Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “classifier”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 937 records · Page 52Linked to original sources
PubMed1979

Ten-year mortality from coronary heart disease among 172,000 men classified by occupational physical activity.

A cohort of 172,489 males aged 20--64 years and employed by the Italian railroad system on 1 April 1963 have been classified by habitual physical activity at work and followed-up for death during a ten-year period. The overall crude mortality was 56.59 per 1,000 in ten years, and no significant differences were found between men in sedentary, moderate and heavy work. Age-corrected death rates for coronary heart disease, as manifested by myocardial infarction and sudden coronary death, were substantially different in the three activity groups, moderately active workers ranking first, sedentary workers second, but very close to the former, and very active workers being last. The age-corrected rates for all ages were 14.18, 12.55 and 7.63 per 1,000 in ten years, respectively. All differences were statistically significant, the mortality ratio between the sedentary and moderate groups combined versus the heavy group being of the order of 1.75 to 1.

Adult↗
PubMed2005

Local classifiers for evoked potentials recorded from behaving rats.

Dynamic states of the brain determine the way information is processed in local neural networks. We have applied classical conditioning paradigm in order to study whether habituated and aroused states can be differentiated in single barrel column of rat's somatosensory cortex by means of analysis of field potentials evoked by stimulation of a single vibrissa. A new method using local classifiers is presented which allows for reliable and meaningful classification of single evoked potentials which might be consequently attributed to different functional states of the cortical column.

Algorithms↗
PubMed1995

Maternal and neonatal outcome of patients classified according to the Australasian Society for the Study of Hypertension in Pregnancy Consensus Statement.

OBJECTIVE: To outline the maternal and perinatal features and outcome of patients referred to a tertiary referral obstetric hospital for management of their hypertension. SETTING AND PATIENTS: 205 consecutive public patients admitted for assessment of hypertension (either full admission or day-stay) to King George V Hospital's Hypertension in Pregnancy Unit, between February 1993 and January 1994. DESIGN: A prospective study in which patients were classified according to the Australasian Society for the Study of Hypertension in Pregnancy (ASSHP) Consensus Statement classification. RESULTS: Of the 205 patients, 25% did not meet the criteria for pre-eclampsia or chronic hypertension, 33% had mild pre-eclampsia, 34% had severe pre-eclampsia and the remainder had chronic hypertension. The mean gestation at delivery for those with mild pre-eclampsia was 38.3 weeks and for severe pre-eclampsia 35.3 weeks. For the mild and severe groups respectively, the rate of elective delivery for raised blood pressure was 56% and 53%; for caesarean section, 17% and 61%; and for perinatal death, 2% and 4%. In the severe group, 49% had fetal problems and 25% required intravenous antihypertensives. CONCLUSIONS: The multisystem nature of pre-eclampsia makes comparison of management protocols difficult. Ongoing audit is needed of maternal and perinatal outcomes and features of disease in patients with hypertension in pregnancy under a universal classification. The ASSHP classification system successfully identifies patients who require more intensive management and intervention.

Chronic Disease↗
PubMed1991

[An attempt to classify vascular impotence using penile erection curve patterns].

Papaverine hydrochloride was administered to the cavernous body of the penis in a total of 262 patients who were diagnosed as impotent at our Reproduction Center, Toho University, during the 5 years' period from 1984 to 1988. The condition of erection was accurately recorded by the use of both a mercury strain gauge and rubber strain gauge to classify the erection curve, and papaverine hydrochloride outflow into the peripheral blood was concurrently measured in some of the cases in order to assess its relation with the erection curve pattern. As for the concentration of papaverine hydrochloride in the peripheral blood, it was found that the better the state of erection, the smaller the outflow of peripheral blood. An assessment of the relationship of the concentration of papaverine hydrochloride with the classification of erection pattern showed that the amount of outflow was smaller in the N type (normal) pattern and that the amount of outflow was increasingly larger in the following order: A type (arterial), N' type (arterial and venous) and V type (venous). The distribution of the erection curve patterns, in the 262 cases was: N type, 45%; A type, 10%; N' type, 22.5%; and V type, 22.5%. From the above findings, it is presumed that classification of erection curve pattern under papaverine hydrochloride loading is useful for the differentiation of vascular impotence, particularly for the diagnosis of disorders in the outflow system.

Adult↗
PubMed2025

A Prospective Validation of the Decipher Genomic Classifier in Men With Early Localized Prostate Cancer: The VANDAAM Study.

BACKGROUND: The emergence of genomic precision oncology has advanced personalized care for some patients with prostate cancer (PCa), while threatening to widen existing disparities due to the historically low recruitment of African American men (AAM), who have the highest disease burden. Here, we report the first prospective validation of a genomic classifier (GC) to predict rapid-onset biochemical recurrence (BCR) in AAM. METHODS: Between 2016 and 2021, this multicenter prospective validation study recruited 243 patients with low- or intermediate-risk PCa who received treatment for their disease. Patients were recruited on a 1:1 basis (AAM:White) and matched by CAPRA score. Patients who elected active surveillance were ineligible for participation. Decipher GC testing was ordered for all patients using their biopsy and/or radical prostatectomy (RP) tumor tissue. The primary outcome was to determine whether the GC could predict 2-year BCR rates-used as a surrogate for disease aggressiveness-following standard treatment. The secondary outcome evaluated the concordance between biopsy- and RP-derived GC risk scores for treatment recommendations. RESULTS: The final analytical cohort included 226 matched patients with genomic information, and 207 evaluable cases (104 AAM, 103 White) with both genomic and complete clinical outcome data. Overall, a high genomic-risk GC score was associated with a 5.25-fold increase in the odds of rapid-onset 2-year BCR compared with the low-risk group (odds ratio, 5.25 [95% CI, 1.27-21.66]; P=.021). In a subset of the surgical cohort (n=74), biopsy- and RP-derived GC scores exhibited a 77% concordance rate, defined as no reclassification in GC risk-based categories. CONCLUSIONS: This study represents the first prospective validation of GC performance in predicting early 2-year BCR in both AAM and White men. The findings provide strong evidence supporting the integration of the GC into clinical practice guidelines to improve risk stratification and management of AAM with early-stage PCa. CLINICALTRIALS: gov identifier: NCT02723734.

Aged↗
PubMed1999

[Rohypnol should be classified as a narcotic].

Flunitrazepam, widely known by its trade names (e.g. Rohypnol), may cause severe violence, especially in combination with alcohol. Flunitrazepam abusers become cold-blooded, ruthless and violent, and do not remember their violence. Reputedly it is supplied to professional hit-men and enforcers by their bosses to promote ruthless efficacy. One case report describes how a young man, intoxicated with flunitrazepam and involved in causing serious knife and gunshot wounds and taking hostages, felt so invincible that he openly challenged the police, threatening them with an assault rifle, but was himself shot. Flunitrazepam may exert pharmacological effects on GABA-ergic systems, thus lowering serotonin levels. The impulsive execution of violent crimes and suicide attempts in which a violent method (hanging, shooting, self-stabbing) has been used are associated with the presence of low serotonin levels. It is therefore recommended that flunitrazepam should be classified as a controlled substance in Sweden as it is elsewhere.

Adult↗
PubMed1994

Classifying quality initiatives: a conceptual paradigm for literature review and policy analysis.

This article presents a conceptual paradigm by which health care executives and other interested parties can classify and organize the extant literature on quality improvement in health care. The paradigm also has utility as an operational tool by which health care managers may locate conceptually their own institutional efforts at quality improvement within the realm of possible action.

Health Services Research↗
PubMed1997

Determining when a clinical activity should be classified as research requiring Institutional Review Board Review.

The boundary between therapy and research may at times be difficult to distinguish, and it is, therefore, important for health care professionals to recognize when a clinical activity should be properly classified as research. Research may be subject to federal regulations which require advance review and approval by an Institutional Review Board (IRB) in order to protect the rights and welfare of patients who serve as human subjects. This paper will discuss the criteria health care professionals can use to distinguish between therapy, innovative therapy, and therapeutic or clinical research.

Clinical Trials as Topic↗
PubMed1997

Computer image analysis of ultrasound images for discriminating and grading liver parenchyma disease employing a hierarchical decision tree scheme and the multilayer perceptron neural network classifier.

Differential diagnosis of liver parenchyma disease and grading of the hepatic disease on ultrasound is a common radiological problem that influences patient management. The aim of this study was to apply image analysis methods on ultrasound images for discriminating liver cirrhosis from fatty liver infiltration and for grading hepatic disease, which is important in the management of the patients. Ultrasound images of histologically confirmed 18 livers with cirrhosis, 37 livers with fatty infiltration, and 24 normal livers of healthy volunteers were selected and were digitized for further computer processing. Twenty two textural features were calculated from small matrix samples selected from the ultrasound image matrix of the liver parenchyma. These features were used in the design a three level hierarchical decision tree classification scheme, employing the multilayer perceptron neural network classifier at each hierarchical tree level. At the first tree level, classification accuracy for distinguishing normal from abnormal livers was 93.7%, at the second level the accuracy for discriminating cirrhosis from fatty infiltration was 90.9%, and at the third level the accuracy in distinguishing between low and high grading liver cirrhosis or fatty infiltration was 94.1% and 84.9% respectively. The proposed computer software system may be of value to the radiologists in assessing liver parenchyma disease.

Decision Trees↗
PubMed1997

Use of statistical classifiers as support tools for the diagnosis of iron-deficiency anemia in patients on chronic hemodialysis.

Discriminant analysis, logistic regression and neural network models were applied to the diagnosis of iron-deficiency anemia in hemodialyzed patients. The ability of the three quantitative approaches to distinguish between subjects suffering or not from iron-deficiency anemia was compared by re-substitution and cross-validation testing. Methods performance was evaluated by means of sensitivity, specificity and accuracy. All the methods performed globally well (sensitivity and specificity > 0.85), revealing that the problem is classifiable. Neural networks showed the highest accuracy, both in the re-substitution (models developed and tested on the complete data set) and 3-way cross-validation (data set randomly splitted into 3 developmental and validation data sets) testing. These preliminary results suggest that the correct classification of iron status in the hemodialytic population can be treated as a pattern classification problem, for which neural networks and traditional statistical modelling can be a valuable aid to the clinical diagnosis of iron-deficiency anemia. A better performance of the neural network model must be confirmed through prospective testing on a larger data set.

Anemia, Iron-Deficiency↗
PubMed1985

RUGs and "Medi-Cal" systems for classifying nursing home patients.

Medicare and most state Medicaid programs currently use indirect case-mix measures to determine reimbursement for nursing home care. In the future, however, they probably will incorporate more direct case-mix measures into their payment systems. Care must be exercised in designing a case-based prospective payment system to ensure that its financial incentives motivate providers to expedite recovery, prevent deterioration, and admit heavy-care patients. For example, although use of a services-rendered approach helps guarantee that care will be provided when needed, it also offers providers an incentive to furnish a service regardless of whether it is in the patient's best interest. Consideration must be given to the frequency with which patients are reassessed. The implications of the timing of reassessments for quality of care also must be studied. Ideally, quality would be measured on an outcome basis--that is, payment would depend on whether targeted goals for individual patients are reached--rather than on structural or process measures alone. Two recent classification systems--Resource Utilization Groups and Medi-Cal groups--may serve as models for case-based prospective payment systems. Each method classifies patients into distinct, meaningful categories based on activities of daily living and services received.

California↗
PubMed1999

Can oxypurines plasma levels classify the type of physical exercise?

BACKGROUND: A laboratory-based model able to describe muscle energy status during physical exercise and changes in myofibrillar composition in response to training would be desirable. Lactate and ammonia concentrations are not sufficient for a comprehensive knowledge of these systems. All muscle fibres, irrespective of the type, show ATP depletion and IMP accumulation following exhausting muscular exercise with quantitative differences due to the different concentrations of deaminase. We studied the plasma concentration of metabolites of oxypurine cascade to test their reliability to classify different exercises. METHODS: We studied 52 athletes, measuring plasma metabolites at the beginning and at the end of their specific field exercise (cycle pursuers, 8 cases; soccer players, 19; marathon runners, 25). K3EDTA-blood samples were assayed for plasma hypoxanthine, xanthine, and inosine, using an HPLC technique, as well as ammonia and lactate by means of enzymatic methods. RESULTS AND CONCLUSIONS: Basal oxypurines levels were not different in relation to any specific physical exercise. Post-exercise oxypurines, namely hypoxanthine, were more precise predictors of muscle energy exhaustion than strain intensity or duration. Plasma levels of hypoxanthine may be elevated also in the presence of normal xanthine and uric acid concentrations, due to an exhaustion of the enzymatic pathway, to a reduced activity of xanthine-oxidase or finally to a substrate-dependent inhibition of the process.

Ammonia↗
PubMedDate not supplied

[Use of serologic methods for identifying and classifying some alpha-viruses].

Sindbis group viruses can be indirectly identified and classified. Three antigenic subtypes were distinguished by solid-phase enzyme immunoassay (SPEIA): African, West-Asian, and North-European. The negative plaque suppression test is recommended for identification of new Alphavirus strains for detecting species-specific antigenic determinants, and SPEIA for classification by appurtenance to antigenic subtypes.

Alphavirus↗
PubMed1979

[Validity of scintigraphic and endocrinological methods in classifying autonomous adenomas of the thyroid (author's transl)].

The validity of various scintigraphic and endocrinological methods was assessed in order to classify confirmed autonomous adenomas (AA) and to differentiate AA from euthyroid and hyperthyroid goitres. Methods used included: Measurement of 131J-uptake 6, 24 and 48 hours after 131J-application, before and after suppression by T3, thyroid scanning, count-rate measurement in the AA and the paranodular tissue, and determination of T4. All patients received 131J-therapy (40,000 rads). In 8 out of 30 scintigraphically compensated autonomous adenomas (CAA) there was no TSH response to TRH. 12 cases showed a subnormal TSH response and 10 patients had a normal TSH response. T4-values were increased in only 2 cases. Out of 73 decompensated autonomous adenomas (DAA), 66 cases (90%) had no TSH response and 7 cases showed only a subnormal response. In 48% of DAA T4-levels turned out to be in the hyperthyroid range. Both, scintigraphic and endocrinological tests were found to agree in most cases of DAA. However, the diagnosis of CAA could only be proved on the basis of a scintigraphically confirmed suppressive effect of T3 on the paranodular tissue. Thus, in the individual case, separation of CAA from DAA turned out to be impossible using the results of TRH-test alone.

Adenoma↗
PubMed1999

Progress in Two-Dimensional and Three-Dimensional Ultrasonic Tissue-Type Imaging of the Prostate Based on Spectrum Analysis and Nonlinear Classifiers.

Spectrum analysis of radiofrequency (RF) ultrasonic echo signals often can sense tissue differences that are not visible on conventional ultrasonic images. Spectrum-analysis parameter values combined with other variables, such as serum prostate specific antigen (PSA) concentration, can be classified by neural networks to distinguish effectively between cancerous and noncancerous prostate tissues. Images based on neural network classification of spectral parameters and clinical variables can be advantageous for biopsy guidance, staging, and treatment planning and monitoring. A study based on 644 biopsies from 137 patients showed that these methods are significantly superior to B-mode image interpretation for differentiating cancerous from noncancerous prostate tissues. Using the histologic determination of tissue types as the gold standard, the area under the receiver-operator characteristic (ROC) curve for neural network classification based on spectrum analysis and PSA value for the 644 biopsies was 0.87 +/- 0.04, and the ROC curve are for a level-of-suspicion (LOS) assignment based on B-mode imaging was 0.64 +/- 0.04. Color-encoded and gray-scale images derived from neural network assignment of suspicion for cancer at each pixel location showed remarkable detail and suggested potential clinical value for biopsy guidance using real-time two-dimensional (2D) images and staging, treatment planning, and monitoring using three-dimensional (3D) images.

Journal Article↗
PubMed2000

Classifying clinical decision making: interpreting nursing intuition, heuristics and medical diagnosis.

This is the second of two linked papers exploring decision making in nursing. The first paper, 'Classifying clinical decision making: a unifying approach' investigated difficulties with applying a range of decision-making theories to nursing practice. This is due to the diversity of terminology and theoretical concepts used, which militate against nurses being able to compare the outcomes of decisions analysed within different frameworks. It is therefore problematic for nurses to assess how good their decisions are, and where improvements can be made. However, despite the range of nomenclature, it was argued that there are underlying similarities between all theories of decision processes and that these should be exposed through integration within a single explanatory framework. A proposed solution was to use a general model of psychological classification to clarify and compare terms, concepts and processes identified across the different theories. The unifying framework of classification was described and this paper operationalizes it to demonstrate how different approaches to clinical decision making can be re-interpreted as classification behaviour. Particular attention is focused on classification in nursing, and on re-evaluating heuristic reasoning, which has been particularly prone to theoretical and terminological confusion. Demonstrating similarities in how different disciplines make decisions should promote improved multidisciplinary collaboration and a weakening of clinical elitism, thereby enhancing organizational effectiveness in health care and nurses' professional status. This is particularly important as nurses' roles continue to expand to embrace elements of managerial, medical and therapeutic work. Analysing nurses' decisions as classification behaviour will also enhance clinical effectiveness, and assist in making nurses' expertise more visible. In addition, the classification framework explodes the myth that intuition, traditionally associated with nurses' decision making, is less rational and scientific than other approaches.

Cooperative Behavior↗
PubMed2000

Classification and the need to classify epilepsy.

Epilepsies are a diverse group of disorders with both shared and distinct features. Classification allows a coherent, systematic approach and serves as a 'universal language' between neurologists all over the world. There are two systems of classifications of epilepsies in use today. The International League Against Epilepsy (ILAE) Classification of Epileptic Seizures 1981 divides seizures into 3 morphologic types--generalised, partial and unclassifiable, with subtypes of each. This system has the advantage that seizures can be classified relatively easily and choice of antiepileptic is dictated by seizure type. However, the same patient may have more than one type of seizure either together or sequentially and many patients show a distinct evolution of their illness. This paved the way for another system of classification--the ILAE Classification of Epilepsies & Epileptic Syndromes 1989, which is meant to supplement the previous classification. An epileptic syndrome is defined as an epileptic disorder characterised by a cluster of signs and symptoms occurring together. According to this system, epilepsies are divided into 4 broad groups--localisation related and generalised, undetermined whether localised or generalised and special syndromes. Within the generalised and localised groups, there are further subdivisions into idiopathic, cryptogenic or symptomatic. This classification is complex and many syndromes are not adequately defined. At initial presentation, it may not be possible to identify the syndrome. Only a small proportion of patients fit into specific syndromes and a large proportion fall into non specific categories. For the present then, classification of epilepsy is still being refined. A brief description of major childhood epileptic syndromes according to age at onset is presented.

Adolescent↗