A Novel Sequential Three-Way Decision Model for Medical Diagnosis

In the sequential three-way decision model (S3WD), conditional probability and decision threshold pair are two key elements affecting the classification results. The classical model calculates the conditional probability based on the strict equivalence relationship, which limits its application in reality. In addition, little research has studied the relationship between the threshold change and its cause at different granularity levels. To deal with these deficiencies, we propose a novel sequential three-way decision model and apply it to medical diagnosis. Firstly, we propose two methods of calculating conditional probability based on similarity relation, which satisfies the property of symmetry. Then, we construct an S3WD model for a medical information system and use three different kinds of cost functions as the basis for modifying the threshold pair at each level. Subsequently, the rule of the decision threshold pair change is explored. Furthermore, two algorithms used for implementing the proposed S3WD model are introduced. Finally, extensive experiments are carried out to validate the feasibility and effectiveness of the proposed model, and the results show that the model can achieve better classification performance

A Novel Sequential Three-Way Decision Model for Medical Diagnosis

In the sequential three-way decision model (S3WD), conditional probability and decision threshold pair are two key elements affecting the classification results. The classical model calculates the conditional probability based on the strict equivalence relationship, which limits its application in reality. In addition, little research has studied the relationship between the threshold change and its cause at different granularity levels. To deal with these deficiencies, we propose a novel sequential three-way decision model and apply it to medical diagnosis. Firstly, we propose two methods of calculating conditional probability based on similarity relation, which satisfies the property of symmetry. Then, we construct an S3WD model for a medical information system and use three different kinds of cost functions as the basis for modifying the threshold pair at each level. Subsequently, the rule of the decision threshold pair change is explored. Furthermore, two algorithms used for implementing the proposed S3WD model are introduced. Finally, extensive experiments are carried out to validate the feasibility and effectiveness of the proposed model, and the results show that the model can achieve better classification performance

Large-Scale Genomic Epidemiology of <i>Klebsiella pneumoniae</i> Identified Clone Divergence with Hypervirulent Plus Antimicrobial-Resistant Characteristics Causing Within-Ward Strain Transmissions

Global dissemination of K. pneumoniae clones poses health hazards to the public. Genomic epidemiology studies with comprehensive data set further revealed clone divergence, showing a high complexity in evolution. Moreover, clones carrying both acquired virulent and antimicrobial-resistant genes emerged and might replace the carbapenem-resistant clones. Co-occurrence of virulence and resistance is emerging. An unbiased collection of 3,061 clinical K. pneumoniae isolates (January 5, 2013 to July 24, 2018) underwent whole-genome sequencing. Pairwise core-genome single-nucleotide polymorphism (cgSNP) distances identified clone divergence and transmission events. A sum of 2,193 nonduplicated genomes clustered into four phenotypically indistinguishable species complexes. 93% (n = 2,035) were KpI with its largest clonal group (CG) being CG11 (n = 406). Three hundred ninety-three were ST11 and three hundred seventy-four carried bla(KPC-2). Noticeably, CG11 is divided into two main subclones based on the capsule synthesis K loci (KL). CG11-KL64 showed a clear hypervirulent plus antimicrobial-resistant (hv+AMR) characteristic. Besides, the phylogenetic structure revealed the clone divergence of CG25, and this is the first report with sufficient CG25 genomes to identify the divergence. The outcomes of the hv+AMR CG25 cluster 1 affected patients were poorer (P < 0.05). Moreover, two episodes of strain transmissions were associated with CG25 cluster 1. Other transmissions were associated with ST20 and ST307. Genomic epidemiology identified clone divergence of CG11 and CG25. The hv+AMR subclones pose greater threats on a global scale. Nosocomial transmissions of the high-risk clones raised our concerns about the evolution and transmission of emerging clones among newborns and critically ill patients. IMPORTANCE The convergence of AMR and acquired virulence posing higher risks to the public is a focusing point. With sufficient genomes and genotypes, we successfully identify the convergence in two subclones, the previously reported CG11-KL64, and the newly reported CG25 cluster 1. The novel finding of the CG25 divergence was not only revealed by the phylogenetic tree but also confirmed by the clinical outcome data and the accessory genome patterns. Moreover, the transmission subclones circulated in two clinically important wards highlights the deficiency of infection control program using conventional methods. Without the assistance of whole-genome sequencing, the transmissions of high-risk clones could not be identified