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Diagnostic Errors (diagnostic + error)
Selected AbstractsLatent Class Modeling Approaches for Assessing Diagnostic Error without a Gold Standard: With Applications to p53 Immunohistochemical Assays in Bladder TumorsBIOMETRICS, Issue 2 2001Paul S. Albert Summary. Improved characterization of tumors for purposes of guiding treatment decisions for cancer patients will require that accurate and reproducible assays be developed for a variety of tumor markers. No gold standards exist for most tumor marker assays. Therefore, estimates of assay sensitivity and specificity cannot be obtained unless a latent class model-based approach is used. Our goal in this article is to estimate sensitivity and specificity for p53 immunohistochemical assays of bladder tumors using data from a reproducibility study conducted by the National Cancer Institute Bladder Tumor Marker Network. We review latent class modeling approaches proposed by previous authors, and we find that many of these approaches impose assumptions about specimen heterogeneity that are not consistent with the biology of bladder tumors. We present flexible mixture model alternatives that are biologically plausible for our example, and we use them to estimate sensitivity and specificity for our p53 assay example. These mixture models are shown to offer an improvement over other methods in a variety of settings, but we caution that, in general, care must be taken in applying latent class models. [source] Review article: Indications for thoracolumbar imaging in blunt trauma patients: A review of current literatureEMERGENCY MEDICINE AUSTRALASIA, Issue 2 2009Enda O'Connor Abstract Thoracolumbar spine injury is a common complication of blunt multitrauma and up to one third of fractures are associated with spinal cord dysfunction. Delayed fracture diagnosis increases the risk of neurological complications. While validated screening guidelines exist for traumatic c-spine injury equivalent guidelines for thoracolumbar screening are lacking. We conducted a literature review evaluating studies of thoracolumbar injury in trauma patients to generate indications for thoracolumbar imaging. We performed MEDLINE and Pubmed searches using MeSH terms "Wounds, Nonpenetrating", "Spinal Fractures", "Spinal Injuries" and "Diagnostic Errors", MeSH/subheading terms "Thoracic Vertebrae/injuries" and "Lumbar Vertebrae/injuries" and keyword search terms "thoracolumbar fractures", "thoracolumbar injuries", "thoracolumbar trauma", "missed diagnoses" and "delayed diagnoses". Limits and inclusion criteria were defined prior to searching. We evaluated 16 articles; 5 prospective observational studies (1 cohort study) and 11 retrospective observational studies. Predictors of TL injury in prospective studies , high-risk injury mechanism, distracting injury, impaired cognition, symptoms/signs of vertebral fracture and known cervical fracture , were defined and used to construct a decision algorithm, which in a total of 14189 trauma patients from all eligible studies recommended TL screening in 856(99.1%) of 864 patients with TL fractures and would probably have directed TL imaging in the remaining 8 patients. There is limited low level evidence guiding surveillance TL imaging in adult blunt trauma patients. Despite this, we propose and evaluate an algorithm with a high negative predictive value for TL fractures. This should be incorporated into spinal injury assessment protocols. [source] Paroxysmal Motor Disorders of Sleep: The Clinical Spectrum and Differentiation from EpilepsyEPILEPSIA, Issue 11 2006Christopher P. Derry Summary:, The diagnosis of paroxysmal events in sleep represents a significant challenge for the clinician, with the distinction of nocturnal epilepsy from nonepileptic sleep disorders often the primary concern. Diagnostic error or uncertainty is not uncommon in this situation, particularly with respect to nocturnal frontal lobe epilepsy (NFLE), which has a variable and often unusual presentation. Such errors can be minimized if the range of nonepileptic disorders with motor activity in sleep is fully appreciated. Here we review these disorders, before discussing the important clinical and electrographic features that allow their accurate differentiation from seizures. Particular emphasis is placed on the differentiation of nocturnal frontal lobe epilepsy from non,rapid eye movement (NREM) arousal disorders and other parasomnias. The value of recording episodes with video EEG polysomnography is discussed. [source] Profiles in Patient Safety: A "Perfect Storm" in the Emergency DepartmentACADEMIC EMERGENCY MEDICINE, Issue 8 2007CCFP(EM), Samuel G. Campbell MB Correct and rapid diagnosis is pivotal to the practice of emergency medicine, yet the chaotic and ill-structured emergency department environment is fertile ground for the commission of diagnostic error. Errors may result from specific error-producing conditions (EPCs) or, more frequently, from an interaction between such conditions. These EPCs are often expedient and serve to shorten the decision making process in a high-pressure environment. Recognizing that they will inevitably exist, it is important for clinicians to understand and manage their dangers. The authors present a case of delayed diagnosis resulting from the interaction of a number of EPCs that produced a "perfect" situation to produce a missed or delayed diagnosis. They offer practical suggestions whereby clinicians may decrease their chances of becoming victims of these influences. [source] Incorrect and incomplete coding and classification of diabetes: a systematic reviewDIABETIC MEDICINE, Issue 5 2010M. A. Stone Diabet. Med. 27, 491,497 (2010) Abstract Aims, To conduct a systematic review to identify types and implications of incorrect or incomplete coding or classification within diabetes or between diabetes and other conditions; also to determine the availability of evidence regarding frequency of occurrence. Methods, Medical Subject Headings (MeSH) and free-text terms were used to search relevant electronic databases for papers published to the end of August 2008. Two researchers independently reviewed titles and abstracts and, subsequently, the full text of potential papers. Reference lists of selected papers were also reviewed and authors consulted. Three reviewers independently extracted data. Results, Seventeen eligible studies were identified, including five concerned with distinguishing between Type 1 and Type 2 diabetes. Evidence was also identified regarding: the distinction between diabetes and no-diabetes, failure to specify type of diabetes, and diagnostic errors or difficulties involving maturity-onset diabetes of the young, latent autoimmune diabetes in adults, pancreatic diabetes, persistence of foetal haemoglobin and acquired immune deficiency syndrome (AIDS). The sample was too heterogeneous to derive accurate information about frequency, but our findings suggested that misclassification occurs most commonly in young people. Implications relating to treatment options and risk management were highlighted, in addition to psychological and financial implications and the potential impact on the validity of quality of care evaluations and research. Conclusions, This review draws attention to the occurrence and implications of incorrect or incomplete coding or classification of diabetes, particularly in young people. A pragmatic and clinically relevant approach to classification is needed to assist those involved in making decisions about types of diabetes. [source] Pleomorphic adenoma: Cytologic variations and potential diagnostic pitfallsDIAGNOSTIC CYTOPATHOLOGY, Issue 1 2009Uma Handa M.D. Abstract The diverse morphological features encountered in pleomorphic adenoma (PA) may cause diagnostic errors in fine needle aspiration cytology (FNAC). The present study was performed to evaluate the variations in the cytological features of pleomorphic adenoma and to assess the efficacy of FNAC in its diagnosis. Fifty cases diagnosed as PA on FNAC were retrieved from the records of the Pathology Department. Cytologic smears and sections were reviewed and the cytologic diagnoses were compared with the definitive histologic diagnoses. In cases correctly diagnosed on aspiration, morphological variables like patterns of the epithelial component, type and extent of the mesenchymal matrix, metaplastic cells, hyaline globules, cystic change, giant cells, crystalline deposits, nuclear inclusions/grooves, and nuclear atypia were evaluated. The extreme diversity in morphologic features seen in histologic sections was reflected in the smears of PA. Metaplastic changes were observed more frequently in sections, while nuclear changes like inclusions/grooves were more commonly seen in smears. Other morphological features like cylindromatous pattern, giant cells and crystalline deposits were observed with equal frequency in smears and sections. Cytohistologic agreement was present in 45 of the 50 cases (90%). In 5 cases diagnosed as pleomorphic adenoma on FNAC, the histology revealed 1 case each of schwannoma, perineurioma, ectomesenchymal chondromyxoid tumor of tongue, adenoid cystic carcinoma and mucoepidermoid carcinoma. FNAC is a fairly accurate pre-operative procedure for the diagnosis of PA. The cytopathologist needs to be aware of the cytologic variations in pleomorphic adenoma so as to avoid diagnostic errors. Diagn. Cytopathol. 2009. © 2008 Wiley-Liss, Inc. [source] Insulin resistance is a major determinant of liver stiffness in nondiabetic patients with HCV genotype 1 chronic hepatitisALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2009S. PETTA Summary Background, In patients with chronic hepatitis C (CHC), liver stiffness measurement (LSM) by transient elastography (TE), is closely related to the stage of fibrosis, but may be affected by necroinflammation. Other factors, such as insulin resistance (IR), might influence the performance of LSM. Aims, To evaluate in a cohort of nondiabetic patients with genotype 1 CHC, whether IR and other anthropometric, biochemical, metabolic and histological factors contribute to LSM and to identify the best cut-off values of LSM for predicting different stages of fibrosis. Methods, Nondiabetic patients with genotype 1 CHC (n = 156) were evaluated by liver biopsy (Metavir score), anthropometric, biochemical and metabolic features including IR. Furthermore, all subjects underwent LSM by TE. Results, Severe fibrosis (F3,F4) was associated with LSM (OR 1.291; 95%CI 1.106,1.508). LSM was also independently correlated with low platelets (P = 0.03), high ,GT (P < 0.001) and high HOMA (P = 0.004) levels. A stiffness value ,8 KPa was identified as the best cut-off for predicting severe fibrosis (AUC 0.870); yet this cut-off still failed to rule out F3,F4 fibrosis in 22.7% of patients (false-negative rate) or rule in F3,F4 in 19.6% (false-positive rate). Platelets <200 × 103/mmc and a HOMA of >2.7 were the major determinants of these diagnostic errors in predicting severe fibrosis. Conclusions, In nondiabetic patients with genotype 1 CHC, insulin resistance, ,GT and platelet levels contribute to LSM independently of liver fibrosis. The identification of these three factors contributes to a more correct interpretation of LSM. [source] Prenatal diagnosis of 21-hydroxylase deficiency caused by gene conversion and rearrangements: pitfalls and molecular diagnostic solutionsPRENATAL DIAGNOSIS, Issue 13 2002Rong Mao Abstract Objectives The present paper reports the prenatal diagnosis of congenital adrenal hyperplasia (CAH) in two cases of 21-hydroxylase deficiency. DNA diagnostic errors can be caused by the presence of the highly homologous 21-hydroxylase pseudogene, CYP21P, adjacent to the functional gene, CYP21. The present paper details how complex gene conversions and rearrangements between the CYP21 and CYP21P pose unique complications for prenatal diagnosis. Methods Analysis of eight common mutations in the 21-hydroxylase gene as well as deletion of the entire gene is accomplished using polymerase chin reaction (PCR) followed by amplified created restriction site (ACRS) or allele-specific oligohybridization (ASO) and Southern blot followed by hybridization to a CYP21-specific probe. Linkage analysis was performed using microsatellite markers flanking the CYP21 gene. Results The direct mutation detection assay indicated a complicated gene conversion and rearrangement in the probands of both families. Interpretation of these rearrangements made it difficult to determine whether or not the fetuses would be affected with CAH. Linkage studies revealed that each fetus had inherited both parental disease chromosomes and was therefore predicted to be affected with CAH. Conclusion As observed in the two reported cases, direct DNA analysis may provide limited information due to gene conversion or rearrangement between the CYP21 and CYP21P genes. These cases suggest that direct mutation detection should be supported by linkage analysis, whenever possible, to provide more comprehensive information for the family. Copyright © 2002 John Wiley & Sons, Ltd. [source] Breast pathology guideline implementation in low- and middle-income countries,CANCER, Issue S8 2008Shahla Masood MD Abstract The quality of breast healthcare delivery and the ultimate clinical outcome for patients with breast cancer are directly related to the quality of breast pathology practices within the healthcare system. The Breast Health Global Initiative (BHGI) held its third Global Summit in Budapest, Hungary from October 1 to 4, 2007, bringing together internationally recognized experts to address the implementation of breast healthcare guidelines for the early detection, diagnosis, and treatment in low-income and middle-income countries (LMCs). From this group, a subgroup of experts met to address the specific needs and concerns related to breast pathology program implementation in LMCs. Specific recommendations were made by the group and process indicators identified in the areas of personnel and training, cytology and histopathology interpretation, accuracy of pathology interpretation, pathology reporting, tumor staging, causes of diagnostic errors, use of immunohistochemical markers, and special requirements to facilitate breast conservation therapy. The group agreed that the financial burden of establishing and maintaining breast pathology services is counterbalanced by the cost savings from decreased adverse effects and excessive use of treatment resources that result from incorrect or incomplete pathologic diagnosis. Proper training in breast pathology for pathologists and laboratory technicians is critical and provides the underpinnings of programmatic success for any country at any level of economic wealth. Cancer 2008;113(8 suppl):2297,304. © 2008 American Cancer Society. [source] | ||||||||||