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PubMed1999

Validation of a new classification system for curatively resected colorectal adenocarcinoma.

BACKGROUND: The parameters within which colorectal adenocarcinoma is currently staged are often insufficient for decisions regarding therapy after potentially curative surgery. Consequently, oncologists make frequent use of additional prognostic indicators when assessing individual prognosis and selecting patients for adjuvant systemic treatment. Follow-up programs are generally uniform for all patients, regardless of disease stage and prognosis. As a result, patients with a favorable prognosis are needlessly subjected to stressful, costly follow-up too early and too frequently. This study was conducted to validate a new classification system that is a superior predictor of individual prognosis following curative surgery and may serve as a guide for personalized, cost-effective postoperative management and follow-up. METHODS: A total of 231 American colorectal carcinoma patients who underwent curative resection were retrospectively staged according to a new classification (containing 4 stage-groups) for curatively resected colorectal adenocarcinoma. This classification is based on statistical analysis of the impact on prognosis of numerous characteristics of 363 consecutive Israeli colorectal carcinoma patients who underwent curative resection. All the patients in both cohorts had had surgery at least 5 years previously. The new classification is based on three histologic variables (venous invasion, depth of primary tumor penetration, and regional lymph node status) and a scoring system that correlates higher numeric score with worse prognosis. In both cohorts, the new classification was compared with the Dukes, Astler-Coller, and TNM staging systems for patient distribution and survival (both disease free and cancer-related survival). RESULTS: In both cohorts, the 4 stage-groups of the new classification differed significantly in both the rate of and the time to first recurrence and cancer-related death, with progression from Group 4 to Group 1. Groups of high risk lymph node negative patients were defined, and lymph node positive patients were subdivided according to prognosis. It is suggested that, by using this new classification as a guide, selection for adjuvant systemic treatment may be refined, and postoperative follow-up may be personalized and therefore more cost-effective. CONCLUSIONS: The new classification for curatively resected colorectal adenocarcinoma, based on an analysis of the Israeli cohort and validated in the American cohort, is superior to the Dukes, Astler-Coller, and TNM staging systems as a predictor of individual prognosis, most probably because it incorporates the microscopic forerunner of distant, hematogenous spread (i.e., venous invasion) with the locoregional parameters of extent of disease (i.e., T and N values). It is suggested that the new classification may serve as a guide for more refined selection of patients for adjuvant systemic treatment and for individualized and more cost-effective postoperative follow-up. The new classification is simple and easy to use, requires no sophisticated equipment or tests, and can be applied in any health care system worldwide.

Adenocarcinoma↗

PubMed1999

[Classification of the diabetes according to Hare in cases of pregnant women].

OBJECTIVES: The purpose of this paper was to show that the clinical classification of the diabetes according to Hare, in comparison with that classification according to P. White which is being used at the moment, is more useful in cases of pregnant women. DESIGN: The aim of this work was to compare the obstetric results within White and Hare classes and prove of absence of statistical differences between B and C classes which are distinquished in White's classification as separate one and proving difference between classes B and C as a joined class and R, F, RF classes also joined into one. MATERIALS AND METHODS: As a material for this study we used 489 diabetic pregnant women. The following have been analyzed: frequency of spontaneous birth, induced birth or planned cesarean section, number of vaginal delivery and cesarean section, duration of pregnancy, frequency of premature delivery, weight of the newborn, frequency of hypotrophy and hypertrophy, the Apgar points, frequency of malformation and intrauterine or postnatal death. White and Hare classification have been compared between each other in the light of clinical usefulness. Classes B and C have been joined into one, as B + C, on the basis that only difference between them was duration of diabetes. Class D in White's classification has been ignored as it is not clinically uniform. Classes R, F, RF have been treated as one class. The level of diabetes control has been compared between groups B and C, B + C and R + F + RF and also between groups DM and DM+. The class of pregnancy diabetes has been ignored as that is separate group in both classifications. RESULTS: There were no differences found in obstetric results between classes B and C. The statistically significant differences affecting all the obstetric events have been observed between classes DM and DM+ (in Hare classification) and artificially created classes B + C and R + F + RF (in White classification). The level of dependence was similar in both comparison. CONCLUSION: It seams advisable to simplify White's classification consisting of 10 classes and use the more recent one and simpler Hare classification composed of 3 classes.

Apgar Score↗

PubMed2003

[Evaluation of the clinical classification of new cases of leprosy. Study conducted at the Marchoux Institute in Bamako, Mali].

INTRODUCTION: The difficulties related to the bacilloscopic diagnosis of leprosy, providing a more reliable classification of cases, in 1995 led the WHO to recommend the use of a new classification, in endemic countries, based on clinical criteria alone, in order to simplify the poly-chemotherapeutic regimens. According to our experience in the Marchoux Institute, this classification may lead to errors in diagnosis through overzealous or mis-interpretation of the two forms of leprosy. The aim of our study was to evaluate the concordance between this clinical classification and that based on a bacilloscopic examination. PATIENTS AND METHODS: We conducted a descriptive study of new cases of leprosy seen at the Marchoux Institute, without distinction in gender or age, from January to December 2000. All the patients included underwent clinical examination and a bacilloscopic exploration to provide a double classification. The concordance between the two classifications was assessed using the Kappa test. RESULTS: Two hundred new cases of leprosy were included. Out of 126 clinically multi-bacillary cases, 61 were confirmed bacteriologically, and 65 were false positives. Out of 74 clinical cases with few bacilli, 2 were bacteriologically multi-bacilli. The concordance between the two classifications was average (Kappa=0.40). There was a significant difference between the percentages of multi-bacilli observed in both classifications (p<10(-8)). DISCUSSION: The clinical classification may well overestimate the multi-bacillary form. In the absence of a reliable bacilloscopic apparatus, a more detailed clinical classification of leprosy forms must be developed.

Adolescent↗

PubMed2003

Classification of juvenile idiopathic arthritis: should family history be included in the criteria?

OBJECTIVE: (i) To determine the efficacy of the Durban classification for children with juvenile idiopathic arthritis (JIA) where < 5 joints were involved at onset (with systemic arthritis excluded) by determining the proportion of the cohort that proved to be "unclassifiable"; (ii) to define reasons for cases being "unclassifiable," particularly regarding family history; and (iii) to compare the efficacy of a proposed hierarchical system (an unofficial modification of the Durban classification) with the Durban classification, where family history details are included as descriptors, rather than as classification criteria. METHODS: Charts were reviewed of 50 children with fewer than 5 joints involved at presentation for JIA, followed for at least 12 months, with systemic arthritis excluded. Cases were classified according to the EULAR criteria, the Durban criteria, and by a proposed "modified Durban" classification subject to hierarchy, with exclusions in the following order: systemic arthritis, rheumatoid factor (RF) positive arthritis, psoriasis or a combination of dactylitis and psoriatic nail changes (psoriatic arthritis), and HLA-B27 positive arthritis (enthesitis related arthritis), with the remainder of children being classified as having either RF negative polyarthritis or RF negative oligoarthritis, depending on number of joints involved, with additional information noted as descriptors. The "modified Durban" classification was proposed only to stimulate discussion among clinicians. RESULTS: Of 50 children, 56% were "unclassifiable" by the Durban classification, mainly because of inadequate family history despite appropriate questioning. Using the proposed "modified Durban" classification, 2% were "unclassifiable." Family history was classified as inadequate for the following reasons: The parents did not know family history; the child or parent was adopted; the father was unknown or parent died early; parents never attended; extended family had lost communication with parents; or a relative was considered to have psoriasis, but not confirmed by dermatologists. Other reasons for "unclassifiable" included: dermatologists unable to confirm psoriasis; family history of inflammatory bowel disease and sacroiliitis but B27 status unknown; proband B27 negative but family history of B27-related disease; family history of psoriasis, but patient had insufficient criteria for psoriatic arthritis and therefore excluded from oligoarthritis, psoriatic arthritis and other groups. CONCLUSION: (i) The Durban classification showed poor efficacy for JIA where < 5 joints were involved at onset, with more than half the cases being "unclassifiable". (ii) The most common reason was that appropriate family history was not available despite being sought by the clinician. (iii) A proposed hierarchical system, an unofficial modification of the Durban classification, showed good efficacy, with only one of 50 cases being "unclassifiable."

Arthritis, Juvenile↗

PubMed1992

Relative weight classifications in the assessment of underweight and overweight in the United States.

We compared five recent relative weight classifications based on body mass index for their estimates of prevalence of underweight and overweight in the adult population of the United States and for their ability to predict subsequent morbidity and mortality. The sources of the classifications were: the 1990 Dietary Guidelines for Americans of the US Departments of Agriculture and Health and Human Services, the National Academy of Sciences, the National Center for Health Statistics, the World Health Organization, and the Canadian Minister of National Health and Welfare. These classifications were applied to the body mass index distributions of the second National Health and Nutrition Examination Survey (1976-1980) and to the Hispanic Health and Nutrition Examination Survey (1982-1984). Depending on classification, a wide range of prevalence for the total population was found: 9-17% of the US population were categorized as underweight, and 25-45% were categorized as overweight. White women had the highest prevalence of underweight in all but the National Center for Health Statistics classification. Black and Mexican American women had the highest prevalence of overweight under all classifications (range: 38.4-58.6%). Associations with health outcomes were determined using all cause hospitalization and mortality in the 1971-1987 follow-up of the first National Health and Nutrition Examination Survey. Underweight and overweight as defined by the National Academy of Sciences classification had the highest population attributable risk for hospitalization and death: 5.0% of hospitalizations and 11.0% of deaths among men and 4.2% of hospitalizations and 11.4% of deaths among women were associated with weights outside the healthy range. Under this classification a greater proportion of both hospitalizations and mortality were associated with overweight than underweight. For all classifications, a higher proportion of hospitalizations were associated with overweight than underweight. All classifications performed better at predicting death than hospitalization.

Adult↗

PubMed2005

[An attempt to improve classification of HCV-correlated chronic hepatitis].

To verify the clinical efficacy of the Desmet classification of chronic hepatitis C we reviewed 801 liver biopsies from patients with HCV-chronic hepatitis (CH). The diagnosis of chronic hepatitis was assessed according to the Desmet classification based on the Knodell Histological Activity Index (HAI) (minimal CH=score 1-3; mild CH= 4-8; moderate CH= 9-12; severe CH= 13-18). Liver fibrosis was assessed according to the Scheuer scoring system. One hundred forty-eight patients had cirrhosis and 653 CH. Of these 653, according to the Desmet classification 145 patients showed minimal, 424 mild, 73 moderate and 11 severe chronic hepatitis. Since the classification underestimated the moderate and severe forms of HCV-related chronic hepatitis, we evaluated the possibility of improving the Desmet classification of chronic hepatitis C using our classification: minimal CH= score 1-3; mild CH= 4-6; moderate CH= 7-8; severe CH= 9-18. According to our classification 145 showed minimal CH, 363 mild CH, 61 moderate CH and 84 severe CH. All the 61 patients who crossed over from mild CH under the Desmet to moderate CH under our classification showed a periportal inflammation of grade 3, and all the 73 patients but 8 who crossed over from moderate to severe showed a grade of periportal inflammation higher than 3. The Desmet classification of HCV-related chronic hepatitis underestimated the severe forms of HCV-CH, while our classification seems to be suitable also for chronic hepatitis C.

Adolescent↗

PubMedDate not supplied

[Analysis of inter and intrapathologist concordance and discordance in a comparative study of the Madrid and Ridley-Jopling classifications of leprosy].

Eighty-six patients of leprosy have been examined by three leprologists; they have been classified according to the Madrid classification and their lesions biopsied and sent to two pathologists for independent histopathological examination. The pathologists have not received any information regarding the cases. Firstly the "senior" pathologist (A) utilized the Madrid classification and the "junior" pathologist (B) the Ridley-Jopling classification. In a second phase, the "senior" pathologist utilized the Ridley-Jopling classification and the "junior" pathologist the Madrid classification. Both pathologists did not know their own previous histopathological diagnosis at the second phase. The analysis of concordance and discordance between the histopathological diagnosis of the two pathologists and for the same pathologist, on utilizing the two classifications, have elicited the following conclusions: 1. There has been more concordance between the two pathologists on utilizing the Madrid classification than the Ridley-Jopling classification for the lepromatous, borderline and tuberculoïd in reaction patients. 2. The comparison of the two classifications for each pathologist on "blindly" examination of the material, has shown more concordance for the "senior" pathologist than for the "junior" pathologist. 3. These observations have convoyed to the final conclusion that the Ridley-Jopling classification brings some difficulties to the pathologists with limited experience in leprology and therefore it should be utilized only by experienced pathologists. 4. This preliminary study shows the necessity of performing another one with larger number of patients, in the active phase, with larger number of pathologists, preferably from different countries, and by utilizing the same methodology of "blind" examination of the material.

Humans↗

PubMed1995

[The importance of classifications in psychiatry].

The classifications currently used in psychiatry have different aims: to facilitate communication between researchers and clinicians at national and international levels through the use of a common language, or at least a clearly and precisely defined nomenclature; to provide a nosographical reference system which can be used in practice (diagnosis, prognosis, treatment); to optimize research by ensuring that sample cases are as homogeneous as possible; to facilitate statistical records for public health institutions. A classification is of practical interest only if it is reliable, valid and acceptable to all potential users. In recent decades, there has been a considerable systematic and coordinated effort to improve the methodological approach to classification and categorization in the field of psychiatry, including attempts to create operational definitions, field trials of inter-assessor reliability, attempts to validate the selected nosological categories by analysis of correlation between progression, treatment response, family history and additional examinations. The introduction of glossaries, and particularly of diagnostic criteria, marked a decisive step in this new approach. The key problem remains that of the validity of diagnostic criteria. Ideally, these should be based on demonstrable etiologic or pathogenic data, but such information is rarely available in psychiatry. Current classifications rely on the use of extremely diverse elements in differing degrees: descriptive criteria, evolutive criteria, etiopathogenic criteria, psychopathogenic criteria, etc. Certain syndrome-based classifications such as DSM III and its successors aim to be atheoretical and pragmatic. Others, such as ICD-10, while more eclectic than the different versions of DSM, follow suit by abandoning the terms "disease" and "illness" in favor of the more consensual "disorder". The legitimacy of classifications in the field of psychiatry has been fiercely contested, being variously dubbed "a reductive academic exercise of no relevance to patients", "a dehumanizing labelling system, and a potential source of social and political violence", "a destructive prognostic guide", and so on. Other critics point to various aspects of certain classifications: the abandonment of theoretical concepts, the arbitrary nature of certain categories, the selection of definitions and criteria, the privileged position systematically accorded to the notion of category over that of general dimension. Multiaxial systems such as those proposed in successive versions of DSM or the classifications used in child psychiatry go some way towards meeting these criticisms. They go beyond simple labelling and place the patient in an overall medicopsycho-social setting. Nosographical indicators do not constitute an obstacle to psychopathological understanding. No classifications are capable of satisfactorily fulfilling all needs, namely those of daily practice, research and health statistics. The has led to the development of specialized diagnostic criteria and instruments, as in research for example. It should also be noted in this context that different versions of ICD-10 exist for psychiatrists, general practitioners, researchers and healthcare managers. The greatest danger posed by classifications is the potential reification of hypothetical approaches, arbitrary categorization and the dulling of reflection, all of which have created a need for regular revisions underpinned by field trials.

Humans↗

PubMed1996

Classification of death in antiarrhythmia trials.

OBJECTIVES: We sought to develop and apply a new scheme for the classification of death to be used in trials of antiarrhythmia treatments. BACKGROUND: Because presently accepted classifications of death do not fully describe or tabulate all significant aspects of terminal events, nor do they consider unique aspects of arrhythmia investigations, a new classification scheme that addresses these issues is desirable. METHODS: A classification scheme of deaths that occur in antiarrhythmia trials was developed using the following categories: 1) primary organ cause (cardiac [arrhythmic, nonarrhythmic or unknown], noncardiac or unknown); 2) temporal course (sudden, nonsudden or unknown); 3) documentation (witnessed, monitored [yes, no or unknown]); 4) operative relation (preoperative, perioperative or postoperative); and 5) system relation (procedure related, pulse generator related and lead related [yes, no or unknown]). RESULTS: The classification scheme was used in a clinical trial of a new implantable cardioverter-defibrillator (1,250 patients, of whom 79 died) and used in an application for device market approval. Application of the classification to data reported using an older classification scheme is demonstrated. CONCLUSIONS: We propose a descriptive classification scheme that 1) fully describes and tabulates all significant aspects of terminal events; 2) incorporates previously used categorizations of death and new categorizations that address unique aspects of arrhythmia investigations; and 3) tabulates sufficient data to allow comparison with other studies. Events in a clinical trial of implantable defibrillator therapy were classified using the new classification scheme.

Arrhythmias, Cardiac↗

PubMed2006

Event-related fMRI of category learning: differences in classification and feedback networks.

Eighteen healthy young adults underwent event-related (ER) functional magnetic resonance imaging (fMRI) of the brain while performing a visual category learning task. The specific category learning task required subjects to extract the rules that guide classification of quasi-random patterns of dots into categories. Following each classification choice, visual feedback was presented. The average hemodynamic response was calculated across the eighteen subjects to identify the separate networks associated with both classification and feedback. Random-effects analyses identified the different networks implicated during the classification and feedback phases of each trial. The regions included prefrontal cortex, frontal eye fields, supplementary motor and eye fields, thalamus, caudate, superior and inferior parietal lobules, and areas within visual cortex. The differences between classification and feedback were identified as (i) overall higher volumes and signal intensities during classification as compared to feedback, (ii) involvement of the thalamus and superior parietal regions during the classification phase of each trial, and (iii) differential involvement of the caudate head during feedback. The effects of learning were then evaluated for both classification and feedback. Early in learning, subjects showed increased activation in the hippocampal regions during classification and activation in the heads of the caudate nuclei during the corresponding feedback phases. The findings suggest that early stages of prototype-distortion learning are characterized by networks previously associated with strategies of explicit memory and hypothesis testing. However as learning progresses the networks change. This finding suggests that the cognitive strategies also change during prototype-distortion learning.

Brain↗

PubMed2006

Classification criteria of epileptic seizures and syndromes.

Care must be exercised not to intermingle with classification of seizures and classification of epilepsies in an inconsistent fashion. Criteria for each class must be defined as clearly as possible, and these criteria must be those which are necessary for classifying any given case. The international classification first proposed by the ILAE in 1970 was an attempt to distinguish seizures from epilepsies; the seizure types defined in the 2001 diagnostic scheme are conceptually akin to the syndromes in the 1989 classification in the sense that they imply etiological, therapeutic, and prognostic significance. However, there exists no room in the new diagnostic scheme to accommodate electro-clinical seizure types, which have been used for more than three decades. The concept of epileptic syndrome in the 1989 classifications seems to have been changed to epileptic seizure type in the 2001 diagnostic scheme, and seizure type of the latter virtually becomes synonymous with epileptic syndrome of the former. In the 2001 diagnostic scheme, seizure type can be used to supplement syndrome, and can stand alone when syndrome diagnosis cannot be made. In other words, seizure types may replace syndromes, or vice versa. We should not return to an era prior to 1970 where no distinction exists between epilepsies and seizures. In a cohort of patients with active epilepsy, to what extent is syndrome classification applicable? In 300 consecutive patients hospitalized in a tertiary center, syndromic diagnosis was applicable to only 61%. Similarly, another 100 consecutive patients, classification of epilepsy was possible but not defined as a syndrome in 32% patients, according to the 1989 classification. The 1989 syndrome classification assigned in each category "other epilepsies not defined as a syndrome." These epilepsies are diagnosed only dichotomously; idiopathic focal or generalized, symptomatic focal or generalized, or undetermined whether focal or generalized. In other words, even if we could complete a list to include all the new syndromes that may exist, it is very unlikely that it would cover all epilepsies.

Classification↗

PubMed1989

Syndromology: an updated conceptual overview. II. Syndrome classifications.

There are many ways to classify syndromes. In Part II, some general types of classification are considered including etiologic classification, embryonic/histologic classification, and syndrome prototypes. Polythetic classifications, in which syndromes are grouped because of their overall similarity, are then contrasted with the more commonly used monothetic classifications, in which syndromes are grouped together because they share a single feature in common. The general survey concludes with a discussion of mixed classifications. Finally, two contrasting craniofacial classifications--the Tessier classification and the morphogenetic classification--are considered.

Classification↗

PubMed2000

Rationale of a new classification for the group of primary cutaneous lymphomas.

In the last decade many studies showed that primary cutaneous lymphomas have another clinical behavior and prognosis, and therefore require a different therapeutic approach, as compared with their primary nodal equivalents. Because, until recently, classification systems for non-Hodgkin's lymphomas were purely based on histologic criteria, and did not recognize the special character of these lymphomas, primary cutaneous lymphomas were not uncommonly diagnosed incorrectly and/or treated inappropriately with unnecessarily aggressive therapies. For that reason the Cutaneous Lymphoma Group of the European Organization for Research and Treatment of Cancer (EORTC) proposed a separate classification for the group of primary cutaneous lymphomas. This EORTC classification is consistently based on a combination of clinical, histologic, immunophenotypical and genetic criteria, and includes well-defined and recognizable disease entities. It contains a limited number of cutaneous T-cell lymphomas and cutaneous B-cell lymphomas, which together constitute more than 95% of all primary cutaneous lymphomas. Herein, the rationale and the basic principles of the EORTC classification are presented, and the relationship between the EORTC classification and other recent classification systems, such as the Revised European-American Classification for Lymphoid Neoplasms (REAL classification) and the proposed World Health Organization classification, are discussed.

Classification↗

PubMed2006

Conventional functional classification schemes underestimate the relationship with ecosystem functioning.

Studies linking the functional diversity of a biota to ecosystem functioning typically employ a priori classifications of species into hypothetically complementary groups. However, multiple alternate classifications exist in which the number of functional groups, the number of species per functional group, and the grouping of species differ from the a priori scheme. Without assessing the relative precision, or ability of an a priori scheme to accurately predict ecosystem functioning relative to its many alternatives, the validity and utility of analyses based on a single a priori classification scheme remains unclear. We examine the precision of a priori classifications used in 10 experimental grassland systems in Europe and the United States that have found evidence for a significant role of functional plant diversity in governing ecosystem function. The predictive precision of the a priori classifications employed in these studies was seldom significantly higher than the precision of random classifications. Post-hoc classification schemes that performed well in predicting ecosystem function resembled each other more with regard to species composition than average classifications, but there was still considerable variability in the manner in which these classification schemes grouped species. These results suggest that we need a more nuanced understanding of how the diversity of functional traits of species in an assemblage affects ecosystem functioning.

Classification↗

PubMedDate not supplied

[It is normal for classification approaches to be diverse].

It is asserted that the postmodern concept of science, unlike the classical ideal, presumes necessary existence of various classification approaches (schools) in taxonomy, each corresponding to a particular aspect of consideration of the "taxic reality". They are set up by diversity of initial epistemological and ontological backgrounds which fix in a certain way a) fragments of that reality allowable for investigation, and b) allowable methods of exploration of the fragments being fixed. It makes it possible to define a taxonomic school as a unity of the above backgrounds together with consideration aspect delimited by them. Two extreme positions of these backgrounds could be recognized in recent taxonomic thought. One of them follows the scholastic tradition of elaboration of a formal and, hence, universal classificatory method ("new typology", numerical phenetics, pattern cladistics). Another one asserts dependence of classificatory approach on the judgment of the nature of taxic reality (natural philosophy, evolutionary schools of taxonomy). Some arguments are put forward in favor of significant impact of evolutionary thinking onto the theory of modern taxonomy. This impact is manifested by the correspondence principle which makes classificatory algorithms (and hence resulting classifications) depending onto initial assumptions about causes of taxic diversity. It is asserted that criteria of "quality" of both classifications proper and classificatory methods can be correctly formulated within the framework of a particular consideration aspect only. For any group of organisms, several particular classifications are rightful to exist, each corresponding to a particular consideration aspect. These classifications could not be arranged along the "better-worse" scale, as they reflect different fragments of the taxic reality. Their mutual interpretation depends on degree of compatibility of background assumptions and of the tasks being resolved. Extensionally, classifications are compatible as much as they coincide by context and hierarchical structure of included taxa. Intentionally, typological classifications are compatible if included taxa are comparable by their diagnoses, while phylogenetic classifications are compatible if the included taxa are ascribed monophyletic status. A brief consideration is given to the "new phylogenetics" (= "genophyletics") as to a classificatory approach aimed at elaboration of parsimonious phylogenetic hypotheses based on molecular biology data and employing numerical methods of cladistic analysis. This approach is shown to borrows some phenetic ideas and revives scholastic principle of unified classificatory basis. It is supposed that, in a time, biological classification would get escaping from plethora of positivistic ideas (including those being developed by nowaday cladistics) and would assimilate (revive) more actively holistic worldview.

Biodiversity↗

PubMed1996

The prognostic utility of the Silicone Study Classification System. Silicone Study Report 9. Silicone Study Group.

OBJECTIVE: To evaluate the reproducibility and the prognostic utility of the Retina Society and Silicone Study Classification Systems in eyes after surgery for severe proliferative vitreoretinopathy (PVR). DESIGN: Subgroup analysis of the Silicone Study--a randomized, multicentered, surgical trial. SETTING: Community and university-based ophthalmology clinics. MATERIALS: Three hundred forty eyes with preoperative and intraoperative evaluations using both systems of grading PVR (reproducibility study), and 287 eyes with preoperative and intraoperative evaluations using both systems of grading PVR and with a 24-month follow-up examination (prognosis study). INTERVENTIONS: Vitrectomy for PVR with long-acting perfluoropropane gas or silicone oil as the intraocular tamponade. OUTCOME MEASURES: Retinal reattachment, visual acuity ( > or = 5/200), intraocular pressure, corneal clarity, and the need for reoperation. RESULTS: The reproducibility of the Silicone Study Classification System was 64% (type of contraction), 77% (number of clock hours), 67% (posterior PVR), 88% anterior and posterior PVR), and 94% (anterior, posterior, and subretinal PVR). The reproducibility of the Retina Society Classification System was 99%. Using the Silicone Study Classification System, location of PVR predicted visual acuity (P=.004, chi 2 test for trend) and hypotony (P=.03, chi 2 test for trend). Using the Retina Society Classification System, the grade of PVR predicted only visual acuity (P=.01, chi 2 test for trend). For eyes with anterior and posterior PVR, there was a decreasing trend in successful visual acuity outcome with increasing severity of PVR (from C-3 to D-3, P=.02, chi 2 test for trend). CONCLUSIONS: Although the classification of PVR using the Silicone Study classification System was not reproducible for the type of contraction or for posterior PVR, identification of the anteroposterior extent of the PVR was prognostic of visual acuity and hypotony at 24 months. The joint knowledge of the location of PVR (using the Silicone Study Classification System) and the tightness of the funnel for retinas with 9 to 12 clock hours involved by fixed folds (using the Retina Society Classification System) has prognostic utility for eyes with anterior and posterior PVR.

Adult↗

PubMed1994

Application of neural networks to the classification of giant cell arteritis.

OBJECTIVE: Neural networks are a group of computer-based pattern recognition methods that have recently been applied to clinical diagnosis and classification. In this study, we applied one type of neural network, the backpropagation network, to the diagnostic classification of giant cell arteritis (GCA). METHODS: The analysis was performed on the 807 cases in the vasculitis database of the American College of Rheumatology. Classification was based on the 8 clinical criteria previously used for classification of this data set: 1) age > or = 50 years, 2) new localized headache, 3) temporal artery tenderness or decrease in temporal artery pulse, 4) polymyalgia rheumatica, 5) abnormal result on artery biopsy, 6) erythrocyte sedimentation rate > or = 50 mm/hour, 7) scalp tenderness or nodules, and 8) claudication of the jaw, of the tongue, or on swallowing. To avoid overtraining, network training was terminated when the generalization error reached a minimum. True cross-validation classification rates were obtained. RESULTS: Neural networks correctly classified 94.4% of the GCA cases (n = 214) and 91.9% of the other vasculitis cases (n = 593). In comparison, classification trees correctly classified 91.6% of the GCA cases and 93.4% of the other vasculitis cases. Neural nets and classification trees were compared by receiver operating characteristic (ROC) analysis. The ROC curves for the two methods crossed, indicating that the better classification method depended on the choice of decision threshold. At a decision threshold that gave equal costs to percentage increases in false-positive and false-negative results, the methods were not significantly different in their performance (P = 0.45). CONCLUSION: Neural networks are a potentially useful method for developing diagnostic classification rules from clinical data.

Diagnosis, Computer-Assisted↗

PubMed2003

Primary diagnosis and REAL/WHO classification of non-Hodgkin's lymphoma by fine-needle aspiration: cytomorphologic and immunophenotypic approach.

The Revised European American lymphoma (REAL) and World Health Organization (WHO) classification of non-Hodgkin's lymphoma (NHL) relies on the constellation of cytologic, phenotypic, genotypic, and clinical characteristics of NHL. For the most part, the classification does not rely on architectural pattern for classification of neoplasms. This classification makes it possible to diagnose and classify lymphomas by fine-needle aspiration (FNA). In this study, we attempted to evaluate the accuracy of FNA in diagnosing and classifying NHL within the context of the REAL/WHO classifications. Cases included only those in which FNA was the primary diagnosis, followed by a surgical biopsy for confirmation. Flow cytometry (FCM) for phenotyping was carried out whenever material was available. Two groups of pathologists were identified. Group A consisted of pathologists with background training in cytopathology and/or hematopathology (three pathologists). Group B consisted of experienced surgical pathologists with no training in cytopathology and/or hematopathology (four pathologists). Seventy-four cases were included in the study. FCM phenotyping was performed in 53 cases (71%). Large cell lymphoma constituted 63% of the cases. The remaining lymphomas included Burkitt's, small lymphocytic, lymphoblastic, follicle center cell, Ki-1, mantle cell, marginal zone, and natural killer cell lymphoma. The diagnosis of lymphoma was rendered for all cases. The correct classification was seen in 63% of the cases. Classification was more accurate in immunophenotyped than in nonimmunophenotyped cases (84% vs 33%; P = 0.00004). Group A pathologists showed higher incidence of proper classification than group B (80% vs 56%; P = 0.046). The diagnosis and classification of NHL can be achieved in a large number of cases on FNA material. This accuracy can be increased if cytomorphologic criteria are established for different entities of NHL aided by FCM for phenotyping.

Biopsy, Needle↗