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PubMedDate not supplied

An independent assessment of two clubfoot-classification systems.

We conducted an independent assessment of two clubfoot-classification systems. In a blinded trial, two orthopaedists scored 55 feet by using the classification systems developed by Pirani et al. and by Dimeglio et al. Thirty-seven of the feet were also scored by a physical therapist. By using the 10-point classification described by Pirani, the two physician examiners tallied total scores that were within one point of one another 89% of the time. The mean difference between the scores assigned by the two examiners was 0.6 points. For the 20-point classification described by Dimeglio et al., total scores tallied by the two physician examiners were within two points of one another 91% of the time. The mean difference between the scores assigned by the two physician examiners was 1.4 points. Correlation coefficients were 0.90 (p = 0.0001) for the Pirani classification, and 0.83 (p = 0.0001) for the Dimeglio classification. Correlation coefficients were much lower for the first 15 feet scored and were also lower when the therapist's scores were included. Overall, both classification systems had very good interobserver reliability after the initial learning phase.

Clubfoot↗

PubMed1998

Accuracy of racial classification of Vietnamese patients in a population-based cancer registry.

Racial classification of Asian subgroups is increasingly important for health statistics, given the growing Asian-American populations. This study reports the reliability of racial classification of Vietnamese in population-based cancer registry data from northern California. From the Greater Bay Area Cancer Registry, we selected 2240 persons diagnosed with cancer in 1989-1992 and whom the registry considered Vietnamese by birthplace and/or registry race and/or surname, or who were Southeast Asian or Chinese by race. One thousand ninety persons (49%) were interviewed. Sensitivity and predictive value positive, and cancer incidence rates, were calculated using different combinations of the classification factors (birthplace, registry race, and name). By registry-reported race alone, 74% of those the registry classified as Vietnamese agreed with this classification on interview, while 90% of those identifying themselves as Vietnamese were so classified. With classification based on 2 of 3 factors, 78% of those classified as Vietnamese agreed, and 91% of self-reported Vietnamese were correctly classified. Misclassification was associated with age, sex, year of immigration, education, and language use. Registry-based annual age-adjusted all-site cancer incidence rates per 100,000 for Vietnamese were 287.7 for males and 221.3 for females. Rates adjusted for self-reported ethnicity were 242.8 (male) and 213.7 (female). Registry classification of Vietnamese is currently problematic. Approximately 20% of cancer cases classified as Vietnamese are probably not Vietnamese. The higher incidence rates for Vietnamese in the United States than in Vietnam partly may reflect such classification error.

Adult↗

PubMed1998

[Ishikawa's classification of cavernous sinus lesions by clinico-anatomical findings].

Jefferson's classification (1938) has been used to localize lesions of the cavernous sinus. However, we think this classification is sometimes incorrect in identifying localization based on clinico-anatomical evidence. We investigated the efficacy of the newly proposed Ishikawa's classification. Based on the analysis on serial sections of human cavernous sinus, it classifies the locus of the lesion into three groups: anterior, middle, and posterior, corresponding to the location of the intracranial orifice of the optic canal and of the penetration of the maxillary nerve into the cavernous sinus. The subjects were 162 cases with cavernous sinus lesions. They were classified by the two methods. There was a total of 111 cases (69%) of unclassified cases in Jefferson's classification and 45 (28%) in Ishikawa's classification. The anterior type was frequently encountered in cases caused by inflammations and both posterior and whole types were caused by tumors in Ishikawa's classification. It was concluded that Ishikawa's classification is clinically useful to identify and classify the localization of cavernous sinus lesions.

Aneurysm↗

PubMed1998

[Clinical evaluation of classifications of malignant lymphoma from the viewpoint of history].

The classification of malignant lymphoma has been modified several times in this century and has often been a source of confusion for clinical oncologists. This review deals with the historical aspects of lymphoma classifications from the viewpoint of clinical relevance. Until recently, in the United States and Japan, a Working Formulation (WF) has been used as the main classification system for malignant lymphoma. WF was predominantly based on hematoxilin/eosins morphology, grouping the lymphoma subtypes according to their overall survival. Since WF was proposed in 1982, the development of immunophenotypic and molecular genetic analyses has enabled us to identify several previously unrecognized disease entities with distinct histopathological and clinical features. In 1994, based on such development, the International Lymphoma Study Group proposed a new classification, the Revised European-American Classification (REAL Classification). The clinical relevance of the REAL Classification is discussed based on recent clinicopathologic studies.

History, 20th Century↗

PubMed1998

[TNM classification for urological cancer].

The 5th edition of the new TNM classification for urological cancer has been published by UICC in 1997. Herein, the classification of 4 urological carcinomas (kidney, urinary bladder, renal pelvis and ureter, and urethra) is presented and discussed in comparison with the latest revisions in 1987 and 1992. In the 5th edition, the main revised points are as follows: As for kidney, the primary tumor cut off between T1 and T2 was changed from 2.5 cm to 7.0 cm, and the N classification was simplified as for urinary bladder, all muscle invasive tumors (T2 or T3a in the 1992 classification) are included in the T2 category, which is then subdivided into T2a and T2b; in the urethra, new T categories on transitional cell carcinoma of the prostate and prostatic urethra have been added, and the N classification is simplified; there is no change in the classification for the renal pelvis and ureter. According to these changes, a new system of stage grouping is proposed. There may still be widespread disagreement over the appropriateness of some of the changes introduced in the 5th edition of 1997. It is essential to continue efforts to improve the accuracy of determining the clinical extent of malignant tumors, and to work together in order to achieve our objectives for a unified system of TNM classification.

Female↗

PubMed1999

World Health Organization classification of neoplastic diseases of the hematopoietic and lymphoid tissues. A progress report.

The World Health Organization (WHO) classification has been developed under the joint auspices of the European Association for Hematopathology (EAHP) and the Society for Hematopathology (SH). First organized in 1995, the Steering Committee appointed 10 committees for T-cell and B-cell lymphomas and leukemias and myeloid and histiocytic tumors to develop a relevant list of diseases and establish definitions of each disease according to established criteria. The WHO classification uses the principles of the Revised European American Classification of Lymphoid Neoplasms (REAL), which defines each disease according to its morphologic features, immunophenotype, genetic features, postulated normal counterpart, and clinical features. The proposed classification was presented at the United States-Canadian Academy of Pathology meeting in 1997. The Steering Committee also appointed a Clinical Advisory Committee to ensure that the classification meets clinical needs and to resolve questions of clinical significance. The proposed WHO classification for lymphomas is similar to the REAL classification for lymphomas, with minor modifications and reassessment of provisional categories based on new data since 1994.

Hematologic Neoplasms↗

PubMed2006

Selection of reference films based on reliability assessment of a classification of high-resolution computed tomography for pneumoconioses.

OBJECTIVE: Worldwide demand has increased for the development of a computed tomography (CT) classification system that supplements the ILO classification of radiographs for pneumoconioses. The authors aimed to show preliminary reliability test results for selected referent films for the CT classification system developed through an international effort by researchers from seven countries. METHODS: Reading trials by eight physicians who have considerable experience in pneumoconioses using a total of 114 lung zones consisting of 6 lung zones of 19 CT films of dust-exposed workers were performed to assess reliability of the classification system by weighted kappa. The results were also utilized for selecting reference films. RESULTS: A good agreement was observed for both first and second reading trials for rounded opacities (weighted kappa=0.76, 0.74, first and second trial results, respectively), irregular opacities (0.60, 0.48), emphysema (0.56, 0.70) and honeycombing (0.72, 0.79). Ground glass opacities, on the other hand, showed moderate agreement (0.43, 0.38). Intra-reader agreements among eight readers were shown in the same table as the mean and standard deviation of weighted kappa statistics. The inter-reader agreement for pleural thickening was not as good as for parenchymal lesions. DISCUSSION: The CT classification development may pioneer noble and sensitive medical screening for dust-exposed workers in selected settings. This system may be applied to radiographic borderline cases of profusion 0/1 and 1/0 by the ILO classification, in a setting that assures the occupational safety and health of workers exposed to some newly developed chemical compounds.

Classification↗

PubMed2003

Prevalence of rheumatoid arthritis in persons 60 years of age and older in the United States: effect of different methods of case classification.

OBJECTIVE: To determine prevalence estimates for rheumatoid arthritis (RA) in noninstitutionalized older adults in the US. Prevalence estimates were compared using 3 different classification methods based on current classification criteria for RA. METHODS: Data from the Third National Health and Nutrition Examination Survey (NHANES-III) were used to generate prevalence estimates by 3 classification methods in persons 60 years of age and older (n = 5,302). Method 1 applied the "n of k" rule, such that subjects who met 3 of 6 of the American College of Rheumatology (ACR) 1987 criteria were classified as having RA (data from hand radiographs were not available). In method 2, the ACR classification tree algorithm was applied. For method 3, medication data were used to augment case identification via method 2. Population prevalence estimates and 95% confidence intervals (95% CIs) were determined using the 3 methods on data stratified by sex, race/ethnicity, age, and education. RESULTS: Overall prevalence estimates using the 3 classification methods were 2.03% (95% CI 1.30-2.76), 2.15% (95% CI 1.43-2.87), and 2.34% (95% CI 1.66-3.02), respectively. The prevalence of RA was generally greater in the following groups: women, Mexican Americans, respondents with less education, and respondents who were 70 years of age and older. CONCLUSION: The prevalence of RA in persons 60 years of age and older is approximately 2%, representing the proportion of the US elderly population who will most likely require medical intervention because of disease activity. Different classification methods yielded similar prevalence estimates, although detection of RA was enhanced by incorporation of data on use of prescription medications, an important consideration in large population surveys.

Aged↗

PubMed2006

Short-term prediction of mortality in patients with systemic lupus erythematosus: classification of outcomes using random forests.

OBJECTIVE: To identify demographic and clinical characteristics that classify patients with systemic lupus erythematosus (SLE) at risk for in-hospital mortality. METHODS: Patients hospitalized in California from 1996 to 2000 with a principal diagnosis of SLE (N = 3,839) were identified from a state hospitalization database. As candidate predictors of mortality, we used patient demographic characteristics; the presence or absence of 40 different clinical conditions listed among the discharge diagnoses; and 2 summary indexes derived from the discharge diagnoses, the Charlson Index and the SLE Comorbidity Index. Predictors of patients at increased risk of mortality were identified and validated using random forests, a statistical procedure that is a generalization of single classification trees. Random forests use bootstrapped samples of patients and randomly selected subsets of predictors to create individual classification trees, and this process is repeated to generate multiple trees (a forest). Classification is then done by majority vote across all trees. RESULTS: Of the 3,839 patients, 109 died during hospitalization. Selecting from all available predictors, the random forests had excellent predictive accuracy for classification of death. The mean classification error rate, averaged over 10 forests of 500 trees each, was 11.9%. The most important predictors were the Charlson Index, respiratory failure, SLE Comorbidity Index, age, sepsis, nephritis, and thrombocytopenia. CONCLUSION: Information on clinical diagnoses can be used to accurately predict mortality among hospitalized patients with SLE. Random forests represent a useful technique to identify the most important predictors from a larger (often much larger) number and to validate the classification.

Adult↗

PubMed2005

International Classification of Childhood Cancer, third edition.

BACKGROUND: The third edition of the International Classification of Diseases for Oncology (ICD-O-3), which was published in 2000, introduced major changes in coding and classification of neoplasms, notably for leukemias and lymphomas, which are important groups of cancer types that occur in childhood. This necessitated a third revision of the 1996 International Classification of Childhood Cancer (ICCC-3). METHODS: The tumor categories for the ICCC-3 were designed to respect several principles: agreement with current international standards, integration of the entities defined by newly developed diagnostic techniques, continuity with previous childhood classifications, and exhaustiveness. RESULTS: The ICCC-3 classifies tumors coded according to the ICD-O-3 into 12 main groups, which are split further into 47 subgroups. These 2 levels of the ICCC-3 allow standardized comparisons of the broad categories of childhood neoplasms in continuity with the previous classifications. The 16 most heterogeneous subgroups are broken down further into 2-11 divisions to allow study of important entities or homogeneous collections of tumors characterized at the cytogenetic or molecular level. Some divisions may be combined across the higher-level categories, such as the B-cell neoplasms within leukemias and lymphomas. CONCLUSIONS: The ICCC-3 respects currently existing international standards and was designed for use in international, population-based, epidemiological studies and cancer registries. The use of an international classification system is especially important in the field of pediatric oncology, in which the low frequency of cases requires rigorous procedures to ensure data comparability.

Brain Neoplasms↗

PubMed2005

[Urinary bladder tumours. The new 2004 WHO classification].

Increasing knowledge in molecular genetic research on urinary bladder carcinoma has allowed us to classify the morphological picture on the basis of a better understanding. But this new knowledge will only be ground-breaking if it can be correlated with the clinical outcome of urinary bladder tumours and with histopathological findings. The use of the new 2004 WHO classification results in a standardized diagnosis of urothelial tumours by means of an exact definition of the subgroups. In the future, trials can thus be compared worldwide and risk profiles can be stratified. Further research in molecular genetics and correlation with the current classification together with molecular biological techniques may allow refinement of this scheme, e.g. by immunohistochemical subclassifications, enabling identification of potentially genetically unstable tumours. In this paper we present the new 2004 WHO classification of urinary bladder tumours emphasizing the changes in relation to the former classifications focusing on histological typing, grading and molecular characterization. Until the new classification is finally validated, and those working in the field have become familiar with it, the WHO classification of 1973 should be mentioned additionally in the histopathological report.

Humans↗

PubMed2026

IASLC Update on Classification of Pulmonary Neuroendocrine Neoplasms.

Since the publication of the 2021 WHO classification of thoracic tumors, our knowledge of pulmonary neuroendocrine neoplasms (NENs) has expanded significantly, particularly through the elucidation of molecular pathways and proposals to refine histopathologic classification. This expanded knowledge across all aspects of pulmonary NENs holds promise for more precise stratification of neuroendocrine tumors (NETs) and the potential development of novel, subtype-specific therapeutic strategies for all NENs. Based on our comprehensive review of the current pulmonary NEN landscape, our multidisciplinary expert panel has deliberated on the modification and updating of the 2021 classification, resulting in the proposal of a new pulmonary carcinoid/NET classification presented in this position paper, which incorporates the following three major points: (1) The proposed framework continues the shift from the traditional carcinoid terminology toward broader adoption of the "NET" nomenclature as found in other organ systems while retaining the term "carcinoid" as the primary diagnostic term to ensure clear communication with thoracic clinical providers. (2) Ki-67 has been incorporated as a diagnostic criterion, aligning with practices in other NET classifications. (3) There is formal recognition of the concept of "carcinoid/NET G3," a rare subset of lung carcinoids characterized by increased proliferative activity but with molecular features more aligned with pulmonary NETs than with high-grade neuroendocrine carcinomas. This position paper on the current knowledge of pulmonary NENs, including the proposed carcinoid/NET classification, will aid in accurate tumor categorization and guide treatment strategies.

Carcinoid tumor↗

PubMed1997

[Coronary perfusion: a classification based on the type and relative extension of coronary irrigation (II). An angiographic algorithm].

INTRODUCTION AND OBJECTIVES: An angiographic algorithm of clinical utility, applicable to conventional coronariography, is proposed to establish different patterns of coronary distribution depending on the characteristics of the myocardial perfusion, considering the starting point as the segmentary classification of the arterial irrigation of the left ventricle. METHODS: To validate this system of classification, 30 hearts coming from necropsy were studied, through anatomical and angiographical analysis. The average age of the population studied was of 69.8 +/- 14.6 years. The range was between 26 and 91 years. To study them, the hearts were unrolled and after a coronariography and a dissection of the coronary arterial tree, the identification of the perfusion mode--exclusive or shared--of every left ventricle segment was done. Then an algorithm based on the type of division of the left main branch, and on the type of perfusion of the left ventricle inferobasal segment was applied to the angiographic frames. There was statistical analysis of the data obtained in the anatomic and angiographic studies. To verify the applicability of the algorithm, it was employed to successive series of 100 coronariographies in vivo, and these were then compared to the results obtained with the necropsy series. RESULTS: The statistical comparison between the percentages of the classification obtained from both analyses of the necropsy series showed no significant differences. The statistical comparison of the percentages of the classification obtained between the in vivo and post-mortem analyses did not show any significant difference either. CONCLUSIONS: The angiographical algorithm developed allows to classify the myocardial perfusion of the left ventricle, by the conventional coronary arteriography, in three groups of clinical interest. The classification is based on the predominance of the left ventricular segments exclusively irrigated by: the anterior interventricular artery (type I), the circumflex artery (type II), or a balance between both arteries (type III). The angiographic projections in left anterior oblique with caudal angulation and right anterior oblique are important for its application. The classification of the ventricular perfusion established with the developed algorithm can be validated as being equivalent to the one obtained through the anatomical series.

Adult↗

PubMed2006

Classification of headache disorders.

Clinical diagnostic classifications are critical when clear biological markers are not available. Such is the case in many headache disorders and mental disorders. Also, it is crucial that the classification is widely accepted and utilized. A main goal of classification is to be a universal language for categorizing a disease or a set of disorders, establishing diagnostic criteria, and promoting unity in treatment. The International Headache Society published its first Classification of Headache Disorders in 1988 and its second edition in 2004. The first classification paved the way for a better understanding of the epidemiology, mechanisms, and treatment of headache disorders, and the second edition likely will magnify our knowledge. This article provides an overview of the classification system and outlines some of the major changes in the revised edition.

Diagnosis, Differential↗

PubMed1999

HICLAS: a taxonomic database system for displaying and comparing biological classification and phylogenetic trees.

MOTIVATION: Numerous database management systems have been developed for processing various taxonomic data bases on biological classification or phylogenetic information. In this paper, we present an integrated system to deal with interacting classifications and phylogenies concerning particular taxonomic groups. RESULTS: An information-theoretic view (taxon view) has been applied to capture taxonomic concepts as taxonomic data entities. A data model which is suitable for supporting semantically interacting dynamic views of hierarchic classifications and a query method for interacting classifications have been developed. The concept of taxonomic view and the data model can also be expanded to carry phylogenetic information in phylogenetic trees. We have designed a prototype taxonomic database system called HICLAS (HIerarchical CLAssification System) based on the concept of taxon view, and the data models and query methods have been designed and implemented. This system can be effectively used in the taxonomic revisionary process, especially when databases are being constructed by specialists in particular groups, and the system can be used to compare classifications and phylogenetic trees. AVAILABILITY: Freely available at the WWW URL: http://aims.cps.msu.edu/hiclas/ CONTACT: pramanik@cps.msu.edu; lotus@wipm.whcnc.ac.cn

Classification↗

PubMed2026

A module-based approach for post-omics, post-GWAS network-based gene classification.

MOTIVATION: Complex traits and diseases are highly polygenic and understanding the full set of genes involved is a central challenge in biomedicine. However, due to sample size limitations and noise (technical and biological), experimental approaches for disease-gene discovery such as transcriptomics and GWAS result in long, noisy, heterogeneous gene lists, which may be trimmed to a subset of likely relevant genes while leaving several false negatives. Computational gene classification approaches, especially those using genome-scale molecular interaction networks, are promising avenues for complementing such experimental findings by analytically expanding observed gene lists based on the functional relatedness between genes. We previously introduced the network-based gene classification approach, GenePlexus, which was rigorously benchmarked to show state-of-the-art performance, especially for predicting novel genes associated with biological processes and fine-grained phenotypes. Network-based gene classification performance,however, declines for diseases, especially when the inputs are omics and GWAS-based long gene lists. RESULTS: Here, we show that these disease gene lists span multiple biological processes spread across the molecular network, and we propose ModGenePlexus, a new network-based gene classification method that takes a two-stage approach. First, clustering and semi-supervised learning decomposes the input gene list into coherent, denoised network gene modules. Then, ModGenePlexus trains supervised (GenePlexus) classifiers for each module and aggregates predictions to return genome-wide rankings. We benchmarked ModGenePlexus across simulated data, transcriptomic signatures, and GWAS datasets (together spanning hundreds of diseases), showing improved recovery of known disease genes compared to GenePlexus. Beyond improved classification, the results of enrichment analysis of ModGenePlexus outputs are much more interpretable by virtue of revealing nuanced biological processes. Together, these results establish ModGenePlexus as a scalable, interpretable tool for gene classification of GWAS- and omics-derived gene lists across diverse biological contexts. AVAILABILITY AND IMPLEMENTATION: ModGenePlexus is freely available on GitHub at https://github.com/krishnanlab/ModGenePlexus, and the full source code and results supporting this study are available on Zenodo at https://zenodo.org/records/19857910.

Genome-Wide Association Study↗

PubMed2005

Classification of stillbirth by relevant condition at death (ReCoDe): population based cohort study.

OBJECTIVE: To develop and test a new classification system for stillbirths to help improve understanding of the main causes and conditions associated with fetal death. DESIGN: Population based cohort study. SETTING: West Midlands region. SUBJECTS: 2625 stillbirths from 1997 to 2003. MAIN OUTCOME MEASURES: Categories of death according to conventional classification methods and a newly developed system (ReCoDe, relevant condition at death). RESULTS: By the conventional Wigglesworth classification, 66.2% of the stillbirths (1738 of 2625) were unexplained. The median gestational age of the unexplained group was 237 days, significantly higher than the stillbirths in the other categories (210 days; P < 0.001). The proportion of stillbirths that were unexplained was high regardless of whether a postmortem examination had been carried out or not (67% and 65%; P = 0.3). By the ReCoDe classification, the most common condition was fetal growth restriction (43.0%), and only 15.2% of stillbirths remained unexplained. ReCoDe identified 57.7% of the Wigglesworth unexplained stillbirths as growth restricted. The size of the category for intrapartum asphyxia was reduced from 11.7% (Wigglesworth) to 3.4% (ReCoDe). CONCLUSION: The new ReCoDe classification system reduces the predominance of stillbirths currently categorised as unexplained. Fetal growth restriction is a common antecedent of stillbirth, but its high prevalence is hidden by current classification systems. This finding has profound implications for maternity services, and raises the question whether some hitherto "unexplained" stillbirths may be avoidable.

Birth Weight↗

PubMed2006

Classification images with uncertainty.

Classification image and other similar noise-driven linear methods have found increasingly wider applications in revealing psychophysical receptive field structures or perceptual templates. These techniques are relatively easy to deploy, and the results are simple to interpret. However, being a linear technique, the utility of the classification-image method is believed to be limited. Uncertainty about the target stimuli on the part of an observer will result in a classification image that is the superposition of all possible templates for all the possible signals. In the context of a well-established uncertainty model, which pools the outputs of a large set of linear frontends with a max operator, we show analytically, in simulations, and with human experiments that the effect of intrinsic uncertainty can be limited or even eliminated by presenting a signal at a relatively high contrast in a classification-image experiment. We further argue that the subimages from different stimulus-response categories should not be combined, as is conventionally done. We show that when the signal contrast is high, the subimages from the error trials contain a clear high-contrast image that is negatively correlated with the perceptual template associated with the presented signal, relatively unaffected by uncertainty. The subimages also contain a "haze" that is of a much lower contrast and is positively correlated with the superposition of all the templates associated with the erroneous response. In the case of spatial uncertainty, we show that the spatial extent of the uncertainty can be estimated from the classification subimages. We link intrinsic uncertainty to invariance and suggest that this signal-clamped classification-image method will find general applications in uncovering the underlying representations of high-level neural and psychophysical mechanisms.

Adult↗