SEARCH · PubMed Health

Results for “CLASSIFICATION”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

PubMed2006

Validating a newly proposed classification system for thoracolumbar spine trauma: looking to the future of the thoracolumbar injury classification and severity score.

BACKGROUND: Although numerous systems have been proposed, there is no universally accepted classification or scoring system for thoracolumbar spine injuries. Some have gained popularity, but most systems have never been modified or advanced beyond their initial introductory state. To the authors' knowledge, no thoracolumbar classification system has ever been validated in a systematic and scientific manner. STUDY PURPOSE: To critically review previous thoracolumbar classification systems, to discuss the proposal of the new Thoracolumbar Injury Classification and Severity Score (TLICS), to review the steps taken thus far in assessing the reliability of this system, and to discuss plans for future clinical validation of TLICS. METHODS: The authors performed a comprehensive search and analysis of previously published systems for classifying or scoring thoracolumbar spine injuries. Based on the merits and faults of these systems, among other factors, they have developed TLICS. CONCLUSIONS: Of the three phases of validating a fracture classification system described by Audige et al, TLICS has successfully passed through phase 1 (development) and phase 2 (multicenter agreement studies). With modifications made in response to phase 2 studies, TLICS will be ready to enter into the clinical validation phase. Although TLICS will initially be assessed for its ability to predict type of treatment, it is the authors' hope that, with appropriate analysis, the system will also be predictive of injury severity and clinical outcomes. These qualities remain to be demonstrated through rigorous prospective clinical investigation.

Humans↗

PubMed1999

Classification of the epilepsies: time for a change? A critical review of the International Classification of the Epilepsies and Epileptic Syndromes (ICEES) and its usefulness in clinical practice and epidemiological studies of epilepsy.

The Commission on Classification and Terminology of the International League against Epilepsy (ILAE) first devised a comprehensive classification for the epilepsies and epileptic syndromes nearly 30 years ago. Despite subsequent revisions, the classification remains too complicated to be of utility in clinical practice and epidemiological research. Recent developments in neuro-imaging and neurogenetics have also contributed to the limited usefulness of the current International Classification of the Epilepsies and Epileptic Syndromes (ICEES). This review examines the evolution, advantages, and notable disadvantages of the ICEES and assesses its previous application in several population-based studies of epilepsy. The important need for a new, simplified, and aetiologically orientated classification which is amenable to use outside of the tertiary epilepsy centre is discussed.

Epidemiologic Methods↗

PubMed2005

A validation study of a pain classification system for advanced cancer patients using content experts: the Edmonton Classification System for Cancer Pain.

The purpose of this study was to gather construct validity evidence for a pain classification system for advanced cancer patients using content experts. Two expert panels, representing regional (Panel A, n = 18) and national/international (Panel B, n = 52) palliative medicine and pain specialists, were purposefully selected to participate in a modified Delphi survey technique, to evaluate an existing pain classification system, the Revised Edmonton Staging System (rESS). Each panel participated in two survey rounds, with response rates of 67% (Panel A, Round 1), 39% (Panel A, Round 2), 56% (Panel B, Round 1) and 64% (Panel B, Round 2). The rESS consists of five features: mechanism of pain, incidental pain, psychological distress, addictive behavior and cognitive function. Most participants either agreed or strongly agreed with including the five existing rESS features in a pain classification system, ranging from 67% (Panel A, cognitive function) to 100% (Panel B, mechanism of pain). Most participants suggested keeping the current definitions for these features, with some revisions. Based on participant feedback, definitions for incidental pain, psychological distress, addictive behavior and cognitive function were revised, including the development of guidelines for use. To reflect its intended use as a classification system, the name of the instrument was changed to the Edmonton Classification System for Cancer Pain (ECS-CP).

Humans↗

PubMed1977

[Comparison of descriptive expressions between ILO U/C international classification of radiographs of pneumoconiosis 1971 and Japanese classification of pneumoconiosis law in Japan 1960 in pulmonary asbestosis (author's transl)].

In the explanatory text of the ILO U/C International classification of Radiographs of Pneumoconiosis (1971) sent to Japan in 1973, items of its expression on pulmonary asbestosis were analyzed by the author. On the other hand, items of Japanese Asbestosis Classification of Pneumoconiosis Law were also analyzed. The ILO U/C International Classification of Radiographs of Pneumoconiosis (1971) have some confused words. As to pulmonary asbestosis, an expression of irregular opacities is used, but the fundamental X-ray opacities such as linear opacities are forgot in the description. The X-ray findings of the pulmonary asbestosis are divided into 3 types as s, t and u. It is, however, difficult in practice to divide X-ray findings of the pulmonary asbestosis into such types. The classification of X-ray findings of the pulmonary asbestosis in the Japanese Pneumoconiosis Law is based on the classification worked out by many investigators i; the past, providing for simplicity and ease of handling.

Aged↗

PubMed1983

[Histological classification of oral leukoplakia by a classification number].

From 1969 to 1980 the authors examined 587 histological specimens of oral leukoplakia obtained from 424 patients. The histological findings were assessed in classification numbers qualitatively and quantitatively characterizing the subepithelial inflammation, epithelial hyperplasia, keratosis, the grade of epithelial dysplasia an the degree of infiltration when carcinoma had already developed. From this histological classification a classification number resulted which allows conclusions on the prognosis of the leukoplakia under study. Besides the grade of dysplasia also the features of the subepithelial inflammation are important for the prognostic assessment of leukoplakia. The classification numbers are suitable for data processing. In the grading system reported, the most important morphological findings are represented with qualitative and quantitative objectiveness. The classification number leads to more reliable comparison and evaluation of the results obtained by different research groups.

Female↗

PubMedDate not supplied

Comparison of lateral pillar classification and Catterall classification of Legg-Calvé-Perthes' disease.

To compare the predictive value of the Herring lateral pillar and the Catterall classifications of Legg-Calvé-Perthes' disease, 71 hips with radiographic follow-up to maturity were reviewed. The Herring classification was a significantly better predictor of Stulberg outcome than the Catterall classification. Three independent observers classified early fragmentation stage films by both Herring and Catterall classifications. The interobserver reliability of the Herring classification was significantly better than the reliability of the Catterall measure.

Hip Joint↗

PubMed1994

Agreement among and within groups of pathologists in the classification of rhabdomyosarcoma and related childhood sarcomas. Report of an international study of four pathology classifications.

BACKGROUND: An International Pathology study was conducted to measure the agreement demonstrated among and within groups of pathologists involved in the categorization of childhood rhabdomyosarcoma according to four pathology classifications. Data concerning agreement and survival experience according to patho-new subtypes were used as a basis for selection of a proposed new pathologic classification. METHODS: A random sample of 800 eligible patients was chosen from the Intergroup Rhabdomyosarcoma Study II (IRS-II) and was reviewed by pathologists representing eight institutions. A 20% sample of the 800 patients was then reviewed by the pathologists to determine the level of agreement with their original classification. In each instance the patients were classified according to four pathology systems: the conventional system, the International Society for Pediatric Oncology system (SIOP), the National Cancer Institute (NCI) system, and the cytohistologic system. RESULTS: Among the groups of pathologists, the highest measure of agreement was a Kappa value of K = 0.451 for the conventional system, followed by K = 0.406 for the SIOP system, K = 0.384 for the NCI system, and K = 0.328 for the cytohistologic system. For reproducibility within the groups of pathologists, the highest measure of agreement was K = 0.605 for the conventional system, followed by K = 0.579 for the NCI system, K = 0.573 for the SIOP system, and K = 0.508 for the cytohistologic system. CONCLUSIONS: There was a general similarity between the agreement reached within the modified conventional, STOP, and NCI systems, with the modified conventional system having the highest Kappa values, and thus the highest measure of agreement, both among and within the groups of pathologists. Also, the subtypes of the conventional system demonstrated a highly significant relationship to survival time. Hence, based on criteria of reproducibilty and prognostic significance, the proposed classification will essentially be a modification of the conventional system with elements of the SIOP and NCI systems.

Adolescent↗

PubMed2006

[Current classification of precursor lesions of oral squamous cell carcinoma principles of the WHO classification 2005].

The WHO classification of oral tumours summarizes the precancerous squamous cell lesions under the term epithelial precursor lesions. For the first time three classification schemas that histologically categorize oral epithelial precursor lesions are used analogously. According to the WHO suggestion of 2005 the traditional schema of grading dysplasia as mild dysplasia, moderate dysplasia, severe dysplasia and carcinoma in situ continues to be used. In addition the concept of intraepithelial neoplasia is introduced as squamous intraepithelial neoplasia I-III. Squamous intraepithelial neoplasia III (SIN III) combines severe dysplasia and carcinoma in situ. The Ljubljana classification of squamous intraepithelial lesions was originally established to grade laryngeal epithelial precancerous lesions. The clear and succinct nomenclature and the simple clinical utility of the Ljubljana classification have also proven to be useful for oral epithelial precursor lesions: squamous cell (simple) hyperplasia; basal/parabasal cell hyperplasia (analogous to mild dysplasia and to SIN I); atypical hyperplasia (analogous to moderate-severe dysplasia and to SIN I-III and is also called risky epithelium); carcinoma in situ (analogous to WHO carcinoma in situ and to SIN III). Atypical hyperplasia (risky epithelium) and carcinoma in situ are defined as lesions requiring either total excision or close clinical monitoring.

Carcinoma in Situ↗

PubMed2005

Non-linear cancer classification using a modified radial basis function classification algorithm.

This paper proposes a modified radial basis function classification algorithm for non-linear cancer classification. In the algorithm, a modified simulated annealing method is developed and combined with the linear least square and gradient paradigms to optimize the structure of the radial basis function (RBF) classifier. The proposed algorithm can be adopted to perform non-linear cancer classification based on gene expression profiles and applied to two microarray data sets involving various human tumor classes: (1) Normal versus colon tumor; (2) acute myeloid leukemia (AML) versus acute lymphoblastic leukemia (ALL). Finally, accuracy and stability for the proposed algorithm are further demonstrated by comparing with the other cancer classification algorithms.

Acute Disease↗

PubMed2004

Multi-class tumor classification by discriminant partial least squares using microarray gene expression data and assessment of classification models.

High-throughput DNA microarray provides an effective approach to the monitoring of expression levels of thousands of genes in a sample simultaneously. One promising application of this technology is the molecular diagnostics of cancer, e.g. to distinguish normal tissue from tumor or to classify tumors into different types or subtypes. One problem arising from the use of microarray data is how to analyze the high-dimensional gene expression data, typically with thousands of variables (genes) and much fewer observations (samples). There is a need to develop reliable classification methods to make full use of microarray data and to evaluate accurately the predictive ability and reliability of such derived models. In this paper, discriminant partial least squares was used to classify the different types of human tumors using four microarray datasets and showed good prediction performance. Four different cross-validation procedures (leave-one-out versus leave-half-out; incomplete versus full) were used to evaluate the classification model. Our results indicate that discriminant partial least squares using leave-half-out cross-validation provides a more realistic estimate of the predictive ability of a classification model, which may be overestimated by some of the cross-validation procedures, and the information obtained from different cross-validation procedures can be used to evaluate the reliability of the classification model.

Algorithms↗

PubMed2006

Classification of idiopathic toe walking based on gait analysis: development and application of the ITW severity classification.

Idiopathic toe walking (ITW), considered abnormal after the age of 3 years, is a common complaint seen by medical professionals, especially orthopaedic surgeons and physiotherapists. A classification for idiopathic toe walking would be helpful to better understand the condition, delineate true idiopathic toe walkers from patients with other conditions, and allow for assignment of a severity gradation, thereby directing management of ITW. The purpose of this study was to describe idiopathic toe walking and develop a toe walking classification scheme in a large sample of children. Three primary criteria, presence of a first ankle rocker, presence of an early third ankle rocker, and predominant early ankle moment, were used to classify idiopathic toe walking into three severity groups: Type 1 mild; Type 2 moderate; and Type 3 severe. Supporting data, based on ankle range of motion, sagittal joint powers, knee kinematics, and EMG data were also analyzed. Prospectively collected gait analysis data of 133 children (266 feet) with idiopathic toe walking were analyzed. Subjects' age range was from 4.19 to 15.96 years with a mean age of 8.80 years. Pooling right and left foot data, 40 feet were classified as Type 1, 129 were classified as Type 2, and 90 were classified as Type 3. Seven feet were unclassifiable. Statistical analysis of continuous variables comprising the primary criteria showed that the toe walking severity classification was able to differentiate between three levels of toe walking severity. This classification allowed for the quantitative description of the idiopathic toe walking pattern as well as the delineation of three distinct types of ITW patients (mild, moderate, and severe).

Adolescent↗

PubMed2006

Direct classification of high-dimensional data in low-dimensional projected feature spaces--comparison of several classification methodologies.

Previously, we introduced a distance (similarity)-based mapping for the visualization of high-dimensional patterns and their relative relationships. The mapping preserves exactly the original distances from all points to any two reference patterns in a special two-dimensional coordinate system, the relative distance plane (RDP). We extend the RDP mapping's applicability from visualization to classification. Several of the classifiers use the RDP directly. These include the standard linear discriminant analysis (LDA), nearest neighbor classifiers, and a transvariation probabilities-based classification method that is natural in the RDP. Several reference directions can also be combined to create new coordinate systems in which arbitrary classifiers can be developed. We obtain increased confidence in the classification results by cycling through all possible reference pairs and computing a misclassification-based weighted accuracy. The classification results on several high-dimensional biomedical datasets are compared.

Algorithms↗

PubMed1982

A group study for the classification of anorectal anomalies in Japan with comments to the International Classification (1970).

A study group was formed to undertake further investigation of the problems involved in the classification of anorectal anomalies. At first, a registration form including standardized techniques for clinical and roentogenologic investigation was defined, and then 254 cases were collected and analyzed by referring these materials to the International Classification by the Melbourne group in 1970. Our analysis disclosed: (1) It is imperative to establish a registration form with footnotes describing standardized techniques for clinical and roentogenologic investigations; (2) The rectourethral fistula has been classified simply as high type under the present International Classification, but differences in the levels of the rectal pouch and of the point of fistula, as observed in the collected materials, tends to show that further subdivision of this anomaly may be indicated; (3) An abnormal skin fold at the anal and/or perineal sites is not always diagnostic of low type, specifically of covered anus-complete. Conversely, some infants with high type anomaly had abnormal skin folds; and (4) Two types of anomaly, which have not been well described in the present classification, were detected. They were "rectal membraneous atresia" and "recto-penile fistula."

Anal Canal↗

PubMed2002

Fundamental classification of perinatal death. Validation of a new classification system of perinatal death.

OBJECTIVE: To validate a newly introduced classification system for the registration of perinatal mortality. DESIGN: Descriptive. SETTING: Dutch Healthcare region Delft-Westland-Oostland (DWO). MATERIAL AND METHODS: In a 10-years period (1983-1992), all cases of perinatal death with a birthweight above 500 g (n=239) were included into the study. Six assessors: four gynaecologists and two paediatricians were asked to classify all cases using a classification model proposed by the authors. This model is based on the underlying cause of death using simple principles of obstetrical and neonatal pathology: birth trauma, infection, placenta or cord pathology, pathology of immune tolerance of mother and fetus, congenital malformation of the fetus and complications of a pre-viable delivery. Therefore, we used the term fundamental classification. The six assessors worked independently of each other in classifying all cases of perinatal death, were not involved in the original development of the system and were unaware of the results of the classification of their colleagues. Agreement beyond chance between assessors was calculated using kappa's coefficient for multiple observers and multiple test results. RESULTS: Overall kappa was 0.70 (95% confidence interval (C.I.) 0.68-0.72). Reproducibility was poor for the categories trauma and unclassifiable, fair for the categories infections and placental/cord pathology, and very good to excellent for the categories maternal immune system pathology, congenital malformations and complications of prematurity. CONCLUSIONS: The proposed system showed a good level of agreement and appeared to be simply applicable. It offers a good insight in the underlying cause of death with the possibility for recognising preventive factors in future pregnancies and will enable (inter)national comparisons in causes of perinatal death. A reliable uniform registration of perinatal death based on the underlying causes should be the basis for improvement of the quality of perinatal care.

Birth Injuries↗

PubMed1997

[Histological classification of renal cell carcinoma--problems in JUA classification].

BACKGROUND: Although renal cell carcinoma (RCC) is often heterogeneous, the histological classification of RCC in Japanese Urological Association (JUA) is designed to select only the dominant histological components. We evaluated whether this system could provide an adequate information concerning the prognosis of the patients. METHODS: Histological slides of 130 cases with RCC were microscopically evaluated. We classified these cases according to the JUA classification, and also checked the presence or absence of each histological components (3 cell types and 5 histological architectures) regardless of whether or not they were dominant. Univariate and multivariate analysis were then performed to determine the histological components which have prognostic impact on patient survival. RESULTS: Multivariate analysis demonstrated that only spinde/pleomorphic cells and solid architecture were the significant prognostic parameters. The presence of these histological components was not correctly shown in the JUA classification. CONCLUSION: The histological classification of RCC in JUA did not provide enough information about the presence of the important prognostic parameters. This system should be modified to describe all the histological components regardless of whether they are dominant or not.

Adult↗

PubMed2001

[Clinical significance of WHO classification and MDS 2000 classification in myelodysplastic syndromes].

Excluding chronic myelomonocytic leukemia, a total of 92 consecutive patients with myelodysplastic syndrome showing less than 20% blasts in the bone marrow were analyzed. We evaluated the clinical significance of the WHO and MDS 2000 classifications by reviewing each MDS patient according to the classification. The WHO criteria classified the MDS patients into 36 with RA, 22 with RCMD and 33 with RAEB, whereas according to the MDS 2000 criteria there were 19 RAEB-I patients and 15 RAEB-II patients. Based on the WHO classification, the RCMD patients had higher platelet counts and percentages of blasts among BM cells than the RA patients (P = 0.0018, P = 0.0001). Twenty percent of the RA patients, 44.8% of the RCMD patients, and 70.8% of the RAEB patients had cytogenetic abnormalities. Among them, the poor karyotype was present in 6.7% of the RA patients, 21.0% of the RCMD patients and 41.6% of the RAEB patients. The rate of acute leukemia death was 14.3% in the RA patients, 67.7% in the RAEB patients and 50.0% in the RCMD patients. Analysis of survival times revealed significant differences between RA and RCMD patients (P = 0.0482). The clinical features of RCMD patients were intermediate between those of RAEB and RA patients. There was no difference between the clinical features of the RAEB-I and RAEB-II patients in the MDS 2000 classification.

Aged↗

PubMed1992

Classification of accidents in the Arctic. A suggestion for adaptation of the Nordic classification for accident monitoring.

Since 1980 the Nordic Medico-Statistical Committee (NOMESCO) has supported the development of the Classification for Accident Monitoring. The objective of the Classification is to provide the foundation for accident prevention. In agreement with the purpose of NOMESCO to establish comparable medical statistics in the Nordic countries, it is considered how the Nordic Classification might be adapted to conditions in Arctic areas, in order also to facilitate accident prevention in these areas. The Classification is multiaxial and describes place of occurrence, injury mechanism, activity (of victim), products involved in accidents, and information of special relevance to traffic accidents and occupational accidents. The hierarchical build-up of the coding system allows subspecification of the variables mentioned above, thus enabling the system to contain such information which is suggested for Arctic areas, and at the same time preserving the comparability of data at an aggregated level. Further development is suggested in a plan of work.

Accidents↗

PubMed2004

Categorizing patients with occupational low back pain by use of the Quebec Task Force Classification system versus pain pattern classification procedures: discriminant and predictive validity.

BACKGROUND AND PURPOSE: Quebec Task Force Classification (QTFC) and pain pattern classification (PPC) procedures, including centralization and noncentralization, are common classification procedures. Classification was done to estimate validity of data obtained with QTFC and PPC procedures for differentiating patient subgroups at intake and for use in predicting rehabilitation outcomes at discharge and work status at 1 year after discharge from rehabilitation. SUBJECTS: Patients (n=171, 54% male; mean age=37 years, SD=10, range=18-62) with acute work-related low back pain referred for physical therapy were analyzed. METHODS: Patients completed pain and psychosocial questionnaires at initial examination and discharge and pain diagrams throughout intervention. Physical therapists classified patients using QTFC and PPC data at intake. Patients were classified again at discharge by PPC (time-dependent PPC). RESULTS: Analysis of variance of showed QTFC and PPC data could be used to differentiate patients by pain intensity or disability at intake. Analysis of covariance showed that intake PPC predicted pain intensity and disability at discharge, but QTFC did not. Logistic regression showed that PPC predicted work status at 1 year, but QTFC did not. Classifying patients over time using time-dependent PPC data reduced the false positive rate by 31% and increased percentage of change in pretest-posttest probability of return to work by 16% compared with classifying patients at intake. DISCUSSION AND CONCLUSION: Results support the discriminant validity of the QTFC data at intake and predictive validity of the PPC data at intake. Tracking PPC over time increases predictive validity for 1-year work status.

Acute Disease↗