Evaluation of the diagnostic performance of a decision tree model in suspected acute appendicitis with equivocal preoperative computed tomography findings compared with Alvarado, Eskelinen, and adult appendicitis scores: A STARD compliant article.

This study evaluated the diagnostic performance of a new clinical approach based on decision tree (DT) analysis in adult patients with equivocal computed tomography (CT) findings of acute appendicitis (AA) compared with previous scoring systems.This retrospective study of 244 adult patients with equivocal CT findings included appendicitis (AG, n = 80) and non-appendicitis (NAG, n = 164) groups. The chi-squared automatic interaction detection algorithm was for AA prediction. A receiver operating characteristic curve analysis and area under the curve (AUC) were used to compare the DT analysis with Alvarado, Eskelinen score, and adult appendicitis scores (AAS).The following factors were selected for AA prediction: rebound tenderness severity, migration, urinalysis, symptom duration, leukocytosis, neutrophil count, and C-reactive protein levels. The DT comprised 11 final nodes with the following AA probabilities: node 1, 100% (16/16); node 2, 90% (9/10); node 3, 80% (8/10); node 4, 60.9% (14/23); node 5, 50% (3/6); node 6, 43.8% (7/16); node 7, 22.6% (12/53); node 8, 13% (10/77); node 9, 5.6% (1/18); node 10, 0% (0/12); and node 11, 0% (0/3). The AUC of the DT was higher (0.850 [95% confidence interval {CI}; 0.799-0.893]) than the Alvarado score (0.695 [95% CI; 0.633-0.752]), AAS (0.749 [95% CI; 0.690-0.802]), and the Eskelinen score (0.715 [95% CI; 0.654-0.770]). The results were statistically significant when compared with the AUCs of the Alvarado score, Eskelinen score, and AAS (P < .001, P < .001, P = .003, respectively).The DT-based approach facilitated AA diagnosis and determination of clinical status in patients with equivocal preoperative CT findings and ambiguous results.

Can clinical scoring systems improve the diagnostic accuracy in patients with suspected adult appendicitis and equivocal preoperative computed tomography findings?

OBJECTIVE: Adult appendicitis (AA) with equivocal computed tomography (CT) findings remains a diagnostic challenge for physicians. Herein we evaluated the diagnostic performance of several clinical scoring systems in adult patients with suspected appendicitis and equivocal CT findings. METHODS: We retrospectively evaluated 189 adult patients with equivocal CT findings. Alvarado, Eskelinen, appendicitis inflammatory response, Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA), and adult appendicitis score (AAS) scores were evaluated, receiver operating characteristic analysis was conducted, and the optimal, low, and high cut-off values were determined for patient classification into three groups: low, intermediate, or high. RESULTS: In total, 61 patients were included in the appendicitis group and 128 in the non-appendicitis group. There were no significant differences between the area under the curve of the clinical scoring systems in the final diagnosis of AA for equivocal appendicitis on CT (Alvarado, 0.698; Eskelinen, 0.710; appendicitis inflammatory response, 0.668; RIPASA, 0.653; AAS, 0.726). A RIPASA score greater than 7.5 had a high positive predictive value (90.9) and an AAS score less than or equal to 5 had a high negative predictive value (91.7) in the diagnosis of AA. CONCLUSION: The accuracy of clinical scoring systems in the diagnosis of AA with equivocal CT findings was moderate. Therefore, a high RIPASA score may assist in the diagnosis of AA in patients with equivocal CT findings, and a low AAS score may be used as a criterion for patient discharge. Most patients presented with intermediate scores. The patients with equivocal CT findings may be considered as a third diagnostic category of AA.

Effects of physicochemical surface characteristics of Listeria monocytogenes strains on attachment to glass.

Seven strains of Listeria monocytogenes frequently involved in foodborne disease (epidemic strains) and 14 sporadic strains were examined to compare the attachment and subsequent biofilm growth on glass slides at 37 degrees C. Epidemic strains at 3 h incubation had significantly higher attachment values than sporadic strains (P<0.001), but subsequent biofilm growth over 24 h was not dependent on initial attachment. To better understand this phenomenon, the surface hydrophobicity and charge, as well as the extracellular carbohydrate content of the 21 L. monocytogenes strains were studied to determine if these surface characteristics had an effect on bacterial attachment to glass. Hydrophobicity was measured by the bacterial adherence to hydrocarbon (BATH) and polystyrene adherence methods. Hydrophobicity values obtained with the BATH method were linearly correlated with those from the polystyrene adherence method (r=0.64, P<0.001), but no correlation was found between hydrophobicity and bacterial attachment to glass. Hydrophobicity and surface charge measured as electrophoretic mobility (EM) were correlated (r=0.77, P<0.001); however, there was no correlation between the degree of attachment and surface charge. Colorimetric measurements of the total extracellular carbohydrates revealed that attached cells produced significantly (P<0.05) higher levels than planktonic cells after a 3 h time period. Analysis of co-variance (Nested ANCOVA) furthermore demonstrated that total carbohydrates produced by planktonic cells had a significant positive effect on 24 h biofilm growth (P=0.006). This is the first report to indicate that the ability of a L. monocytogenes strain to produce high levels of extracellular carbohydrates may increase its ability to form a biofilm. Genetic studies targeting carbohydrate synthesis pathways of L. monocytogenes will be required to fully understand the importance of this observation.