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PubMed1998

Classification of regional lymph node metastasis from gastric carcinoma. German Gastric Cancer Study Group.

BACKGROUND: Classification of lymph node metastasis from gastric carcinoma was based on the localization (International Union Against Cancer/American Joint Committee on Cancer [UICC/AJCC] 1992). The authors analyzed the data of the German Gastric Cancer Study (GGCS) to determine whether the number of involved lymph nodes related to the prognosis independent of their anatomic localization (UICC/AJCC 1997). METHODS: For 477 patients of the GGCS resected for cure (UICC/AJCC R0 resection) who had involved regional lymph nodes and no evidence of distant metastases, the 1992 UICC/AJCC classification was compared with the new UICC/AJCC classification (1997) based on the number of involved lymph nodes (ILN). RESULTS: Two hundred fifty-eight patients (54.1%) had 1-6 ILN, 137 patients (28.7%) had 7-15, and 82 patients (17.2%) had more than 15. When the 1992 and 1997 UICC/AJCC classifications were compared, the prognosis of patients classified as pN1 (n = 187) in the 1992 pN classification was homogeneous, whereas there was a marked lack of homogeneity among the patients classified as pN2 (n = 290). For 103 of 290 patients with 1-6 ILN, the prognosis appeared to be more favorable (5-year survival rate, 45.5%), whereas 137 of 290 patients with 7-15 ILN had an intermediate prognosis (5-year survival rate, 29.7%). Eighty-two of 290 patients had a dismal prognosis, with a 5-year survival rate of 10.4%. There was a highly significant difference in survival (P < 0.0001). Within the groups with 1-6, 7-15, and more than 15 ILN, the localization of ILN did not significantly alter the prognosis. CONCLUSIONS: The UICC/AJCC classification based on the number of involved regional lymph nodes allows for an estimation of prognosis superior to the 1992 classification. In addition, the new classification can now be applied without methodologic problems and seems more reproducible.

Carcinoma↗

PubMed1998

[The TNM classification. Critical review].

The TNM classification was adopted as a means of evaluating bronchopulmonary cancer and has been used since-1996. It is an international classification and has been recognised since 1986 [5]. After a brief review of the former TNM classification the different features of the newly defined classification are specified concerning particularly the definition of T3 and T4 tumours, some malignant T4 pleural effusions and disease of the lymph nodes (N2, N3) as well as a final classification with 5 stages. Some controversy has appeared over the daily use of this classification and are discussed in the recent literature. They are related to: the re-grouping in Stage 1 of patients with different survivals (T1N0M0 and T2N0M0), the resectability of certain T4 tumours involving the carina, the adverse prognosis of invasion of the visceral pleural and above all the definition of N2 mediastinal node disease which groups together patients with a very heterogeneous prognosis. In 1993, a supplemental was published by the International Union Against Cancer (UICC) entitled "Commentary on the Uniform use of TNM". The commentaries referred to the bronchopulmonary cancers that have been re-grouped and included point by point discussion of the TNM classification. Very recently, Moutain has published some revisions of the TNM classification which will be discussed here.

Carcinoma, Non-Small-Cell Lung↗

PubMed1998

[TNM classification: cancer of the stomach].

The 5th edition of TNM Classification was published by the UICC (International Union Against Cancer) in 1997. In the classification of gastric cancer, anatomical subsites and N category were newly published. The new classification and role of the Japanese TNM Joint Committee were described in this paper. The Japanese committee had strongly advocated to continue "the anatomical N classification", because the hazard ratios were more significant for prognosis of patients with gastric cancer, and had many reasonable and scientific advantages. However, the UICC introduced "a new N classification by number of metastatic lymph nodes" because of the difficulty in studying nodes by anatomical classification. The new TNM can not be considered an improved classification, and so we are looking for a more scientific, practical, and internationally acceptable classification.

Humans↗

PubMed1998

Does it matter who answers the race question? Racial classification and income inequality in Brazil.

Previous studies of racial inequality have relied on official statistics that presumably use self-classification of race. Using novel data from a 1995 national survey in Brazil, we find that the estimates of racial income inequality based on self-classification are lower than those based on interviewer classification. After human capital and labor market controls, whites earn 26% more than browns with interviewer classification but earn only 17% more than browns with self-classification. Black-brown differences hardly change: Blacks earn 13% and 12% less than browns with interviewer classification and self-classification, respectively. We contend that interviewer classification of race is more appropriate because analysts of racial inequality are interested in the effects of racial discrimination, which depends on how others classify one's race.

Adolescent↗

PubMed2005

Classification of emergency department chief complaints into 7 syndromes: a retrospective analysis of 527,228 patients.

STUDY OBJECTIVE: Electronic surveillance systems often monitor triage chief complaints in hopes of detecting an outbreak earlier than can be accomplished with traditional reporting methods. We measured the accuracy of a Bayesian chief complaint classifier called CoCo that assigns patients 1 of 7 syndromic categories (respiratory, botulinic, gastrointestinal, neurologic, rash, constitutional, or hemorrhagic) based on free-text triage chief complaints. METHODS: We compared CoCo's classifications with criterion syndromic classification based on International Classification of Diseases, Ninth Revision (ICD-9) discharge diagnoses. We assigned the criterion classification to a patient based on whether the patient's primary diagnosis was a member of a set of ICD-9 codes associated with CoCo's 7 syndromes. We tested CoCo's performance on a set of 527,228 chief complaints from patients registered at the University of Pittsburgh Medical Center emergency department (ED) between 1990 and 2003. We performed a sensitivity analysis by varying the ICD-9 codes in the criterion standard. We also tested CoCo on chief complaints from EDs in a second location (Utah). RESULTS: Approximately 16% (85,569/527,228) of the patients were classified according to the criterion standard into 1 of the 7 syndromes. CoCo's classification performance (number of cases by criterion standard, sensitivity [95% confidence interval (CI)], and specificity [95% CI]) was respiratory (34,916, 63.1 [62.6 to 63.6], 94.3 [94.3 to 94.4]); botulinic (1,961, 30.1 [28.2 to 32.2], 99.3 [99.3 to 99.3]); gastrointestinal (20,431, 69.0 [68.4 to 69.6], 95.6 [95.6 to 95.7]); neurologic (7,393, 67.6 [66.6 to 68.7], 92.7 [92.6 to 92.8]); rash (2,232, 46.8 [44.8 to 48.9], 99.3 [99.3 to 99.3]); constitutional (10,603, 45.8 [44.9 to 46.8], 96.6 [96.6 to 96.7]); and hemorrhagic (8,033, 75.2 [74.3 to 76.2], 98.5 [98.4 to 98.5]). The sensitivity analysis showed that the results were not affected by the choice of ICD-9 codes in the criterion standard. Classification accuracy did not differ on chief complaints from the second location. CONCLUSION: Our results suggest that, for most syndromes, our chief complaint classification system can identify about half of the patients with relevant syndromic presentations, with specificities higher than 90% and positive predictive values ranging from 12% to 44%.

Bayes Theorem↗

PubMed2026

A unified benchmark of supervised and retrieval-based methods for viral genomic sequence classification.

The rapid growth of genomic sequencing demands fast, accurate, and scalable analysis methods. In viral genomic classification, expanding labeled reference collections can make supervised models costly to update and dependent on fixed label sets, motivating retrieval-based genomic classification as a simpler, more flexible alternative. We present a unified benchmark of supervised and retrieval-based methods for viral genomic sequence classification across three viral classification tasks: hepatitis C virus (HCV) genotyping, COVID-19 discrimination, and human papillomavirus (HPV) genotyping. We compare standard sequence encodings (one-hot, k-mers, FCGR) with dense embeddings (dna2vec, DNABERT). For each representation, we evaluate supervised classifiers (Random Forest, Decision Tree, XGBoost) and retrieval-based classification, where sequence vectors are indexed with FAISS and labels are assigned via similarity-weighted k-NN. Furthermore, we benchmark multiple FAISS index types (Flat, IVF, HNSW, IVFPQ, OPQ) to characterize accuracy-speed-memory trade-offs at scale. The results show that XGBoost and retrieval using Flat or IVF indexes achieve strong classification performance under different computational profiles. Compressed indexes such as IVFPQ and OPQ substantially reduce memory usage, although their accuracy loss depends on the dataset and representation. Overall, supervised XGBoost provides a favorable accuracy-size trade-off, while retrieval-based classification remains competitive and allows labeled reference sequences to be incorporated without retraining a global classifier. This benchmark provides practical guidance for selecting sequence representations, classifiers, and vector-search indexes under different accuracy, memory, and update requirements.

Genome, Viral↗

PubMed1999

Subordinate-level object classification reexamined.

The classification of a table as round rather than square, a car as a Mazda rather than a Ford, a drill bit as 3/8-inch rather than 1/4-inch, and a face as Tom have all been regarded as a single process termed "subordinate classification." Despite the common label, the considerable heterogeneity of the perceptual processing required to achieve such classifications requires, minimally, a more detailed taxonomy. Perceptual information relevant to subordinate-level shape classifications can be presumed to vary on continua of (a) the type of distinctive information that is present, nonaccidental or metric, (b) the size of the relevant contours or surfaces, and (c) the similarity of the to-be-discriminated features, such as whether a straight contour has to be distinguished from a contour of low curvature versus high curvature. We consider three, relatively pure cases. Case 1 subordinates may be distinguished by a representation, a geon structural description (GSD), specifying a nonaccidental characterization of an object's large parts and the relations among these parts, such as a round table versus a square table. Case 2 subordinates are also distinguished by GSDs, except that the distinctive GSDs are present at a small scale in a complex object so the location and mapping of the GSDs are contingent on an initial basic-level classification, such as when we use a logo to distinguish various makes of cars. Expertise for Cases 1 and 2 can be easily achieved through specification, often verbal, of the GSDs. Case 3 subordinates, which have furnished much of the grist for theorizing with "view-based" template models, require fine metric discriminations. Cases 1 and 2 account for the overwhelming majority of shape-based basic- and subordinate-level object classifications that people can and do make in their everyday lives. These classifications are typically made quickly, accurately, and with only modest costs of viewpoint changes. Whereas the activation of an array of multiscale, multiorientation filters, presumed to be at the initial stage of all shape processing, may suffice for determining the similarity of the representations mediating recognition among Case 3 subordinate stimuli (and faces), Cases 1 and 2 require that the output of these filters be mapped to classifiers that make explicit the nonaccidental properties, parts, and relations specified by the GSDs.

Classification↗

PubMed2006

Concepts in classification and their relevance to epilepsy.

The classification of the epilepsies was advanced in order to formalize efforts to identify coherent clinical entities and to develop a standardized set of diagnostic terminology for facilitating communication among workers in the field world-wide. The classification initially was, and still is today, based primarily on description and expert opinion. In the era of genomics, neuroimaging and tremendous technological and scientific advances in the neurosciences, it is time to introduce scientific principles and standards into the classification of the epilepsies. Phylogenetic systematics provides an initial model worth studying in this context. While the classification of species cannot be directly applied to the classification of epilepsy syndromes, three general points can be appreciated. (1) In evolutionary biology, there is an operationalized definition of the end point (a species). There is no such definition of a syndrome. (2) There are rules and criteria for the type of evidence and how it is evaluated to determine whether an entity does or does not represent a separate species. There are currently no such rules or criteria for epilepsy syndromes. (3) There is an underlying model (evolution) that generates the diversity among species. With the possible and only partial exception of the idiopathic generalized epilepsies, there are no models to explain the diversity among the epilepsies. Previously held beliefs and convictions must, in time, give way to dispassionate examination of testable scientific hypotheses examined with rigorously collected scientific evidence. Although current classification is in need of revision, it has also come into common use and has great practical utility. Any changes to its form and to the terminology of the classification must be made only after careful deliberation and broad consensus is reached. The change(s) should be based on agreed upon scientific criteria and processes. Any changes should represent major improvements and not merely incremental steps.

Classification↗

PubMedDate not supplied

Proposal of a modified, treatment-oriented classification of odontoid fractures.

BACKGROUND CONTEXT: The classification scheme of odontoid fractures described by Anderson and D'Alonzo is the one most commonly used. However, uncertainty exists in the distinction between Type II and "shallow" Type III fractures. Moreover, fractures at the base of the odontoid (Anderson and D'Alonzo Type II) include a spectrum of injury patterns. PURPOSE: To modify the Anderson and D'Alonzo classification of odontoid fractures based on current clinical treatment options. STUDY DESIGN: Proposal of a modified classification system for odontoid fractures. METHODS: A more precise distinction between Type II and III fractures based on the presence/absence of C1-C2 facet involvement is proposed. A modified classification of Type II fractures based on fracture line obliquity, displacement and comminution is then proposed, because these are factors deemed to influence management. To evaluate the reproducibility of this classification, 52 odontoid fractures were reviewed and classified by four attending spine surgeons and three spine fellows. RESULTS: There was substantial agreement (at least five of seven respondents) in 70% of cases. The overall kappa value for the modified classification system was 0.48, indicating moderate agreement, and there were no differences in kappa values between attending spine surgeons and fellows. CONCLUSIONS: The reproducibility of this system was demonstrated by the moderate agreement observed when applied to odontoid fractures at our institution. The proposed utility of this system is its ability to guide clinical decision making in the treatment of odontoid fractures. Prospective application of this modified classification system and suggested treatment options is now required.

Classification↗

PubMed2003

Classification of perinatal death in a developing country.

OBJECTIVES: To evaluate and compare the three most commonly used perinatal death classification systems: (1) the Nordic-Baltic; (2) the Aberdeen; and (3) the Wigglesworth, and assess their applicability in a developing country (Sudan) with a high perinatal mortality rate, and their justification for practical use in quality assurance and audit activities. METHODS: At Omdurman Maternity Hospital (OMH), Khartoum, Sudan, 166 perinatal deaths were prospectively assessed during a 3-month period (May-August 2000) with a total of 2260 births. Narratives of 166 perinatal deaths were prepared for the purpose of audit. A panel of two Danish and one Sudanese obstetrician categorized the cases according to: (1) the Nordic-Baltic; (2) the Aberdeen; and (3) the Wigglesworth classification. RESULTS: By all three classifications a similar fraction of cases (approx. 85%) were allocated to one category only, and in 15% of cases the assessors were in doubt into which of two categories the cases should be allocated. The necessary information is often not available, giving at least 40% classified as 'unknown' in the Aberdeen classification, whereas the Wigglesworth classification results in an even larger group of unspecified asphyxia. CONCLUSION: Classification of perinatal deaths in developing countries is associated with problems regarding application, validity and usefulness. The Nordic-Baltic classification seems to be most suitable for appropriate stratification using routinely recorded variables and providing categories associated with specific levels of care.

Cause of Death↗

PubMed2002

The conceptual basis for a new classification of the coccidia.

At the joint meeting of the 8th International Coccidiosis Conference and the Annual Scientific Meeting of the Australian Society for Parasitology in Palm Cove, Australia, in July 2001, a Controversial Roundtable was held on 'New classification of coccidia'. The aim of this Roundtable was to stimulate and encourage discussion and debate on current classification schemes for the group of parasitic protozoa known as the eimeriid coccidia. In the past, such classifications have been based only on phenotypic characters such as morphology, ultrastructure, life cycles, and host specificity. However, over the past 10-15 years, molecular phylogenetic studies on taxa of the eimeriid coccidia have revealed that several of the families, subfamilies, and genera that have been erected based on non-molecular characters are paraphyletic. Therefore, this Roundtable was an important forum for initial discussions on how a new and more comprehensive classification of the eimeriid coccidia, which takes into consideration both phenotypic and molecular characters, can be devised. The stimulus came from invited speakers who gave introductions into selected areas of taxonomy and classification. Following these introductions, a more general discussion with the audience addressed potential steps that may be taken in future work. This review is the immediate outcome of the Roundtable. It describes advantages and disadvantages of the use of phenotypic or molecular characters as the base for taxonomic schemes for eimeriid coccidia. It gives specific examples for drawbacks of current classifications based only on phenotypic characters as well as potential pitfalls associated with the use of only molecular phylogenies. It addresses current controversies as well as rules of taxonomy and nomenclature relevant for the eimeriid coccidia. Finally, it recommends the establishment of an international group of scientists to meet on a regular basis, stimulate further discussions, and give direction on how the final goal, i.e. a proposal for a revised, and widely accepted, classification of the eimeriid coccidia, may be achieved.

Animals↗

PubMed2005

A concept for the validation of fracture classifications.

The fracture classification systems currently used most frequently were not developed or validated by rigorous scientific evaluation methods. This paper discusses the classification of fractures from an epidemiological and clinical decision-making perspective and proposes a standardized methodological concept for their development and scientific validation. Classification categories are clinically relevant entities that surgeons should be able to use for diagnosis with sufficient confidence to limit misclassification and associated treatment errors. The process of validation should assess the value of specific clinical information (eg, the use of radiographs or computed tomography scans) in increasing the probability of a correct diagnosis. A 3-phase validation concept is proposed where: 1) classification categories are defined and the classification process using specific diagnostic images is evaluated by experts in a series of agreement studies (reliability, accuracy, likelihood ratios); 2) a multicenter agreement study is conducted among a representative group of future users of the classification; and 3) the classification proposal is applied in the context of a prospective clinical study to assess its clinical usefulness.

Classification↗

PubMed2006

The Tulip classification of perinatal mortality: introduction and multidisciplinary inter-rater agreement.

OBJECTIVE: To introduce the pathophysiological Tulip classification system for underlying cause and mechanism of perinatal mortality based on clinical and pathological findings for the purpose of counselling and prevention. DESIGN: Descriptive. SETTING: Tertiary referral teaching hospital. POPULATION: Perinatally related deaths. METHODS: A classification consisting of groups of cause and mechanism of death was drawn up by a panel through the causal analysis of the events related to death. Individual classification of cause and mechanism was performed by assessors. Panel discussions were held for cases without consensus. MAIN OUTCOME MEASURES: Inter-rater agreement for cause and mechanism of death. RESULTS: The classification consists of six main causes with subclassifications: (1) congenital anomaly (chromosomal, syndrome and single- or multiple-organ system), (2) placenta (placental bed, placental pathology, umbilical cord complication and not otherwise specified [NOS]), (3) prematurity (preterm prelabour rupture of membranes, preterm labour, cervical dysfunction, iatrogenous and NOS), (4) infection (transplacental, ascending, neonatal and NOS), (5) other (fetal hydrops of unknown origin, maternal disease, trauma and out of the ordinary) and (6) unknown. Overall kappa coefficient for agreement for cause was 0.81 (95% CI 0.80-0.83). Six mechanisms were drawn up: cardio/circulatory insufficiency, multi-organ failure, respiratory insufficiency, cerebral insufficiency, placental insufficiency and unknown. Overall kappa for mechanism was 0.72 (95% CI 0.70-0.74). CONCLUSIONS: Classifying perinatal mortality to compare performance over time and between centres is useful and necessary. Interpretation of classifications demands consistency. The Tulip classification allows unambiguous classification of underlying cause and mechanism of perinatal mortality, gives a good inter-rater agreement, with a low percentage of unknown causes, and is easily applicable in a team of clinicians when guidelines are followed.

Cause of Death↗

PubMed2005

Classification images predict absolute efficiency.

How well do classification images characterize human observers' strategies in perceptual tasks? We show mathematically that from the classification image of a noisy linear observer, it is possible to recover the observer's absolute efficiency. If we could similarly predict human observers' performance from their classification images, this would suggest that the linear model that underlies use of the classification image method is adequate over the small range of stimuli typically encountered in a classification image experiment, and that a classification image captures most important aspects of human observers' performance over this range. In a contrast discrimination task and in a shape discrimination task, we found that observers' absolute efficiencies were generally well predicted by their classification images, although consistently slightly (approximately 13%) higher than predicted. We consider whether a number of plausible nonlinearities can account for the slight under prediction, and of these we find that only a form of phase uncertainty can account for the discrepancy.

Classification↗

PubMed2006

Recurrent headache in chinese children: any agreement between clinician diagnosis and symptom-based diagnoses using the International Classification of Headache Disorders (Second Edition)?

There has been a lack of published data on the pattern of recurrent headache in Chinese children. The validity of the International Classification of Headache Disorders criteria has not been evaluated in Chinese children. We performed a retrospective medical record review of 124 children aged <18 years with an International Classification of Diseases coding of headache followed up in a general outpatient clinic in a university-based hospital over a 3-year period (2000-2002). The aims of our study were to (1) study the pattern of recurrent headache in Chinese children and (2) study any agreement between clinical diagnoses made by our board-certified pediatricians and symptom-based diagnoses using the second edition of the International Classification of Headache Disorders (International Classification of Headache Disorders-II). The most common type was unclassified headache (70.2%), followed by infrequent episodic tension-type headache (24.2%) and migraine without aura (5.6%). A family history of headache or migraine was more commonly found in children with infrequent episodic tension-type headache or migraine without aura (P = .0109). The co-occurrence of abdominal pain with infrequent episodic tension-type headache was 30%; for unclassified headache, it was 19.5%. Dysmenorrhea occurred in 7.1% of girls with infrequent episodic tension-type headache and 8.6% of girls with unclassified headache. However, migraine without aura was not associated with abdominal pain or dysmenorrhea. Children with migraine without aura were more frequently referred to child neurologists (P = .0207) and admitted (P = .0000). Neurologic investigations, including electroencephalography, computed tomography, or magnetic resonance imaging of the brain, were performed in less than 30% of cases. Abnormal results were found in only seven cases; with two referred to a neurosurgeon and none requiring surgical intervention. Thus, by using the clinical diagnosis of our board-certified pediatricians as the standard, the sensitivity and specificity of International Classification of Headache Disorders-II-based definition of migraine without aura was 23.1% and 93.4%, respectively, and for infrequent episodic tension-type headache, it was 37.5% and 76%, respectively. The typical characteristics of migraine tend to emerge later and might have led to underdiagnosis of the younger age group, with a higher rate of referral and inpatient management. The new edition of the International Classification of Headache Disorders criteria is still restrictive in clinical practice and might not be able to reflect current pediatric practice. Further studies with a defined study period or recurrent headache might be more useful in analyzing the use of these new International Classification of Headache Disorders criteria in the diagnosis of recurrent headache in children.

Adolescent↗

PubMed2005

An edit script for taxonomic classifications.

BACKGROUND: The NCBI taxonomy provides one of the most powerful ways to navigate sequence data bases but currently users are forced to formulate queries according to a single taxonomic classification. Given that there is not universal agreement on the classification of organisms, providing a single classification places constraints on the questions biologists can ask. However, maintaining multiple classifications is burdensome in the face of a constantly growing NCBI classification. RESULTS: In this paper, we present a solution to the problem of generating modifications of the NCBI taxonomy, based on the computation of an edit script that summarises the differences between two classification trees. Our algorithms find the shortest possible edit script based on the identification of all shared subtrees, and only take time quasi linear in the size of the trees because classification trees have unique node labels. CONCLUSION: These algorithms have been recently implemented, and the software is freely available for download from http://darwin.zoology.gla.ac.uk/~rpage/forest/.

Algorithms↗

PubMed2006

Systematic analysis of classification systems for osteonecrosis of the femoral head.

BACKGROUND: Multiple classification systems for osteonecrosis of the hip have been developed to assist physicians in the diagnosis and treatment of this potentially debilitating disorder. The purpose of this analysis was to delineate the classification systems utilized in reports published since 1985 and, through a comparison of the most commonly used systems, to identify consistent factors that would allow for cross-publication comparisons to be made. METHODS: We performed a PubMed search for reports of outcome studies concerning treatment methods for osteonecrosis of the hip. All studies of reported outcomes with greater than ten patients were included in the analysis. Various classification systems were tabulated to determine usage frequencies. The four most commonly used systems were then analyzed to determine common factors used for classification. RESULTS: One hundred and fifty-seven studies were available for analysis. Sixteen major classification systems that made use of more than one radiographic factor were identified, and nine of these systems had one to five modifications reported throughout the literature. Additionally, eleven other systems made use of single factors obtained from either magnetic resonance imaging or anatomic data. The review revealed that four classification systems accounted for greater than 85.4% of the reported studies. Parameters for these four systems were stratified to allow for uniformity of patient or study evaluation. CONCLUSIONS: This analysis of the reported classification systems for osteonecrosis of the femoral head revealed several similarities between the most commonly used systems. An analysis of patients can be made with any of the four major systems if specific data are collected according to various magnetic resonance imaging and radiographic findings. This approach will allow for easier comparison of studies across different centers. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Classification↗

PubMed1993

[Reproducibility of the use of classifications of causes of death in the context of inquiries in perinatal mortality].

The objective of this study was to verify the reliability of the classifications of perinatal mortality causes. An independent observer coded the cases of perinatal death (n = 152) collected in the Encuesta Confidencial de Mortalidad Perinatal de Barcelona (ECMP, Confidential Perinatal Mortality Inquiry of Barcelona), by using both the Aberdeen classification system (regarding obstetric factors) and the Wigglesworth classification system (according to the initial pathological cause), with the same information used previously by the ECMP Commission. For the Aberdeen classification, the observed concordance index (Po) was 86% and the Kappa coefficient (K) 0.77 (95% CI: 0.68-0.86). For the Wigglesworth classification, the figures were 89% and 0.82 (95% CI: 0.74-0.90), respectively. The disagreement was mainly due to differences in the interpretation of the sequence of death, minimal information available in order to classify the cause of death, and misunderstanding of the existing information. To a lesser extent, the disagreement was caused by a failure to comply with the rules laid down for classifications. The assessment of the causes of death was not significantly influenced by birth weight, gestational age, time of death or the presence of necropsy. These results support the use of classifications of perinatal mortality causes in the context of confidential inquiries.

Autopsy↗