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PubMed2005

[About job classifications].

BACKGROUND: In the various existing information systems, the work-related variables (occupation, job position, and economic sector) are not always classified in the same manner. OBJECTIVES: To develop a classification of occupations and economic sectors that could be used for the majority of analyses of data on work-related morbidity and mortality. METHODS: The classification of occupations was created with the following criteria in mind: comparability with the currently used classification systems ISTAT (the National Institute of Statistics) 1971, 1981, 1991 and INAIL (the National Institute for Insurance Against Accidents & Diseases); a limited number of items, so as to ensure acceptable statistical power; maximum variance among groups and minimum variance within groups, in terms of the three dimensions of greatest interest for defining exhausting jobs. To this end, three groups of experts were consulted, one group of experts in the analysis of occupational differences in the occurrence of accidents and two groups of experts on occupational health. RESULTS: The three different sets of aggregates produced by the three groups of experts were combined into 56 items, referred to as the "Classification of occupations for the surveillance of differences in mortality and morbidity". CONCLUSIONS: The classification can be used in future analyses of occupational risks and injuries for the comparison of different information sources and time periods.

Humans↗
PubMed2005

[A preliminary study of angiographic classification and treatment of central arteriovenous malformations in jaws].

OBJECTIVE: To elaborate on the angiographic classification of central arteriovenous malformations (AVMs) in jaws, and to evaluate the correlation between this classification and treatment options. METHODS: X-ray films and angiograms of 25 cases with AVMs in the jaw were retrospectively reviewed to evaluate the appearance of radiolucency, feeding arteries, nidus of the malformations and draining veins. Based on the findings a classification of angioarchitecture was recommended. Furthermore, the treatment results of these cases were reviewed to assess the correlation between this classification and treatment options. RESULTS: The angiographic pictures of 25 cases with central AVMs could be divided into five types: type I (n = 5) was with merely diffused micro-arteriovenous fistulas (AVFs); type II (n = 8) demonstrated a large venous pouch, all the feeding arteries drained into it; type III (n = 7) had a large venous pouch together with diffused micro-AVFs (I + II); type IV (n = 2) had multiple venous pouches; type V (n = 3) had multiple venous pouches and diffused micro-AVFs (I + IV). The angioarchitecture corresponded well to the radiographic appearance in all except one case. With respect to the treatment, type II, III, IV AVMs gained clinical cure in 100% of cases, whereas type I and type V AVMs obtained clinical cure only in 3 of 5 and 1 of 3 cases respectively. CONCLUSIONS: Central AVMs in jaws exhibited variant patterns of angioarchitecture, which could be divided into five types. Elaboration of this classification was helpful for decision-making on choosing appropriate therapy.

Adolescent↗
PubMed1992

Proposed classification of complications of surgery with examples of utility in cholecystectomy.

Lack of uniform reporting of negative outcomes makes interpretation of surgical literature difficult. We attempt to define and classify negative outcomes by differentiating complications, sequelae, and failures. Complications and sequelae result from procedures, adding new problems to the underlying disease. However, complications are unexpected events not intrinsic to the procedure, whereas sequelae are inherent to the procedure. Failures are events in which the purpose of the procedure is not fulfilled. We propose a classification of complications based on four grades: Grade I complications are alterations from the ideal postoperative course, non-life-threatening, and with no lasting disability. Complications of this grade necessitate only bedside procedures and do not significantly extend hospital stay. Grade II complications are potentially life-threatening but without residual disability. Within grade II complications a subdivision is made according to the requirement for invasive procedures. Grade III complications are those with residual disability, including organ resection or persistence of life-threatening conditions. Finally, grade IV complications are deaths as a result of complications. To illustrate the relevance of the classification, we reviewed 650 cases of elective cholecystectomy. Risk factors for development of complications were determined, and the classification was also used to analyze the value of a modified APACHE II as a preoperative prognostic score. Both supported the relevance of the proposed classification. The advantages of such a classification are (1) increased uniformity in reporting results, (2) the ability to compare results of two distinct time periods in a single center, (3) the ability to compare results of surgery between different centers, (4) the ability to compare results of surgical versus nonsurgical measures, (5) the ability to perform adequate metaanalysis, (6) the ability to identify objective preoperative risk factors, and (7) the ability to establish preoperative prognostic scores.

Adult↗
PubMed2005

A soft decision algorithm for obstructive sleep apnea patient classification based on fast estimation of wavelet entropy of RRI data.

A soft decision algorithm for Obstructive Sleep Apnea (OSA) patient classification using R-R interval (RRI) data is investigated. This algorithm is based on fast and approximate estimation of the entropy of the wavelet-decomposed bands of the RRI data. The classification is done on the whole record as OSA patient or non-patient (normal). The ratio of the estimated entropy of the low-frequency (LF) band to that of the very-low frequency (VLF) band is used as a classification factor. RRI data used in this work are drawn from MIT database. The MIT trial records are used to set the threshold value of the classification factor using the Receiver Operating Characteristics (ROC). This threshold value is used then to classify the MIT challenge (test) records to obtain the efficiency of classification. The new algorithm classifies correctly 30/30 of MIT-test data using different wavelet filters. Comparison of the results of different wavelet filters is done in terms of complexity and distance parameters. The method is also compared with other two techniques using wavelets in their analysis. The consistency of the results is examined using the leave-one-out technique.

Adult↗
PubMed2005

Molecular voting for glioma classification reflecting heterogeneity in the continuum of cancer progression.

Gliomas, the most common brain tumors, are generally categorized into two lineages (astrocytic and oligodendrocytic) and further classified as low-grade (astrocytoma and oligodendroglioma), mid-grade (anaplastic astrocytoma and anaplastic oligodendroglioma), and high-grade (glioblastoma multiforme) based on morphological features. A strict classification scheme has limitations because a specific glioma can be at any stage of the continuum of cancer progression and may contain mixed features. Thus, a more comprehensive classification based on molecular signatures may reflect the biological nature of specific tumors more accurately. In this study, we used microarray technology to profile the gene expression of 49 human brain tumors and applied the k-nearest neighbor algorithm for classification. We first trained the classification gene set with 19 of the most typical glioma cases and selected a set of genes that provide the lowest cross-validation classification error with k=5. We then applied this gene set to the 30 remaining cases, including several that do not belong to gliomas such as atypical meningioma. The results showed that not only does the algorithm correctly classify most of the gliomas, but the detailed voting results also provide more subtle information regarding the molecular similarities to neighboring classes. For atypical meningioma, the voting was equally split among the four classes, indicating a difficulty in placement of meningioma into the four classes of gliomas. Thus, the actual voting results, which are typically used only to decide the winning class label in k-nearest neighbor algorithms, provide a useful method for gaining deeper insight into the stage of a tumor in the continuum of cancer development.

Algorithms↗
PubMedDate not supplied

Classification of recurrent esophageal cancer after radical esophagectomy with two- or three-field lymphadenectomy.

BACKGROUND: Although patients with recurrent diseases have a very poor prognosis, appropriate pretreatment classification for management of recurrent esophageal cancers has yet to be identified. The patterns of recurrence following radial esophagectomy were retrospectively assessed, and evaluated for possible adaptation as a novel classification of recurrent esophageal cancer. PATIENTS AND METHODS: One hundred and sixty thoracic esophageal cancer patients (142 men; 18 women), who underwent radical esophagectomy without preoperative treatment, were studied. RESULTS: Recurrence occurred in 59 (36.8%) patients. The relationship between recurrence and clinicopathological features revealed significant associations between recurrence and age at surgery (p<0.05), tumor (p<0.0001), lymph node (p<0.0001) and metastatic status (p<0.01), pathological stage (p<0.0001) and lymph node dissection (p<0.0001). Locoregional recurrence occurred in 13 (22%) patients, distant in 30 (51%) and mixed in 16 (27%). Mixed recurrence occurred the fastest and showed the poorest prognosis. A novel classification for recurrent esophageal cancer was proposed based on the clinical findings. Univariate analysis of the prognostic factors for post-recurrent survival revealed a significant association with distant organ recurrence (p<0.05). CONCLUSION: Mixed recurrence had a poorer outcome than other recurrences. The proposed classification of clinical findings for recurrent esophageal cancer was shown to be useful; however, further studies with a larger number of recurrent esophageal cancers are required for stage grouping of the proposed classification.

Adult↗
PubMedDate not supplied

[The applicability of the International League Against Epilepsy classification. A retrospective study in a Uruguayan hospital].

INTRODUCTION: Epileptic seizures account for 30-40% of the visits to our department. A retrospective study was conducted in an attempt to classify epileptic syndromes and seizures according to the classification developed by the International League Against Epilepsy (ILAE). AIMS: The aim of this study was to verify the applicability of the ILAE's international classification in our population and to analyse the quality of the information contained in the clinical records, thus confirming the importance of having a standardised clinical record. PATIENTS AND METHODS: The clinical records of 352 children aged between 0 and 14 years, between 2000 and 2001, were analysed. The eligibility criterion was determined by the reason for visiting: epilepsy or seizures with an epileptic mechanism. Data was collected according to a protocol that was drawn up for this purpose. RESULTS: Of the 352 cases, 21.3% had febrile seizures; 13.6% had a single seizure; 4.5% had neonatal convulsions; 54.5% were cases of epilepsy and 6% could not be analysed due to a shortage of data. In all, 192 clinical records that satisfied the definition of epilepsy were analysed. Partial epilepsies accounted for 55%, 23% were symptomatic and 2% were cryptogenetic. It was found that 10% of the generalised epilepsies were idiopathic. CONCLUSIONS: Despite the shortcomings in the documentation, the international classification was applicable to our population, as has been the case in other centres. Nevertheless, we came up against some problems, and therefore include some of the more notable points from the current discussion about classifications. We highlight the need to establish a standardised clinical record and to use computer systems to record epileptic patients. Although there were certain limitations, 81.3% of the epilepsies were classified and we therefore give some consideration to the new proposals for classification.

Adolescent↗
PubMedDate not supplied

[Evolution of the classification of acute and chronic transplant rejection].

In the last twenty years, several systems have been proposed to codify renal allograft rejection. The Banff classification for kidney allograft pathology, introduced in 1993, started a new era in the standardization of criteria for rejection and for allowing uniform reporting. This consensus on allograft grading proposed a scheme to guide therapy in transplant patients and to help establish an objective rejection end point in clinical trials. This scheme, modified during 1993-1997 to address many of the criticisms, was substantially improved. Another important system of classification of allograft renal biopsies was the Cooperative Clinical Trials in Transplantation (CCTT) classification which was published in 1997. The aim of this system was to develop a schema that would be practical to implement, easy to describe to unfamiliar personnel, reproducible, with high rates of sensitivity and specificity and clinically informative (predictive of course and/or response to therapy). In March 1997, a fundamental revision of the Banff classification for acute rejection was achieved by a consensus conference for incorporating many of the strengths of the CCTT system. Some of these were the importance of vascular damage (endoarteritis, endothelial activation, fibrinoid necrosis) and interstitial hemorrhage, but not the interstitial infiltrate or tubulitis, which correlated with response to anti-rejection therapy and/or 1 year clinical outcome. The most recent modification concerns the addition of C4d-positive acute humoral rejection and the emphasis on differences between cell-mediated and antibody-mediated rejections. Future refinements of these classifications and findings of new molecular markers of allograft rejection, such as fas-ligand or granzyme-B, will help to improve diagnosis and therapy in renal transplant patients.

Acute Disease↗
PubMed2006

Known pitfalls of the thyroid neoplasm diagnostics in the view of the new (2004) WHO Classification.

The new (2004) WHO Classification of Tumours of the Thyroid and Parathyroid Gland exhibits both formal and contentual changes compared to the previous one from the year 1988. Comparing both texts we have tried to apply the new norm to some recent diagnostic tasks. The classification of poorly differentiated and undifferentiated neoplasms has been successfully solved by employing the immunohistochemical procedures into the daily routine. Nevertheless, some diagnostic problems persist and can not be solved this way. This is true especially for the borderline neoplasm in the FVPTC category and even more for its oncocytic variant. There appeared shift in the criteria for the diagnosis of oncocytic variant of papillary carcinoma. Newly, the obligatory presence of the nuclei with the characteristics of the conventional papillary neoplasms is required. Thorough elaboration of the TNM system has solved the problem of multifocal lesion staging. Moreover, a web consultation source is recommended. The new Classification includes descriptions of the basic cytodiagnostic features. The post aspiration capsular damage consideration in relation to the diagnosis of the minimally invasive follicular carcinoma is one practical profit thereof. In terms of formal logic a criticisable feature of the new classification is the introduction of the so called "Synonyms". These listings include in fact partly real synonyms by definition, but together in one table quite often also subunits or variants of the nosologic units described. In general, the new Classification represents a successful consensus reached. As there are newly also references with varying opinions included, it is presented more like a point of gravity in this field than an undoubted truth. This also makes it a valuable and useful normative text.

Humans↗
PubMed2005

[Correlations of novel histological classification of 82 thymoma patients to their clinical characteristics and prognosis].

BACKGROUND & OBJECTIVE: The World Health Organization (WHO) histological classification of thymoma was published in 1999. This study was to investigate the correlations of WHO histological classification of thymoma to its clinical characteristics and prognosis. METHODS: Records of 82 thymoma patients treated with surgery were reviewed retrospectively. Histological diagnosis based on WHO classification system was made by an experienced pathologist. The correlations of WHO histological classification of thymoma to its clinical characteristics and prognosis were analyzed. RESULTS: Of the 82 cases, 5 (6.1%) were type A, 21 (25.6%) were type AB, 14 (17.1%) were type B1, 12 (14.6%) were type B2, 14 (17.1%) were type B3, and 16 (19.5%) were type C; according to Masaoka clinical staging system, 29 (35.4%) were in stage I, 13 (15.8%) in stage II , 32 (39%) in stage III , and 8 (9.8%) in stage IVa. The histological subtype of thymoma was significantly correlated with clinical stage (chi2 = 47.29, P < 0.001) and tumor invasive degree (chi2 = 30.78, P < 0.001). Complete resection rate was significantly higher in patients with type A, AB, B1 or B2 tumors than in patients with type B3 or C tumors (84.6% vs. 50.0%, chi2 = 11.29, P = 0.002). The 5-year survival rates of patients with stage I, II, III , and IVa were 100%, 100%, 69.5%, and 37.5%, respectively; the 10-57.1%, year survival rates were 88.1%, 47.5, and 0, respectively. The difference of survival rates among different clinical stages (log-rank = 40.31, P < 0.001) and histological subtypes (log-rank = 16.0, P = 0.007) were significant. CONCLUSION: To some extent, the WHO histological classification reflects the biological behavior and clinical characteristics of thymoma, and may be helpful in diagnosing and treating thymoma.

Adolescent↗
PubMed2005

Representing critical care data using the clinical care classification.

Concept-oriented terminologies require the user to combine terms, making them awkward for their direct use as a documentation tool. Therefore, classification systems are needed to serve as interface terminologies between the user and the reference terminology used to organize the computer database system. Whether nursing classification systems provide sufficient granularity to adequately capture nursing practice is controversial. In addition, no nursing classification systems have been designed specifically for or evaluated in the critical care setting. The purpose of this study was to evaluate the ability of the Clinical Care Classification (CCC) to represent data in an intensive care setting and to provide recommendations for the expansion of this classification for its use in critical care documentation.

Critical Care↗
PubMed2005

Use of description logic classification to reason about consequences of penetrating injuries.

The consequences of penetrating injuries can be complex, including abnormal blood flow through the injury channel and functional impairment of organs if arteries supplying them have been severed. Determining the consequences of such injuries can be posed as a classification problem, requiring a priori symbolic knowledge of anatomy. We hypothesize that such symbolic knowledge can be modeled using ontologies, and that the reasoning task can be accomplished using knowl-edge representation in description logics (DL) and automatic classification. We demonstrate the capabilities of automated classification using the Web Ontology Language (OWL) to reason about the consequences of penetrating injuries. We created in OWL a knowledge model of chest and heart anatomy describing the heart structure and the surrounding anatomic compartments, as well as the perfusion of regions of the heart by branches of the coronary arteries. We then used a domain-independent classifier to infer ischemic regions of the heart as well as anatomic spaces containing ectopic blood secondary to the injuries. Our results highlight the advantages of posing reasoning problems as a classification task, and lever-aging the automatic classification capabilities of DL to create intelligent applications.

Anatomy↗
PubMed2005

The effect of feature representation on MEDLINE document classification.

This work explores the effect of text representation techniques on the overall performance of medical text classification. To accomplish this goal, we developed a text classification system that supports the very basic word representation (bag-of-words) and the more complex medical phrase representation (bag-of-phrases). We also combined word and phrase representations (hybrid) for further analysis. Our system extracts medical phrases from text by incorporating a medical knowledge base and natural language processing techniques. We conducted experiments to evaluate the effects of different representations by measuring the change in classification performance with MEDLINE documents from the OHSUMED dataset. We measured classification performance with information retrieval metrics; precision (p), recall (r), and F1-score (F1). In our experiments, we achieved better classification performance with the hybrid approach (p=0.87, r=0.46, F1=0.60) compared to the bag-of-words approach (p=0.85, r=0.44, F1=0.58) and the bag-of-phrases approach (p=0.87, r=0.42, F1=0.57).

Abstracting and Indexing↗
PubMed2006

Dukes' classification as a prognostic factor in patients with squamous cell carcinoma of the thoracic esophagus undergoing combined-modality treatment.

BACKGROUND: Several disadvantages of the TNM classification have resulted in a search for a simpler, clearer, and more reliable staging system for esophageal cancer. We evaluated Dukes' classification as a prognostic indicator in 81 patients with squamous cell carcinoma of the thoracic esophagus treated with combined-modality therapy. MATERIAL/METHODS: The pathological staging was determined according to the TNM and Dukes' classification. The cumulative survival rates were calculated using the Kaplan-Meier method. The differences in survival between the patients in particular stages of both classifications were estimated with the log-rank test. RESULTS: The differences in cumulative survival rates between TNM I and TNM IIa, between TNM IIa and TNM IIb and between TNM IIb and TNM III patients were 20.2% (37.2 vs. 46.6), 27.5% (46.6 vs. 33.8) and 60.7% (33.8 vs. 13.3), respectively, and were not statistically significant (P = 0.58, P = 0.53 and P = 0.18). The cumulative survival rates for TNM III and TNM IV patients were similar (13.3 and 14.3). The difference in cumulative survival rates between Dukes' A and B patients amounted to 52.5% (54.3 vs. 25.8), which was statistically significant (P = 0.02). The difference in cumulative survival rates between Dukes' B and C patients was 41.5% (25.8 vs. 15.1), but fell short of statistical significance (P = 0.12). The cumulative survival rates for Dukes' C and D patients were similar (15.1 and 16.6). CONCLUSIONS: Dukes' staging system for esophageal cancer is simpler, clearer and more accurate, and could thus be a better prognostic tool than the TNM classification.

Adult↗
PubMed2006

Role of FAB classification of acute leukemias in era of immunophenotyping.

French-American-British classification for leukemias had been widely accepted due to its objectiveness and good reproducibility. WHO classification of leukemias was formulated in 1997 with a purpose of further enhancing the objectivity. However, the requirement of cytogenetics and immunophenotyping makes it difficult for many countries like India to put WHO classification in routine use. This study was carried to know the effectiveness of FAB classification in an era of technical advancement. A retrospective analysis of all acute leukemias over a period of 2 years was done. Out of total of 469 cases of acute leukemias, 193 were diagnosed as Acute Lymphoblastic Leukemia (ALL), 200 as Acute Myeloid Leukemia (AML), and 76 cases diagnosed as Acute Leukemia, cytochemically undifferentiated. Hence, only 16% of all leukemias remained unclassifiable. Subclassification of AML cases revealed a much higher percentage of AML-M3, as compared to western literature. In conclusion, FAB classification, based on morphology and simple cytochemical stains, remains effective enough, although cytogenetics and immunophenotyping can add to diagnostic accuracy in some cases.

Acute Disease↗
PubMed1991

Classification of arrhythmias.

In view of the broad spectrum of arrhythmias and their considerable spontaneous variability, there is a need for a classification of arrhythmias as a basis for scientific and clinical decision making. From the clinical point of view, a classification should consider (a) hemodynamic consequences, (b) prognostic significance of arrhythmias, and (c) should allow assessment of efficacy of antiarrhythmic treatment. Hemodynamic consequences of tachycardias are related to the degree of heart rate: The shorter the RR interval the shorter the diastolic filling period, resulting in a decrease of the stroke volume and--above a critical heart rate--in a decrease of the cardiac output. The critical heart rate, on the other hand, is essentially related to the functional status of the heart: The more pronounced the cardiac impairment, the lower the critical heart rate. A second factor favoring hemodynamic impairment due to arrhythmias is the loss of the sequence of atrioventricular contractions. Despite the clinical relevance of hemodynamic consequences of arrhythmias, there is no accepted classification taking these aspects into account. In the past, more interest was directed toward the prognostic significance of arrhythmias. In 1971, Lown and Wolf published a classification of ventricular arrhythmias, assigning risk to advanced grades. This proposal, as those from others, took into account arrhythmias of ventricular origin only. The major concern about the Lown classification, however, relates to the consequences of maximal grading: a patient is assigned to a grade depending on the highest ranking. Thus, a person can only be in one grade, leaving all other arrhythmias grouped below as well as the true frequency of ventricular arrhythmia obscure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Modified classification of xerophthalmia.

"There are many classifications of xerophthalmia in existence. In the present study all these classification have been exhaustively reviewed. Many objections to previous classifications have been raised following experiences with these classifications for over six years. Based on these objections a self explanatory, easy to remember and modified classification has been proposed, which will be of use in wider areas."

Humans↗
PubMedDate not supplied

Current problems and future requirements for 5-hydroxytryptamine receptor classification.

The present scheme for classifying and naming 5-hydroxytryptamine (5-HT) receptors is being challenged by a growing number of reports that describe receptor types that fail to meet the criteria for admission into the "5-HT1-like," 5-HT2 or, 5-HT3 classes. Consequently, there is an increasing tendency for authors to make unilateral designations for new receptor classes in the absence of any formal criteria for their classification. This hinders rather than helps in establishing the minimum safe criteria for receptor definition and emphasizes the need to update the current scheme. In this article a number of factors are considered that might contribute to instability in 5-HT receptor classification and attention is drawn in particular to the generally unreliable behavior of available chemically heterogeneous antagonists. Experiments with tryptamine agonists and antagonists, although limited in number, suggest that close chemical analogs of the natural receptor agonist 5-HT provide a quantitatively stable and therefore more secure basis for classification, which usefully complements and extends the currently accepted proposals. Furthermore, an approach based on hormone analogs focuses attention on the objectives of the classification process as well as a definition for the term receptor. These issues are germane to the development of a unifying scheme for receptor taxonomy and have been considered here in terms of the current problems and future requirements of 5-HT receptor classification.

Animals↗