are made using automatic, efficient cognitive processes, and these diagnoses are correct most of the time. This analytic review concerns the exceptions: the times when these cognitive processes fail and the final diagnosis is missed or wrong. We argue that physicians in general underappreciate the likelihood that their diagnoses are wrong and that this tendency to overconfidence is related to both intrinsic and systemically reinforced factors. We present a comprehensive review of the available literature and current thinking related to these issues. The review covers the incidence and impact of diagnostic error, data on physician overconfidence as a contributing cause of errors, strategies to improve the accuracy of diagnostic decision making, and recommendations for future research.

The effect of continuous monitoring of cytologic-histologic correlation data on cervical cancer screening performance

CONTEXT

The use of Papanicolaou (Pap) test cytologic-histologic correlation in quality improvement activities is not well studied.

OBJECTIVE

To determine if continuous monitoring of correlation data improves performance.

DESIGN

Participants in the College of American Pathologists Q-Tracks program (213 laboratories) self-reported the number of Pap test-histologic biopsy correlation discrepancies every quarter for up to 8 years. A mixed linear model determined if the length of participation in the Q-Tracks program was associated with improved performance. Main outcome measures were predictive value of a positive Pap test, Pap test sensitivity, sampling sensitivity, and proportion of positive histologic diagnoses following a Pap test diagnosis of atypical squamous cells or atypical glandular cells.

RESULTS

Institutions evaluated 287,570 paired Pap test-histologic correlation specimens and found 98,424 (34.2%) true-positive Pap test correlations, 19,006 (6.6%) false-positive Pap test correlations, and 6575 (2.3%) false-negative Pap test correlations. The mean predictive value of a positive Pap test, sensitivity, screening and interpretive sensitivity, sampling sensitivity, and proportion of positive histologic diagnoses following a Pap test diagnosis of atypical squamous or glandular cells were 83.6%, 93.7%, 99.2%, 94.2%, 60.3%, and 38.8%, respectively. Longer participation was significantly associated with a higher predictive value of a positive Pap test (P = .01), higher Pap test sensitivity (P = .002), higher Pap test sampling sensitivity (P = .03), and higher proportion of positive histologic diagnoses for a Pap test diagnosis of atypical squamous cells (P < .001).

CONCLUSIONS

Long-term monitoring of cytologic-histologic correlation is associated with improvement in cytologic-histologic correlation performance.

Errors in cancer diagnosis: current understanding and future directions

PURPOSE

Errors in cancer diagnosis are likely the most harmful and expensive types of diagnostic errors. We reviewed the literature to understand the prevalence, origins, and prevention of errors in cancer diagnosis, focusing on common cancers for which early diagnosis offers clear benefit (melanoma and cancers of the breast, colon, and lung).

METHODS

We searched the Cochrane Library and PubMed from 1966 until April 2007 for publications that met our review criteria and manually searched references of key publications. Our search yielded 110 studies, of which nine were prospective studies and the remaining were retrospective studies.

RESULTS

Errors in cancer diagnosis were not uncommon in autopsy studies and were associated with significant harm and expense in malpractice claims. Literature on prevalence was scant. For each type of cancer, we classified preventable errors according to their origins in patient-physician encounters in the clinic setting, diagnostic test or procedure performance, pathologic confirmation of diagnosis, follow-up of patient or test result, or patient-related delays.

CONCLUSION

The literature reflects advanced knowledge of contributory factors and prevention for diagnostic errors related to the performance of procedures and imaging tests and emerging understanding of pathology errors. However, prospective studies are few, as are studies of diagnostic errors arising from the clinical encounter and patient follow-up. Future research should examine further the system and cognitive problems that lead to the many contributory factors we identified, and address interdisciplinary interventions to prevent errors in cancer diagnosis.

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.

Why current breast pathology practices must be evaluated. A Susan G. Komen for the Cure white paper: June 2006

Ending breast cancer has long been the mission of Susan G. Komen for the Cure. To this end, the organization has a strong interest and proven track record in ensuring public investment in quality breast health and breast cancer care. Recently, Susan G. Komen for the Cure identified major issues in the practice of pathology that have a negative impact on the lives of thousands of breast cancer patients in the United States. These issues were identified through a comprehensive literature review and interviews conducted in 2005-2006 with experts in oncology, breast pathology, surgery, and radiology. The interviewees practiced in community, academic, and cooperative group settings. Komen for the Cure has identified four areas that have a direct impact on the quality of care breast cancer patients receive in the United States, the accuracy of breast pathology diagnostics, the effects of current health insurance, and reimbursement policies on patients who are evaluated for a possible breast cancer diagnosis, the substantial decrease in tissue banking participation, particularly during a time of rapid advances in biologically correlated clinical science and the role for the Susan G. Komen for the Cure, pathology professional societies and the Federal government in ensuring that breast pathology practices meet the highest possible standards in the United States Concerns surrounding the quality and practice of breast pathology are not limited to diagnostic accuracy. Other considerations include, training and proficiency of pathologists who are evaluating breast specimens, the lack of integration of pathologists in the clinical care team, inadequate compensation for the amount of work required to thoroughly analyze specimens, potential loss in translational research as a result of medical privacy regulations, and the lack of mandatory uniform pathology practice standards without any way to measure the degree of variation or to remedy it.

Effect of Lean method implementation in the histopathology section of an anatomical pathology laboratory

Background:

In the USA, the lack of processes standardisation in histopathology laboratories leads to less than optimal quality, errors, inefficiency and increased costs. The effectiveness of large-scale quality improvement initiatives has been evaluated rarely.

Aim:

To measure the effect of implementation of a Lean quality improvement process on the efficiency and quality of a histopathology laboratory section.

Methods:

A non-concurrent interventional cohort study from 1 January 2003 to 31 December 2006 was performed, and the Lean process was implemented on 1 January 2004. Also compared was the productivity of the Lean histopathology section to a sister histopathology section that did not implement Lean processes. Pre- and post-Lean specimen turnaround time and productivity ratios (work units/full time equivalents) were measured. For 200 Lean interventions, a 5-part Likert scale was used to assess the impact on error, success and complexity.

Results:

In the Lean laboratory, the mean monthly productivity ratio increased from 3439 to 4074 work units/full time equivalents (p<0.001) as the mean daily histopathology section specimen turnaround time decreased from 9.7 to 9.0 h (p = 0.01). The Lean histopathology section had a higher productivity ratio compared with a sister histopathology section (1598 work units/full time equivalents, p<0.001) that did not implement Lean processes. The mean impact, success and complexity of interventions were 2.4, 2.7 and 2.5, respectively. The mean number of specific error causes affected by individual interventions was 2.6.

Conclusion:

It is concluded that Lean process implementation improved efficiency and quality in the histopathology section.

Urine cytology discrepancies: frequency, causes, and outcomes

Although urine cytology is used for the early detection and surveillance of urothelial carcinoma, there has been little study of the frequency, causes, and outcomes of cytologic-histologic discrepancies. We obtained histologic follow-up in 361 (6.2%) of 5,785 voided, 124 (19.5%) of 636 lower tract instrumented, and 23 (33%) of 69 upper tract urinary cytologic specimens from 1 institution during a 2-year timeframe to determine diagnostic discrepancy frequency and outcomes. Cytologic-histologic discrepancies were observed in 208 (40.9%) cases with histologic followup, and the cause of discrepancy was interpretation and sampling in 35.1% and 63.0%, respectively. Of all discrepancies, 101 (48.6%) resulted in minimal or mild harm, consisting mainly of repeated testing and/or diagnostic delays. Severe harm never was observed. We conclude that current screening and surveillance methods that incorporate urine cytology are accurate in diagnosing urothelial cancer. However, the current protocols result in potentially reducible errors that lead to unnecessary testing and diagnostic delays.

Medicolegal liability in surgical pathology: a consideration of underlying causes and selected pertinent concepts

Malpractice actions against surgical pathologists are still relatively uncommon, but they have increased in frequency over time and are associated with sizable indemnity figures. This discussion categorizes areas of liability in surgical pathology into three groups: those that represent health system flaws (problems with specimen identification, or transportation, or both; lack of clinical information or erroneous information; sampling effects and defects; and poorly reproducible or poorly defined diagnostic or prognostic criteria), others that exist at the interface between the system and individuals (allowing clinicians to bypass pathologic review of referred specimens; acceding to clinical demands for inadvisable procedures; and working in a disruptive environment), and truly individual errors by pathologists (lapses in reasoning; deficiencies concerning continuity in the laboratory; invalid assumptions regarding recipients of surgical pathology reports; over-reliance on the results of "special" tests; and problems with peer consultation). Finally, two important topic areas are discussed that commonly enter into lawsuits filed against surgical pathologists; namely, "delay in diagnosis" of malignant neoplasms and "failure to provide adequate prognostic information." Based on a review of the pertinent literature, we conclude that the clinical courses of most common malignancies are not affected in a significant manner by delays in diagnosis. Moreover, the practice of using "personalized external validity" for supposedly prognostic tests is examined, with the resulting opinion that prognostication of tumor behavior in individual patients is not reliable using anything but anatomic staging systems.

Original research in pathology: judgment, or evidence-based medicine?

Pathology is both a medical specialty and an investigative scientific discipline, concerned with understanding the essential nature of human disease. Ultimately, pathology is accountable as well, as measured by the accuracy of our diagnoses and the resultant patient care outcomes. As such, we must consider the evidence base underlying our practices. Within the realm of Laboratory Medicine, extensive attention has been given to testing accuracy and precision. Critical examination of the evidence base supporting the clinical use of specific laboratory tests or technologies is a separate endeavor, to which specific attention must be given. In the case of anatomic pathology and more specifically surgical pathology, the expertise required to render a diagnosis is derived foremost from experience, both personal and literature-based. In the first instance, knowledge of the linkage between one's own diagnoses and individual patient outcomes is required, to validate the role of one's own interpretations in the clinical course of patients. Experience comes from seeing this linkage first hand, from which hopefully comes wisdom and, ultimately, good clinical judgment. In the second instance, reading the literature and learning from experts is required. Only a minority of the relevant literature is published in pathology journals to which one may subscribe. A substantial portion of major papers relevant to the practice of anatomic pathology are published in collateral clinical specialty journals devoted to specific disease areas or organs. Active effort is therefore required to seek out the literature beyond the domain of pathology journals. In examining the published literature, the essential question then becomes: Does the practice of anatomic pathology fulfill the tenets of 'evidence-based medicine' (EBM)? If the pinnacle of EBM is 'systematic review of randomized clinical trials, with or without meta-analysis', then anatomic pathology falls far short. Our published literature is largely observational in nature, with reports of case series (with or without statistical analysis) constituting the majority of our 'evidence base'. Moreover, anatomic pathology is subject to 'interobserver variation', and potentially to 'error'. Taken further, individual interpretation of tissue samples is not an objective endeavor, and it is not easy to fulfill the role of a 'gold standard'. Both for rendering of an overall interpretation, and for providing the semi-quantitative and quantitative numerical 'scores' which support evidence-based clinical treatment algorithms, the Pathologist has to exercise a high level of interpretive judgment. Nevertheless, the contribution of anatomic pathology to 'EBM' is remarkably strong. To the extent that our judgmental interpretations become data, our tissue interpretations become the arbiters of patient care management decisions. In a more global sense, we support highly successful cancer screening programs, and play critical roles in the multidisciplinary management of complex patients. The true error is for the clinical practitioners of 'EBM' to forget the contribution to the supporting evidence base of the physicians that are Anatomic Pathologists. Finally, the academic productivity of pathology faculty who operate in the clinical realm must be considered. A survey of six North American academic pathology departments reveals that 26% of all papers published in 2005 came from 'unfunded' clinical faculty. While it is likely that their academic productivity is lower than that of 'funded' research faculty, the contribution of clinical faculty to the knowledge base for the practice of modern medicine, and to the academic reputation of the department, must not be overlooked. The ability of clinical faculty in academic departments of pathology to pursue original scholarship must be supported if our specialty is to retain its preeminence as an investigative scientific discipline in the age of EBM.

Surgical specimen identification errors: a new measure of quality in surgical care

BACKGROUND

Communication errors are the primary factor contributing to all types of sentinel events including those involving surgical patients. One type of communication error is mislabeled specimens. The extent to which these errors occur is poorly quantified. We designed a study to measure the incidence and type of specimen identification errors in the surgical patient population.

METHODS

We performed a prospective cohort study that included all patients who underwent surgery in an outpatient clinic or hospital operating room and for whom a pathology specimen was sent to the laboratory. The study took place during a 6-month period (October 2004 to April 2005) at an urban, academic medical center. The study's main end-points were the incidence and type of specimen labeling errors in the hospital operating room and the outpatient clinic. The specimen was the unit of analysis. All specimens were screened for "identification errors," which, for the purposes of this study, were defined as any discrepancy between information on the specimen requisition form and the accompanying labeled specimen received in the laboratory. Errors were stratified by the type of identification error, source, location, and type of procedure.

RESULTS

A total of 21,351 surgical specimens were included in the analysis. There were 91 (4.3/1000) surgical specimen identification errors (18, specimen not labeled; 16, empty container; 16, laterality incorrect; 14, incorrect tissue site; 11, incorrect patient; 9, no patient name; and 7, no tissue site). Identification errors occurred in 0.512% of specimens originating from an outpatient clinic (53/10,354 specimens) and 0.346% of specimens originating from an operating room (38/10,997 specimens). Procedures involving the breast were the most common type to involve an identification error (breast = 11, skin = 10, colon = 8); in addition, 59.3% (54/91) of errors were associated with a biopsy procedure. Follow-up was complete in all cases found to have an identification error.

CONCLUSIONS

Surgical specimen identification errors are common and pose important risks to all patients. In our study, these events occurred in 4.3 per 1000 surgical specimens or an annualized rate of occurrence of 182 mislabeled specimens per year. Given the frequency with which these errors occur and their potential effect on patients, the rate of surgical specimen identification errors may be an important measure of patient safety. Strategies to reduce the rate of these errors should be a research priority.

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.

Diagnostic ‘errors’ in anatomical pathology: relevance to Australian laboratories

Failure to recognise that anatomical pathology diagnosis is a process of cognitive interpretation of the morphological features present in a small tissue sample has led to the public misperception that the process is infallible. The absence of a universally accepted definition of diagnostic error makes comparison of error rates impossible and one large study of laboratories in the United States shows a significant error rate of about 5%, most of which have no major impact on patient management. A recent review of the work of one pathologist in New South Wales confirms a lack of appreciation in medical administration that variable diagnostic thresholds result in an inherent fallibility of anatomical pathology diagnoses. The outcome of the review emphasises the need to educate both public and non-pathology colleagues of the nature of our work and brings into consideration the requirement to establish baseline error rates for Australian laboratories and the role of the Royal College of Pathologists of Australasia (RCPA) in developing fair and unbiased protocols for review of diagnostic errors. The responsibility of ensuring that diagnostic error rates are kept to the minimum is a shared one. Area health services must play their part by seeking to ensure that pathologists in any laboratory are not overworked and have adequate support and back-up from pathologists with expertise in specialised areas. It has been clearly enunciated by the Royal College of Pathologists in the United Kingdom that it is not safe for any histopathology service to be operated single-handedly by one histopathologist. Service managers and clinicians have to understand that country pathologists cannot provide the full range and depth of pathology expertise in the many clinical subspecialty areas that are often practised in non-metropolitan areas. Attending clinicians share the responsibility of accepting proffered pathology diagnoses only if it conforms to the clinical context. Pathology laboratories must continue to develop and maintain best-practice protocols and conduct periodic reviews of diagnosis, cytology-histology concordance, frozen section/permanent section correlations, conference reviews, intra and interdepartmental consultations, participate in external quality assurance programs and maintain ongoing education for all laboratory staff.

Effectiveness of Toyota process redesign in reducing thyroid gland fine-needle aspiration error

Our objective was to determine whether the Toyota Production System process redesign resulted in diagnostic error reduction for patients who underwent cytologic evaluation of thyroid nodules. In this longitudinal, nonconcurrent cohort study, we compared the diagnostic error frequency of a thyroid aspiration service before and after implementation of error reduction initiatives consisting of adoption of a standardized diagnostic terminology scheme and an immediate interpretation service. A total of 2,424 patients underwent aspiration. Following terminology standardization, the false-negative rate decreased from 41.8% to 19.1% (P = .006), the specimen nondiagnostic rate increased from 5.8% to 19.8% (P < .001), and the sensitivity increased from 70.2% to 90.6% (P < .001). Cases with an immediate interpretation had a lower noninterpretable specimen rate than those without immediate interpretation (P < .001). Toyota process change led to significantly fewer diagnostic errors for patients who underwent thyroid fine-needle aspiration.

Variability of practice in anatomic pathology and its effect on patient outcomes

Variability in the delivery of medical care negatively affects patient outcomes and contributes to escalating health care costs. Such heterogeneity exists on geographic, provider-related, institutional, and financial levels. Efforts to reduce it have resulted in the development of evidence-based clinical practice guidelines that have been only inconsistently adopted. Testing patterns in anatomic pathology (AP) also manifest considerable inconsistency, further contributing to suboptimal health outcomes and increased costs. Test variability in AP can be identified in its clinician-dependent preanalytic aspect and in the analytic phase as well, including the gross prosection of specimens, their processing, and reporting formats. To address selected facets of these issues, pathologists have developed practice guidelines that generally are based on "expert" opinion, representing the weakest form of evidence. Interpretative variability in AP has been investigated in numerous published studies that have measuring the "kappa statistic." Few of those analyses have addressed the impact of diagnostic disagreement on patient care; in addition, proposed and effective methods to reduce interpretative variability have only rarely been included.