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PubMed1997

Latent variable modeling of diagnostic accuracy.

Latent class analysis has been applied in medical research to assessing the sensitivity and specificity of diagnostic tests/diagnosticians. In these applications, a dichotomous latent variable corresponding to the unobserved true disease status of the patients is assumed. Associations among multiple diagnostic tests are attributed to the unobserved heterogeneity induced by the latent variable, and inferences for the sensitivities and specificities of the diagnostic tests are made possible even though the true disease status is unknown. However, a shortcoming of this approach to analyses of diagnostic tests is that the standard assumption of conditional independence among the diagnostic tests given a latent class is contraindicated by the data in some applications. In the present paper, models incorporating dependence among the diagnostic tests given a latent class are proposed. The models are parameterized so that the sensitivities and specificities of the diagnostic tests are simple functions of model parameters, and the usual latent class model obtains as a special case. Marginal models are used to account for the dependencies within each latent class. An accelerated EM gradient algorithm is demonstrated to obtain maximum likelihood estimates of the parameters of interest, as well as estimates of the precision of the estimates.

Analysis of Variance↗
PubMed1998

[Diagnostic procedure in patients with suspected lung cancer. Results of combined evaluation by thoracic surgery and pulmonary medicine specialists].

During the last 50 years, the 5-year survival of lung cancer patients has been unchanged at 5%. As the prognosis for patients with operable nonsmall cell lung cancer (NSCLC) is much better, the diagnostic examination of tumour suspicious lesions with secondary judgement of operability in NSCLC is an important subject. This study focuses on the diagnostic process. During the years 1991-1993, 467 consecutive patients with pulmonary tumour suspicious lesions were prospectively followed at the Department of Pulmonary Medicine and the Department of Thoracic Surgery, Bispebjerg Hospital. In 40% of the patients, the diagnostic delay was longer than 30 days. Fiberbronchoscopy and fine needle biopsy were the most important diagnostic tests with an accuracy of approx. 90% for both central and peripheral lesions. Benign lesions comprised 19% of all, while the prevalence of squamous cell carcinoma, adenocarcinoma, small-cell carcinoma and large-cell carcinoma was respectively 21%, 26%, 15% and 18% of the malignant infiltrates. Histological diagnosis was not achieved in 104 patients. Histological diagnosis was achieved in most patients, but the diagnostic process was slow. A faster diagnostic process is to be aimed for and can, hopefully, be achieved by accomplishing diagnostic standards as just proposed by the Danish Lung Cancer Group.

Adenocarcinoma↗
PubMed1998

Diagnostic approach to acute pulmonary embolism in a general hospital. A two-year analysis.

BACKGROUND: Several approaches have been proposed for the diagnosis of acute pulmonary embolism (PE), but little is known about the strategies effectively used in daily clinical practice. METHODS: Retrospective evaluation of the diagnostic strategy used in our institution in the patients (pts) discharged between January 1st 1995 and December 31st 1996 with diagnostic code 415.1, corresponding to acute PE in the International Classification of Disease. RESULTS: One-hundred-twenty-seven patients (49 M; 78 F; mean age: 71.5 +/- 15 years; range: 25-95) were identified. Electrocardiogram, chest X-ray, blood gas analysis and plasma D-dimer measurement were performed in 122 (96%), 121 (95%), 114 (90%) and 86 (68%) pts, respectively. Out of the 102 pts surviving the initial phase (early mortality: 20%), 83 (81%) underwent lung scintigraphy, 10 (10%) spiral CT scanning and 2 (2%) pulmonary angiography, while 7 (7%) were treated directly. Thirty of the 83 pts undergoing lung scintigraphy had non-diagnostic results, but only 8 of them underwent further investigation (with spiral CT in 6 cases and pulmonary angiography in 2 cases). Transthoracic echocardiography and ultrasonography of the lower limbs were used in 49 (48%) and 74 (73%) pts respectively, for diagnostic confirmation and to search for the embolic source. CONCLUSIONS: At our institution, where multiple and modern diagnostic facilities are available, ventilation/perfusion lung scanning still represents the most frequently used imaging technique. Spiral CT is employed quite often as an alternative to either lung scintigraphy or pulmonary angiography which, in turn, is used very seldom. Ultrasonography of the lower-limbs is widely utilized (although not in a serial manner and only as a second-line test), while the role of echocardiography appears to be marginal. Spiral CT, pulmonary angiography and lower-limb ultrasonography showed high diagnostic accuracy, while the accuracy of lung scintigraphy and echocardiography was confirmed as being suboptimal. However, due to the retrospective design of our study and the characteristics of our population, these results cannot be extrapolated to pts referred for suspected acute PE, in whom further investigations are thus warranted in order to identify the most cost-effective diagnostic approach.

Acute Disease↗
PubMed1998

Training in diagnostic ultrasound: essentials, principles and standards. Report of a WHO Study Group.

Diagnostic ultrasound is a rapidly developing imaging technology widely used in both industrialized and developing countries. For certain diagnostic applications, ultrasound has replaced commonly used radiographic imaging techniques as the method of choice, and it has also made possible new areas of diagnostic investigation. Moreover, equipment for ultrasound imaging tends to be cheaper and more widely available than imaging equipment requiring the use of ionizing radiation. This combination of factors has resulted in the proliferation of diagnostic ultrasound units, and in some cases their use by individuals without proper training, or under conditions of inadequate control. This report, the outcome of a recent WHO Study Group, is concerned with the essentials, principles, and standards of training for this important technology. The Study Group has analysed problems in the effective use of diagnostic ultrasound and reviewed current training practice worldwide. For the first time, outlines of recommended training curricula for the general, advanced, and specialized use of diagnostic ultrasound are presented. Recommended standards for training programmes, training centres, and the training process are also discussed. The report highlights the role played by professional societies, but also calls attention to the need for appropriate legislation and regulation. The Study Group's recommendations are relevant to all those involved in the use of diagnostic ultrasound technology, even in countries where existing standards of practice are high. In addition to ultrasound specialists, the report should be of particular interest to those responsible for medical education or for formulating policies regarding the use of health technology.

Allied Health Personnel↗
PubMed1999

Diagnostic yield of the comprehensive assessment of developmental delay/mental retardation in an institute of child neuropsychiatry.

The Consensus Conference of the American College of Medical Genetics has established guidelines regarding the evaluation of patients with mental retardation (MR) [Curry et al., Am. J. Med. Genet. 72:468-477, 1997]. They emphasized the high diagnostic utility of cytogenetic studies and of neuroimaging in certain clinical settings. However, data on the diagnostic yield of these studies in well-characterized populations of individuals with MR are scant. Majnemer and Shevell [J. Pediatr. 127:193-199, 1995] attained a diagnostic yield of 63%. However, this study included only 60 patients and the classification included pathogenetic and causal groups. The Stella Maris Institute has evaluated systematically patients with developmental delay (DD)/MR and performed various laboratory studies and neuroimaging in almost all patients. We report a retrospective analysis of the diagnostic yield of 120 consecutive patients observed at our Institute during the first 6 months of 1996. There were 77 males and 43 females; 47 were mildly delayed (IQ 70-50), 31 were moderately delayed (IQ 50-35), and 42 were severely delayed (IQ 35-20). Diagnostic studies (history, physical examination, standard cytogenetics, fragile X testing, molecular studies, electroencephalography, electromyography, nerve conduction studies, neuroimaging, and metabolic screening tests) yielded a causal diagnosis in 50 (41.6%) and a pathogenetic diagnosis in 47 (39.2%) of the 120 patients. Causal categories included chromosomal abnormalities (14), Fra(X) syndromes (4), known MCA/MR syndromes (19), fetal environmental syndromes (1), neurometabolic (3) disorders, neurocutaneous (3) disorders, hypoxic-ischemic encephalopathy (3), other encephalopathies (1), and congenital bilateral perisylvian syndrome (2). Pathogenetic categories included idiopathic MCA/MR syndromes (35), epileptic syndromes (10), and isolated lissencephaly sequence (2). Diagnostic yield did not differ across categories and degree of DD. Our results, while confirming the diagnostic utility of cytogenetic/molecular genetic, and neuroimaging studies, suggest the usefulness of accurate electroencephalogram recordings, and stress the importance of a thorough physical examination. Referral to a university child neurology and psychiatry service, where a comprehensive assessment with a selected battery of investigations is possible, yields etiologic findings in a high percentage of DD/MR patients, with important implications for management, prognosis and recurrence risk estimate.

Adolescent↗
PubMed2025

Bacteriophages as a modern diagnostic tool: innovations, applications and challenges.

Bacteriophages, viruses that specifically infect bacteria, have emerged as a valuable tool in diagnostics due to their unique specificity and adaptability. This review explores the diverse applications of bacteriophages in diagnostic methods, from traditional phage typing to advanced molecular techniques such as phage display and PCR-based diagnostics. It highlights their use in identifying bacterial strains, monitoring fermentation processes, and diagnosing critical conditions like tuberculosis, MRSA infections, and cancer. Innovations such as phage-based biosensors and reporter phages enhance the speed and precision of diagnostics, offering significant advantages over traditional methods. Challenges, including bacterial resistance and immune responses to phages, are also discussed alongside strategies for mitigation, such as phage cocktails and engineering. Integrating phage technology with modern bioscience holds promise for addressing antibiotic resistance and revolutionizing clinical and industrial diagnostics. This comprehensive analysis underscores the potential of bacteriophages to transform the diagnostic landscape while identifying areas requiring further research and development.

Bacteriophages↗
PubMed2023

Phenotypic presentation of Mendelian disease across the diagnostic trajectory in electronic health records.

PURPOSE: To investigate the phenotypic presentation of Mendelian disease across the diagnostic trajectory in the electronic health record (EHR). METHODS: We applied a conceptual model to delineate the diagnostic trajectory of Mendelian disease to the EHRs of patients affected by 1 of 9 Mendelian diseases. We assessed data availability and phenotype ascertainment across the diagnostic trajectory using phenotype risk scores and validated our findings via chart review of patients with hereditary connective tissue disorders. RESULTS: We identified 896 individuals with genetically confirmed diagnoses, 216 (24%) of whom had fully ascertained diagnostic trajectories. Phenotype risk scores increased following clinical suspicion and diagnosis (P < 1&#xa0;&#xd7; 10-4, Wilcoxon rank sum test). We found that of all International Classification of Disease-based phenotypes in the EHR, 66% were recorded after clinical suspicion, and manual chart review yielded consistent results. CONCLUSION: Using a novel conceptual model to study the diagnostic trajectory of genetic disease in the EHR, we demonstrated that phenotype ascertainment is, in large part, driven by the clinical examinations and studies prompted by clinical suspicion of a genetic disease, a process we term diagnostic convergence. Algorithms designed to detect undiagnosed genetic disease should consider censoring EHR data at the first date of clinical suspicion to avoid data leakage.

Humans↗
PubMed2003

Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative.

OBJECTIVE: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy in order to allow readers to assess the potential for bias in the study and to evaluate its generalisability. METHODS: The Standards for Reporting of Diagnostic Accuracy (STARD) steering committee searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and extracted potential items into an extensive list. Researchers, editors, and members of professional organizations shortened this list during a two-day consensus meeting with the goal of developing a checklist and a generic flow diagram for studies of diagnostic accuracy. RESULTS: The search for published guidelines regarding diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. At the consensus meeting, participants shortened the list to 25 items, using evidence on bias whenever available. A prototypical flow diagram provides information about the method of patient recruitment, the order of test execution and the numbers of patients undergoing the test under evaluation, the reference standard or both. CONCLUSIONS: Evaluation of research depends on complete and accurate reporting. If medical journals adopt the checklist and the flow diagram, the quality of reporting of studies of diagnostic accuracy should improve to the advantage of the clinicians, researchers, reviewers, journals, and the public.

Algorithms↗
PubMed2003

Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative.

AIM: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy in order to allow readers to assess the potential for bias in a study and to evaluate the general isability of its results. METHODS: The standards for reporting of diagnostic accuracy (STARD) steering committee searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and extracted potential items into an extensive list. Researchers, editors, and members of professional organisations shortened this list during a 2 day consensus meeting with the goal of developing a checklist and a generic flow diagram for studies of diagnostic accuracy. RESULTS: The search for published guidelines about diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. At the consensus meeting, participants shortened the list to a 25-item checklist, by using evidence whenever available. A prototype of a flow diagram provides information about the method of recruitment of patients, the order of test execution and the numbers of patients undergoing the test under evaluation, the reference standard, or both. CONCLUSIONS: Evaluation of research depends on complete and accurate reporting. If medical journals adopt the checklist and the flow diagram, the quality of reporting of studies of diagnostic accuracy should improve to the advantage of clinicians, researchers, reviewers, journals, and the public.

Algorithms↗
PubMed2004

Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative.

OBJECTIVE: Our aim was to improve the accuracy and completeness of reporting of studies of diagnostic accuracy in order to allow readers to assess the potential for bias in a study and to evaluate the generalizability of its results. METHODS: The Standards for Reporting of Diagnostic Accuracy (STARD) steering committee searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and extracted potential items into an extensive list. Researchers, editors and members of professional organizations shortened this list during a 2-day consensus meeting with the goal of developing a checklist and a generic flow diagram for studies of diagnostic accuracy. RESULTS: The search for published guidelines about diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. At the consensus meeting, participants shortened the list to a 25-item checklist, by using evidence whenever available. A prototype of a flow diagram provides information about the method of recruitment of patients, the order of test execution and the numbers of patients undergoing the test under evaluation and/or the reference standard. CONCLUSIONS: Evaluation of research depends on complete and accurate reporting. If medical journals adopt the checklist and the flow diagram, the quality of reporting of studies of diagnostic accuracy should improve, to the advantage of clinicians, researchers, reviewers, journals and the public.

Bias↗
PubMed2003

Accounting for nonignorable verification bias in assessment of diagnostic tests.

A "gold" standard test, providing definitive verification of disease status, may be quite invasive or expensive. Current technological advances provide less invasive, or less expensive, diagnostic tests. Ideally, a diagnostic test is evaluated by comparing it with a definitive gold standard test. However, the decision to perform the gold standard test to establish the presence or absence of disease is often influenced by the results of the diagnostic test, along with other measured, or not measured, risk factors. If only data from patients who received the gold standard test were used to assess the test performance, the commonly used measures of diagnostic test performance--sensitivity and specificity--are likely to be biased. Sensitivity would often be higher, and specificity would be lower, than the true values. This bias is called verification bias. Without adjustment for verification bias, one may possibly introduce into the medical practice a diagnostic test with apparent, but not truly, high sensitivity. In this article, verification bias is treated as a missing covariate problem. We propose a flexible modeling and computational framework for evaluating the performance of a diagnostic test, with adjustment for nonignorable verification bias. The presented computational method can be utilized with any software that can repetitively use a logistic regression module. The approach is likelihood-based, and allows use of categorical or continuous covariates. An explicit formula for the observed information matrix is presented, so that one can easily compute standard errors of estimated parameters. The methodology is illustrated with a cardiology data example. We perform a sensitivity analysis of the dependency of verification selection process on disease.

Aged↗
PubMed2003

Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative.

OBJECTIVE: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy, to allow readers to assess the potential for bias in a study, and to evaluate a study's generalisability. METHODS: The Standards for Reporting of Diagnostic Accuracy (STARD) steering committee searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and extracted potential items into an extensive list. Researchers, editors, and members of professional organisations shortened this list during a two day consensus meeting, with the goal of developing a checklist and a generic flow diagram for studies of diagnostic accuracy. RESULTS: The search for published guidelines about diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. At the consensus meeting, participants shortened the list to a 25 item checklist, by using evidence, whenever available. A prototype of a flow diagram provides information about the method of patient recruitment, the order of test execution, and the numbers of patients undergoing the test under evaluation and the reference standard, or both. CONCLUSIONS: Evaluation of research depends on complete and accurate reporting. If medical journals adopt the STARD checklist and flow diagram, the quality of reporting of studies of diagnostic accuracy should improve to the advantage of clinicians, researchers, reviewers, journals, and the public.

Algorithms↗
PubMed2003

Towards complete and accurate reporting of studies of diagnostic accuracy: The STARD Initiative.

OBJECTIVE: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy, to allow readers to assess the potential for bias in the study and to evaluate its generalisability. METHODS: The Standards for Reporting of Diagnostic Accuracy (STARD) steering group searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and extracted potential items into an extensive list. Researchers, editors, and members of professional organisations shortened this list during a two-day consensus meeting with the goal of developing a checklist and a generic flow diagram for studies of diagnostic accuracy. RESULTS: The search for published guidelines regarding diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. At the consensus meeting, participants shortened the list to a 25-item checklist, using evidence, whenever available. A prototypical flow diagram provides information about the method of patient recruitment, the order of test execution and the numbers of patients undergoing the test under evaluation, the reference standard or both. CONCLUSIONS: Evaluation of research depends on complete and accurate reporting. If medical journals adopt the checklist and the flow diagram, the quality of reporting of studies of diagnostic accuracy should improve to the advantage of the clinicians, researchers, reviewers, journals, and the public.

Algorithms↗
PubMed2003

Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative.

BACKGROUND: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy in order to allow readers to assess the potential for bias in a study and to evaluate the generalizability of its results. METHODS: The Standards for Reporting of Diagnostic Accuracy (STARD) steering committee searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and extracted potential items into an extensive list. Researchers, editors and members of professional organizations shortened this list during a 2-day consensus meeting with the goal of developing a checklist and a generic flow diagram for studies of diagnostic accuracy. RESULTS: The search for published guidelines regarding diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. At the consensus meeting, participants shortened the list to 25 items, using evidence on bias whenever available. A prototypical flow diagram provides information about the method of patient recruitment, the order of test execution and the numbers of patients undergoing the test under evaluation, the reference standard or both. CONCLUSIONS: Evaluation of research depends on complete and accurate reporting. If medical journals adopt the checklist and the flow diagram, the quality of reporting of studies of diagnostic accuracy should improve to the advantage of the clinicians, researchers, reviewers, journals and the public.

Diagnostic Errors↗
PubMed2003

Toward complete and accurate reporting of studies of diagnostic accuracy. The STARD initiative.

Our objective was to improve the accuracy and completeness of reporting of studies of diagnostic accuracy, to allow readers to assess the potential for bias in the study, and to evaluate its generalizability. The Standards for Reporting of Diagnostic Accuracy Steering Committee searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and extracted potential items into an extensive list. Researchers, editors, and members of professional organizations shortened this list during a 2-day consensus meeting with the goal of developing a checklist and a generic flow diagram for studies of diagnostic accuracy. The search for published guidelines regarding diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. At the consensus meeting, participants shortened the list to a 25-item checklist, using evidence whenever available. A prototypical flow diagram provides information about the method of patient recruitment, the order of test execution, and the numbers of patients undergoing the test under evaluation, the reference standard, or both. Evaluation of research depends on complete and accurate reporting. If medical journals adopt the checklist and the flow diagram, the quality of reporting of studies of diagnostic accuracy should improve, to the advantage of clinicians, researchers, reviewers, journals, and the public.

Algorithms↗
PubMed2003

Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative.

OBJECTIVE: To improve the accuracy and completeness of reporting of studies of diagnostic accuracy in order to allow readers to assess the potential for bias in a study and to evaluate the generalisability of its results. METHODS: The Standards for Reporting of Diagnostic Accuracy (STARD) steering committee searched the literature to identify publications on the appropriate conduct and reporting of diagnostic studies and extracted potential items into an extensive list. Researchers, editors, and members of professional organisations shortened this list during a 2-day consensus meeting with the goal of developing a checklist and a generic flow diagram for studies of diagnostic accuracy. RESULTS: The search for published guidelines about diagnostic research yielded 33 previously published checklists, from which we extracted a list of 75 potential items. At the consensus meeting, participants shortened the list to a 25-item checklist, by using evidence whenever available. A prototype of a flow diagram provides information about the method of recruitment of patients, the order of test execution and the numbers of patients undergoing the test under evaluation, the reference standard, or both. CONCLUSIONS: Evaluation of research depends on complete and accurate reporting. If medical journals adopt the checklist and the flow diagram, the quality of reporting of studies of diagnostic accuracy should improve to the advantage of clinicians, researchers, reviewers, journals, and the public.

Algorithms↗
PubMed2002

The hypersensitivity pneumonitis diagnostic index: use of non-invasive testing to diagnose hypersensitivity pneumonitis in metalworkers.

BACKGROUND: Since 1993, several outbreaks of hypersensitivity pneumonitis (HP) have been reported in metalworkers. We report the largest outbreak of HP in metalworkers yet known. It occurred in a Connecticut factory that produces precision parts for the aerospace industry. The workers typically presented with systemic and respiratory problems ("sick fatigue," myalgias, cough, dyspnea, wheezing, and chest tightness). They had variable findings on clinical tests, which complicated diagnosis. An HP diagnostic index was developed to help reduce the uncertainties in case identification. METHODS: Data from 16 biopsy-confirmed cases and 14 non-HP patients were compared, and the HP diagnostic index was derived using variables that best discriminated between the two groups. The index is based on (a) work-related symptoms, (b) dry crackles on auscultation, (c) restrictive spirometry, (d) decreased diffusion capacity and/or increased A-a oxygen gradient, (e) elevated erythrocyte sedimentation rate, (f) abnormal radiographic images, and (g) abnormal gallium scans. We then applied the HP diagnostic index and, for comparison, the "Kenosha epidemiological case criteria" (developed during a recent HP outbreak in an automobile factory) to our data set. RESULTS: The HP diagnostic index and the Kenosha criteria confirmed HP in overlapping sets of 36 and 34 patients, respectively, that were both in good agreement with the clinical diagnoses. CONCLUSIONS: The HP diagnostic index relies less heavily on symptoms, subjective evaluations, and invasive tests than the Kenosha criteria, but both identified similar subsets of the 61 patients as having HP. The HP diagnostic index could provide a useful tool in future HP outbreaks, which are increasingly being recognized in metalworking facilities.

Alveolitis, Extrinsic Allergic↗
PubMed2004

Adenocarcinoma in situ of the uterine cervix: screening and diagnostic errors in Papanicolaou smears.

BACKGROUND: Little attention has been given to the reasons for failure to detect adenocarcinoma in situ (AIS) of the uterine cervix in Papanicolaou (Pap) smears. In the current study, the authors examined a series of screening or diagnostic errors in cases in which the final histologic diagnosis was either AIS or AIS combined with a high-grade squamous intraepithelial lesion (AIS + HSIL). METHODS: Smears obtained in the 3 years before histologically proven AIS or AIS + HSIL was diagnosed and within a specified 6-year period (1993-1998) were reviewed and reclassified. All were conventional Pap smears. The smears studied were those with a review diagnosis of possible or definite high-grade epithelial abnormality that initially were reported by a cytotechnologist to be negative (screening error) or that were reported by a pathologist to be negative, unsatisfactory, or indicative of a low-grade epithelial abnormality (diagnostic error). A semiquantitative, blinded assessment of the frequency of cytologic criteria for the diagnosis of AIS was made for smears with erroneous diagnoses compared with a series of smears that yielded true-positive findings. RESULTS: Sampling errors, which were defined as cases in which smears did not have sufficient evidence for a diagnosis of possible or definite AIS or HSIL on review, accounted for 35.1% and 36% of all smears from patients with a biopsy diagnosis of AIS and patients with a biopsy diagnosis of AIS + HSIL, respectively. With regard to AIS, there were 3 screening errors and 5 diagnostic errors, accounting for 10.4% of 77 smears. Minimal, poorly preserved material was evident in four smears, including three smears with only one sheet of abnormal glandular cells. In four other smears, there was a moderate amount of adequately preserved glandular material, mainly in large sheets, with varying degrees of crowding and hyperchromasia. With regard to AIS + HSIL, there were 6 screening errors and 6 diagnostic errors, accounting for 13.5% of 89 smears. In those smears, there generally was a moderate amount of abnormal material in the form of crowded groups of suboptimally preserved, hyperchromatic squamous cells. Only two of those smears yielded findings of possible abnormal glandular cells. Only 3 of 20 errors occurred in smears that were examined during the last 3 years of the study. In the semiquantitative assessment, smears with erroneous findings were shown to contain far less abnormal material than true-positive smears and to exhibit a corresponding paucity of diagnostic criteria. CONCLUSIONS: Sampling errors were the main cause of false-negative reports in cases of AIS and AIS + HSIL. The primary factors that contributed to screening or diagnostic errors in AIS were minimal, poorly preserved abnormal material and an overly conservative approach to the assessment of unusual large sheets or aggregates of glandular cells. With regard to AIS + HSIL, most laboratory errors were related to the presence of crowded groups of squamous epithelial cells. There were fewer errors in the last 3 years of the study, raising the possibility of improvement over time.

Adenocarcinoma↗