A hybrid decision support model to discover informative knowledge in diagnosing acute appendicitis

BACKGROUND: The aim of this study is to develop a simple and reliable hybrid decision support model by combining statistical analysis and decision tree algorithms to ensure high accuracy of early diagnosis in patients with suspected acute appendicitis and to identify useful decision rules. METHODS: We enrolled 326 patients who attended an emergency medical center complaining mainly of acute abdominal pain. Statistical analysis approaches were used as a feature selection process in the design of decision support models, including the Chi-square test, Fisher's exact test, the Mann-Whitney U-test (p < 0.01), and Wald forward logistic regression (entry and removal criteria of 0.01 and 0.05, or 0.05 and 0.10, respectively). The final decision support models were constructed using the C5.0 decision tree algorithm of Clementine 12.0 after pre-processing. RESULTS: Of 55 variables, two subsets were found to be indispensable for early diagnostic knowledge discovery in acute appendicitis. The two subsets were as follows: (1) lymphocytes, urine glucose, total bilirubin, total amylase, chloride, red blood cell, neutrophils, eosinophils, white blood cell, complaints, basophils, glucose, monocytes, activated partial thromboplastin time, urine ketone, and direct bilirubin in the univariate analysis-based model; and (2) neutrophils, complaints, total bilirubin, urine glucose, and lipase in the multivariate analysis-based model. The experimental results showed that the model with univariate analysis (80.2%, 82.4%, 78.3%, 76.8%, 83.5%, and 80.3%) outperformed models using multivariate analysis (71.6%, 69.3%, 73.7%, 69.7%, 73.3%, and 71.5% with entry and removal criteria of 0.01 and 0.05; 73.5%, 66.0%, 80.0%, 74.3%, 72.9%, and 73.0% with entry and removal criteria of 0.05 and 0.10) in terms of accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and area under ROC curve, during a 10-fold cross validation. A statistically significant difference was detected in the pairwise comparison of ROC curves (p < 0.01, 95% CI, 3.13-14.5; p < 0.05, 95% CI, 1.54-13.1). The larger induced decision model was more effective for identifying acute appendicitis in patients with acute abdominal pain, whereas the smaller induced decision tree was less accurate with the test data. CONCLUSIONS: The decision model developed in this study can be applied as an aid in the initial decision making of clinicians to increase vigilance in cases of suspected acute appendicitis

The Incidence of Gastro-Esophageal Disease for the Patients with Typical Chest Pain and a Normal Coronary Angiogram

Background : Although patients may present with typical chest pain and exhibit ischemic changes on the cardiac stress test, they are frequently found to have a normal coronary angiogram. Thus, we wanted to determine which procedures should be performed in order to make an adequate diagnosis of the cause of chest pain. Methods : 121 patients (males: 42, 34.7%) who had a normal coronary angiogram with typical chest pain were included in this study. All the patients underwent upper endoscopy, Bernstein&apos;s test and esophageal manometry. Results : Among the 121 patients, clinically stable angina was noted in 107 (88.4%). Stress testing was done in 82 (67.8%); it was positive in 52 (63.4%). Endoscopic findings were erosive gastritis in 18 (14.8%), gastric ulcer in 4 (3.3%), duodenal ulcer in 5 (4.1%), and reflux esophagitis in 16 (13.2%). Positive results were observed on Berstein&apos;s test for 68 patients (56.2%); 59 (86.8%) of them had non-erosive reflux disease. On the esophageal manometry, 35 (28.9%) of these patients had motility disorders. Nutcracker esophagus was observed in 27 patients (22.3%), nonspecific esophageal motility disorder was observed in 5 (4.1%), and hypertensive lower esophageal sphincter was observed in 3 (2.5%). Among the 52 patients with positive cardiac stress testing and a negative coronary angiogram (this clinically corresponded to microvascular angina), 46 patients (85.1%) showed abnormal findings on the gastro-esophageal studies. Conclusions : In our study, 85.1% of the patients with microvascular angina revealed positive results of gastric or esophageal disease. In spite of any existing evidence of microvascular angina or cardiac syndrome X, it would be more advisable to perform gastro-esophageal studies to adequately manage chest pain

Is the Environment of the Endoscopy Unit a Reservoir of Pathogens?

Background/AimsGiven the characteristic procedures involved in the endoscopy unit, the spread of pathogens is much more frequent in this unit than in other environments. However, there is a lack of data elucidating the existence of pathogens in the endoscopy unit. The aim of this study was to detect the presence of possible pathogens in the endoscopy unit.MethodsWe performed environmental culture using samples from the endoscopy rooms of 2 tertiary hospitals. We used sterile cotton-tipped swabs moistened with sterile saline to swab the surfaces of 197 samples. Then, we cultured the swab in blood agar plate. Samples from the colonoscopy room were placed in thioglycollate broth to detect the presence of anaerobes. After 2 weeks of culture period, we counted the colony numbers.ResultsThe most commonly contaminated spots were the doctor's keyboard, nurse's cart, and nurse's mouse. The common organisms found were non-pathogenic bacterial microorganisms Staphylococcus, Micrococcus, and Streptococcus spp.. No definite anaerobe organism was detected in the colonoscopy room.ConclusionsAlthough the organisms detected in the endoscopy unit were mainly non-pathogenic organisms, they might cause opportunistic infections in immunocompromised patients. Therefore, the environment of the endoscopy room should be managed appropriately; moreover, individual hand hygiene is important for preventing possible hospital-acquired infections

Survival outcomes of hepatic resection compared with transarterial chemoembolization or sorafenib for hepatocellular carcinoma with portal vein tumor thrombosis

Background/Aims:Treating hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) remains controversial. We compared the outcomes of hepatic resection (HR), transarterial chemoembolization (TACE), and sorafenib therapy as treatments for HCC with PVTT. Methods:Patients diagnosed as HCC with PVTT between January 2000 and December 2011 who received treatment with sorafenib, HR, or TACE were included. Patients with main PVTT, superior mesenteric vein tumor thrombosis, or Child-Turcotte-Pugh (CTP) class C were excluded. The records of 172 patients were analyzed retrospectively. HR, TACE, and sorafenib treatment were performed is 40, 80, and 52 patients respectively. PVTT was classified as either involving the segmental branch (type I) or extending to involve the right or left portal vein (type II). Results:The median survival time was significantly longer in the HR group (19.9 months) than in the TACE and sorafenib groups (6.6 and 6.2 months, respectively; both p<0.001), and did not differ significantly between the latter two groups (p=0.698). Among patients with CTP class A, type I PVTT or unilobar-involved HCC, the median survival time was longer in the HR group than in the TACE and sorafenib groups (p=0.006). In univariate analyses, the initial treatment method, tumor size, PVTT type, involved lobe, CTP class, and presence of cirrhosis or ascites were correlated with overall survival. The significant prognostic factors for overall survival in Cox proportional-hazards regression analysis were initial treatment method (HR vs. TACE: hazard ratio=1.750, p=0.036; HR vs. sorafenib: hazard ratio=2.262, p=0.006), involved lobe (hazard ratio=1.705, p=0.008), PVTT type (hazard ratio=1.617, p=0.013), and CTP class (hazard ratio=1.712, p=0.012). Conclusions:Compared with TACE or sorafenib, HR may prolong the survival of patients with HCC in cases of CTP class A, type I PVTT or unilobar-involved HCC