Prediction of Abdominal Visceral Obesity From Body Mass Index,Waist Circumference and Waist-hip Ratio in Chinese Adults:Receiver Operating Characteristic Curves Analysis

Objective To evaluate the sensitivity and specificity of body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) measurements in diagnosing abdominal visceral obesity. Methods BMI, WC, and WHR were assessed in 690 Chinese adults (305 men and 385 women) and compared with magnetic resonance imaging (MRI) measurements of abdominal visceral adipose tissue (VA). Receiver operating characteristic (ROC) curves were generated and used to determine the threshold point for each anthropometric parameter. Results 1) MRI showed that 61.7% of overweight/obese individuals (BMI≥25 kg/m2) and 14.2% of normal weight (BMI<25 kg/m2) individuals had abdominal visceral obesity (VA≥100 cm2). 2) VA was positively correlated with each anthropometric variable, of which WC showed the highest correlation (r=0.73-0.77, P<0.001). 3) The best cut-off points for assessing abdominal visceral obesity were as followed: BMI of 26 kg/m2, WC of 90 cm, and WHR of 0.93, with WC being the most sensitive and specific factor. 4) Among subjects with BMI≥28 kg/m2 or WC≥95 cm, 95% of men and 90% of women appeared to have abdominal visceral obesity. Conclusion Measurements of BMI, WC, and WHR can be used in the prediction of abdominal visceral obesity, of which WC was the one with better accuracy.

Using receiver operating characteristic curves to evaluate the diagnostic value of the combination of multislice spiral CT and alpha-fetoprotein levels for small hepatocellular carcinoma in cirrhotic patients

BACKGROUND： The various combination of multiphase enhancement multislice spiral CT （MSCT） makes the diagno- sis of a small hepatocellular carcinoma （sHCC） on the back- ground of liver cirrhosis possible. This study was to explore whether the combination of MSCT enhancement scan and alpha-fetoprotein （AFP） level ficiency for sHCC. could increase the diagnostic ef- METHODS： This study included 35 sHCC patients and 52 cir- rhotic patients without image evidence of HCC as a control group. The diagnoses were made by three radiologists em- ploying a 5-point rating scale, with postoperative pathologic results as the gold standard. Receiver operating characteristic （ROC） curve analysis was performed to evaluate the diag- nostic value of the three MSCT combination modes （arterial phase＋portal-venous phase, arterial phase＋delayed phase, arterial phase＋portal-venous phase＋delayed phase） and AFP levels for sHCC on the background of liver cirrhosis. RESULTS： The area under ROC curve （AUC）, sensitivity, and specificity of the combination of arterial phase＋portal- venous phase＋delayed phase were 0.93, 93%, and 82%, respectively. The average AUC of the arterial phase＋portal- venous phase＋delayed phase combination was significantly greater than that of the arterial phase＋portal-venous phase （AUC=0.84, P=0.01） and arterial phase＋delayed phase （AUC=0.85, P=0.03）. Arterial phase＋portal-venous phase had a smaller AUC （0.84） than arterial phase＋delayed phase （0.85）, but the difference was insignificant （P=0.15）. After combining MSCT enhancement scan with AFP, the AUC, sensitivity, and specificity were 0.95, 94%, and 83%, respectively, indicating a greatly increased diagnostic efficiency for sHCC. CONCLUSIONS： The combination of AFP and 3 phases MSCT enhancement scan could increase the diagnostic efficiency for sHCC on the background of liver cirrhosis. The application of ROC curve analysis has provided a new method and reference in HCC diagnosis.

Determining endemic values of cutaneous leishmaniasis in Iranian Fars province by retrospectively detected clusters and receiver operating characteristic curve analysis

Objective: To determine the endemic values of cutaneous leishmaniasis in different cities of Fars province, Iran. Methods: Totally, 29 201 cases registered from 2010 to 2015 in Iranian Fars province were selected, and the endemic values of cutaneous leishmaniasis were determined by retrospective clusters derived from spatiotemporal permutation modeling on a time-series design. The accuracy of the values was assessed using receiver operating characteristic(ROC) curve. SPSS version 22, Arc GIS, and ITSM 2002 software tools were used for analysis. Results: Nine statistically significant retrospective clusters(P<0.05) resulted in finding seven significant and accurate endemic values(P<0.1). These valid endemic scores were generalized to the other 18 cities based on 6 different climates in the province. Conclusions: Retrospectively detected clusters with the help of ROC curve analysis could help determine cutaneous leishmaniasis endemic values which are essential for future prediction and prevention policies in the area.

Determination of the diagnostic value of the resazurin reduction assay for evaluating boar semen by receiver operating characteristic analysis

Aim： To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods： The accuracy of the spectrophotometric application of the resazurin reduction assay was assessed using receiver operating characteristic （ROC） analysis. Results： Areas under ROC curves （AUC） for motile sperm concentration and sperm index （SI） （sperm concentration multiplied by the square root of percentage sperm motility multiplied by the percentage normal sperm morphology） were 0.922. The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A610 = 0.209, where high sensitivity （94.1%） and specificity （91.7%） were calculated. The assay was less accurate when motile sperm concentration was used as the criterion value, yielding sensitivity of 88.2% and specificity of 87.5%, respectively. Likelihood ratios （LR） indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI, whereas in the case of motile sperm concentration, the LR was calculated to be 7.06. Conclusion： These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.

Preliminary Receiver Operating Characteristic Analysis on Voice Handicap Index of Laryngeal Inflammation in Greek Patients

Objective(s): Laryngeal inflammations lead to voice disorders. Medical conditions such as chronic laryngitis, gastroesophageal reflux, laryngopharyngeal reflux, Reinke edema and/or vocal folds hemorrhage, result in diverse symptoms including chronic cough, throat cleaning and dysphonia (e.g. hoarseness). In turn, the dysphonic symptoms can be evaluated via subjective and objective procedures. The objective procedures usually include self-perceived questionnaires like the Voice Handicap Index (VHI). Studies reported that VHI can distinguish objectively dysphonic and non-dysphonic populations using the cut-off points of Receiver Operating Characteristic Curves. The purpose of this study was to calculate the cut-off points for individuals exhibiting voice symptoms which had been developed from laryngeal inflammatory diseases in Greece. Methods: One hundred and twelve participants (90 non-dysphonic and 22 dysphonic) filled in the Hellenic Voice Handicap Index (VHI) and the Greek translated version of Voice Evaluation Template (VEF) were administrated. All subjects were evaluated by an Otolaryngologist and a Speech-Language Pathologist. Results: The group with voice disorders exhibited higher VHI scores (in total and in its 3 subdomains) compared to non-dysphonic subgroup. Statistical significant differences were found for all VHI’s total cut-off point of 19.50 (sensitivity: 0.882, 1-specificity: 0.011) and for its three subdomains [functional 6.50 (sensitivity = 0.636, and 1-specificity = 0.022);physical 9.50 (sensitivity = 0.636, and 1-specificity = 0.000);emotional 6.50 (sensitivity = 0.455, and 1-specificity = 0.133)]. Conclusion: The preliminary results showed that VHI could discriminate individuals having voice disorders from laryngeal inflammations. The Voice Handicap Index can be used as a primary health care tool and a self-monitoring procedure in acute and sub-acute phases of the laryngeal inflammation.

Determination of the diagnostic value of the resazurin reduction assay for evaluating boar semen by receiver operating cha-racteristic analysis

Aim:To assess that metabolic status of spermatozoa could provide a useful tool for evaluation of semen quality. Methods:The accuracy of the spectrophotometric application of the resazurm reduction assay was assessed using receiver operating characteristic(ROC)analysis.Results:Areas under ROC curves(AUC)for motile sperm concen- tration and sperm index(SI)(sperm concentration multiplied by the square root of percentage sperm motility multi- plied by the percentage normal sperm morphology)were 0.922.The best discrimination between poor and good semen samples according to the SI was achieved at a cut-off point of A_(610)=0.209,where high sensitivity(94.1%)and specificity(91.7%)were calculated.The assay was less accurate when motile sperm concentration was used as the criterion value,vielding sensitivity of 88.2% and specificity of 87.5%,respectively,Likelihood ratios(LR)indicate that absorbances lower than 0.209 were at least 11.3 times as likely to be found in good semen samples than those in poor according to the SI,whereas in the case of motile sperm concentration,the LR was calculated to be 7.06.Conclusion: These results show that the resazurin reduction assay combined with spectrophotometry is an accurate method of assessing the quality of boar semen.

Nomogram for predicting lymph node metastasis rate of submucosal gastric cancer by analyzing clinicopathological characteristics associated with lymph node metastasis

Background： To combine dinicopathological characteristics associated with lymph node metastasis for submucosal gastric cancer into a nomogram. Methods： We retrospectively analyzed 262 patients with submucosal gastric cancer who underwent D2 gastrectomy between 1996 and 2012. The relationship between lymph node metastasis and clinicopathological features was statistically analyzed. With multivariate logistic regression analysis, we made a nomogram to predict the possibility of lymph node metastasis. Receiver operating characteristic （ROC） analysis was also performed to assess the predictive value of the model. Discrimination and calibration were performed using internal validation. Results： A total number of 48 （18.3%） patients with submucosal gastric cancer have pathologically lymph node metastasis. For submucosal gastric carcinoma, lymph node metastasis was associated with age, tumor location, macroscopic type, size, differentiation, histology, the existence of ulcer and lymphovascular invasion in univariate analysis （all P〈0.05）. The multivariate logistic old, macroscopic type III or mixed, undifferentiated type, regression analysis identified that age _〈50 years and presence of lymphovascular invasion were independent risk factors of lymph node metastasis in submucosal gastric cancer （all P〈0.05）. We constructed a predicting nomogram with all these factors for lymph node metastasis in submucosal gastric cancer with good discrimination [area under the curve （AUC） =0.844]. Internal validation demonstrated a good discrimination power that the actual probability corresponds closely with the predicted probability. Conclusions： We developed a nomogram to predict the rate of lymph node metastasis for submucosal gastric cancer. With good discrimination and internal validation, the nomogram improved individualized predictions for assisting clinicians to make appropriated treatment decision for submucosal gastric cancer patients.

Receiver operating characteristic curve analysis for image quality in the detection of solitary pulmonary nodules on high resolution paper prints versus dry laser film

Along with the development of digital X-ray imaging technology, a new, economical and practicalpaper-based output system gradually emerged. To reduce cost, more and more radiologic institutions began to change from film copies to lower-priced paper prints for documenting radiologic findings.Therefore, laser paper printers are frequently used as an alternative to duplicating film though the use of printed images is not yet widespread. The aim of this study was to compare the practical value of high-resolution paper printer with dry film copies for detecting small solitary pulmonary nodules （SPNs）.

Study on Diagnosis Criteria of Fire-Heat Syndrome Based on Receiver Operating Characteristic Curve and Principal Component Analysis

Objective： To establish the diagnostic quantitative criteria for fire-heat syndrome （FHS） of Chinese medicine （CM） based on the receiver operating characteristic （ROC） curve and principal component analysis （PCA）. Methods： The symptoms and signs of FHS cases and healthy subjects from Guangzhou, Henan and Hunan of China were collected through questionnaire, and the diagnostic quantitative score tables were established for the three regions, respectively, with the method of maximum likelihood analysis. The homogeneity test was then performed on the diagnostic score tables for the three regions with ROC curve, and the diagnostic efficiency of diagnostic score tables for the three regions was compared with the prospective test and retrospective test. The method of PCA was adopted to obtain the analysis matrix for classifying the tapes of FHS. Results： Twenty-seven elements of FHS were confirmed through Chi-square test, and the diagnostic score tables for the three regions were established with the method of maximum likelihood analysis on the basis of the collected case data. According to the ROC curve test, the areas under ROC curve of Guangzhou diagnostic score table assessment with candidates in Guangzhou, Henan and Hunan were 0.998, 0.961 and 0.956, respectively. It showed that the diagnostic efficiency of Guangzhou diagnostic score tables was the highest one. With the prospective test, the area under ROC of Guangzhou diagnostic score table was 0.949, and more than any other diagnostic score table. By PCA, FHS was classified into excess fire and deficiency fire, and then classified into syndrome of flaring up of Heart （Xin） fire, syndrome of Lung （Fei）-Stomach （Wei） excess fire, syndrome of deficiency of Liver （Gan）-yin and Kidney （Shen）-yin, and syndrome of deficiency of Lung-yin from the view of viscera. In the retrospective test, the consistency with clinicians＇ diagnosis was 69.4%, and in the prospective test, it was 70.1%. Conclusions： The Guangzhou diagnostic score table could be used as the recommended criteria for the diagnosis of FHS. The classification of FHS was basically in conformity with the clinical situation.

Optimizing Operating Cost of an Intrusion Detection System

Very often it so happens that the cost of operating an Intrusion Detection System (IDS) exceeds the cost of purchasing the IDS itself. In such cases, regular operation and maintenance of the system becomes expensive. Thus, it becomes essential to reduce the operating cost of the IDS without compromising on the performance and reliability of the IDS. Apart from the initial cost of procuring the IDS, other costs include cost of accessories required and cost of administration etc. In this paper we calculate the cost benefit tradeoffs of an IDS. We propose a method to determine the optimum operating point of the IDS. In an effort to solve the problems of the previously proposed metrics, we propose a decision tree based approach to calculate the cost of operating an IDS in a mobile ad hoc network. Mathematically and programmatically we deduce the minimum operating point of operation of an IDS and generate the receiver operating characteristic curve of the IDS. To further ascertain this, we use available network packet capture data and calculate the minimum operating cost of an IDS. The main motive behind this paper is to show that the cost of operating an IDS in a MANET can be minimized and hence the effectiveness and performance of the IDS can be maximized.

基于ROC模型预测老年急性胆囊炎患者发生术后感染风险的临床研究

目的:探讨基于受试者工作特征曲线(Receiver operating characteristic,ROC)诊断模型预测老年急性胆囊炎患者发生术后临床感染的风险因素。方法:将我院2023年01月20至2024年02月诊治的114例老年急性胆囊炎患者作为研究对象,按照患者发生术后感染的情况将患者分为感染组46例,未感染组68例。分析两组患者发生术后感染发生风险因素的单因素,采用多因素Logistic回归分析评估患者发生术后感染的风险因素。采用ROC曲线预测老年急性胆囊炎患者发生术后感染的临床风险因素。结果:感染组中≥70岁、糖尿病、肝硬化、胆囊周边积液、胆囊结石、白细胞计数>10×10^(9)·L^(-1)者占比均高于未感染组。经多因素Logistic回归分析,上述单因素风险因素为术后感染的风险因素(P<0.05)。ROC曲线分析显示,年龄≥70岁、糖尿病、肝硬化、胆囊周边积液、胆囊结石、白细胞计数>10×10^(9)·L^(-1)对患者发生术后感染风险有较高的预测价值(AUC>0.70)。结论:年龄≥70岁、糖尿病、胆囊周边积液、肝硬化、胆囊结石、白细胞计数>10×10^(9)·L^(-1)因素均可能导致老年急性胆囊炎患者发生术后感染的临床风险指标。

基于ROC曲线的几种创伤严重程度评估工具对老年创伤患者院内死亡预测效果的对比研究

目的比较新损伤严重程度评分(NISS)、指数型损伤严重程度评分(EISS)、创伤和损伤严重程度评分(TRISS)及老年创伤结局评分(GTOS)用于预测老年创伤患者院内死亡风险的效果。方法回顾性追溯选定时间跨度(2019年1月至2022年12月)内所有经急诊入院的老年创伤患者(共197例)的临床资料,计算并统计上述4种创伤严重程度评估工具的结果并绘制受试者工作特征(ROC)曲线,分析比较各评估工具的ROC曲线下面积(AUC)、约登指数以及敏感度、特异度,并以传统的损伤严重程度评分(ISS)的结果作为对照。结果4种改进型评估工具的预测效果均优于传统评估工具(ISS评分)。其中,TRISS评分的AUC、约登指数、敏感度和特异度均最高;NISS评分的AUC和约登指数均最低;GTOS评分的AUC和敏感度与EISS评分较为接近,但约登指数和特异度均显著高于EISS评分。结论TRISS评分在急诊老年创伤患者死亡风险预测评估方面的综合应用效果最佳,GTOS评分预测效果不及TRISS,但评估计算过程更简单,其改进和优化值得进一步探索。

应用ROC曲线评价N末端B型脑钠肽(NT-proBNP)及生化指标在心血管疾病中的诊断价值

目的评价N末端B型脑钠肽(NT-proBNP)、同型半胱氨酸(Hcy)、超敏肌钙蛋白T(cTnT)、肌钙蛋白I(cTnI)及其他生化项目对心血管疾病的诊断价值。方法应用受试者工作特征曲线(ROC)对131例心血管疾病患者、43例单纯性高血压患者和61例健康对照者的血清NT-proBNP、Hcy及cTnT、cTnI及其他生化指标进行分析,并对心血管疾病组患者NT-proB-NP与心功能分级进行相关性研究。结果 NT-proBNP、Hcy、cTnT、cTnI、CK-MB的水平在心血管病组和对照组两组间差异有统计学意义(P<0.05);NT-proBNP、cTnT、cTnI、CK-MB在心血管病组和高血压病组间存在统计学差异(P<0.05)。急性心肌梗死、风湿性心脏病、肺源性心脏病、心肌炎病患者血清NT-proBNP水平显著高于心绞痛、先天性心脏病、心律不齐等其他心血管病患者。NT-proBNP、cTnT、cTnI、CK-MB的ROC曲线下面积(AUC)分别为0.767,0.745,0.734,0.715。心血管病患者血清NT-proBNP、cTnT、cTnI、CK-MB水平与心血管病患者心功能分级间呈显著正相关,相关系数分别为0.912,0.891,0.816,0.718,均P<0.05。结论 NT-proBNP、cTnT、cTnI、CK-MB是临床诊断心血管疾病的有价值指标。

Logistic回归及ROC曲线综合评价CA15-3、CA125、CK19、CEA、AFP和CA199在乳腺癌术后监测中的应用价值

目的:应用Logistic回归模型及受试者工作特征曲线(Receiver operating characteristic curve,ROC曲线)探讨多种血清肿瘤标志物在乳腺癌术后监测中的应用价值。方法:采用化学发光免疫分析法测定34例术后复发转移患者及76例无复发患者的血清CA15-3、CA125、CK19、CEA、AFP、CA199水平,通过组间均值比较和Logistic逐步回归分析筛选出有效指标,并通过ROC曲线评价其在术后复发转移判断中的诊断价值。结果:其中3项血清肿瘤标志物CA15-3、CK19和CEA入选Logistic回归方程,对应的曲线下面积分别为0.974、0.922、0.913,阳性检出率分别为82.4%、73.5%和64.7%。结论:肿瘤标志物CA15-3、CK19、CEA在术后复发或转移诊断中有较高的应用价值,可作为乳腺癌术后监测复发转移的有效指标。

基于ROC曲线的弹道目标识别评估及优化

分析了弹道目标识别的特点,指出弹道真假目标识别在本质上是一个风险最小的寻优过程,等同于Neyman-Pearson决策。在此基础上,提出采用ROC曲线下的面积(AUC)对识别方法进行评估,介绍了AUC的两种计算方法。进一步,提出采用AUC对识别器进行比较及优化,介绍了ROC凸包的基本概念并将其用于识别器优化。进行了相应的仿真实验,结果表明了所提出方法的可行性。

SPSS中的ROC分析用于检验/诊断方法的评价

[目的 ]介绍如何用SPSS软件包中新颖的ROC分析法 ,来对一种或几种检验 /诊断方法进行科学评价。[方法 ]回顾目前文献中的存在问题 ;对四格表排列、数据库录入以及ROC命令默认设置提出应用或改变建议 ;举例说明定性、定量资料的ROC分析方法 ;介绍 2或 3种诊断方法诊断效能比较的ROC分析方法与结果 ;ROC分析结果与列联表分析、logistic回归及判别分析结果相印证。[结果 ]按本文建议 ,ROC分析能方便地对一种或几种检验 /诊断方法进行科学评价 ,算出其敏感性与特异性等 6项指标 ,且与其他 3种分析方法统一、对应。 [结论 ]ROC曲线能将诊断方法的敏感性与特异性结合起来进行分析 ,而不是仅侧重于其敏感性或特异性 ,又能表示为“曲线下的面积越大 ,其诊断试验效果越好” ,既全面又直观 ,又与其他统计分析方法结果对应、统一 ,值得在检验

ROC曲线在临床医学诊断实验中的应用

随着先进医学技术的迅猛发展，各种新诊断试验层出不穷，但并不是每一种新诊断试验肯定比旧试验好。如果医学工作者，特别是临床医生，能够掌握一些评价与解释诊断试验的有关知识，及时取舍或灵活运用新的诊断试验，可以更好地为患者服务。为了进一步推广receiver operating characteristic（ROC）曲线分析方法的应用，本文首先介绍诊断实验的相关慨念，ROC曲线分析的定义、原理及分类，ROC曲线曲线下面积（AUC）及其最佳工作点的确定，然后用SPSS软件具体说明其应用。

ROC曲线评价二维超声与彩色多普勒诊断小乳腺癌

目的评价二维超声与彩色多普勒超声在小乳腺癌诊断中的价值。方法分别采用二维超声及其结合彩色多普勒对134个乳腺小瘤灶(≤2cm)的图像资料进行分析,评价其良恶性,并以手术病理诊断为金标准进行分析。结果二维超声及其结合彩色多普勒超声诊断小乳腺癌的ROC曲线下面积分别为0.705(SE1=0.045)和0.844(SE2=0.035),两者差异有统计学意义(Z=2.438,P<0.001)。结论二维声像图是发现小乳腺癌的主要方法;与彩色多普勒超声联合应用、综合判断,可以提高小乳腺癌诊断水平,具有重要的临床应用价值。

影像学诊断评价中的参数法ROC曲线分析

目的探讨采用ROC曲线参数分析法对影像学分类诊断结果进行评价的价值,并介绍ROC曲线参数分析软件ROCKIT。方法 2名医师分别对60幅肺部CT图像进行肺结节良恶性5级分类诊断。分别用ROCKIT软件和SPSS软件对他们的诊断结果进行参数法和非参数法ROC曲线分析。结果对2名医师的诊断结果利用ROCKIT进行参数法ROC分析时,ROC曲线下面积分别为0.940±0.039和0.785±0.075(Z=2.056,P=0.040),利用SPSS进行非参数估计时结果分别为0.913±0.042和0.771±0.075。通过ROCKIT软件可绘制光滑的拟合ROC曲线,SPSS软件可绘制不光滑的经验ROC曲线。结论当有序分类资料样本量适中时,参数估计一般均无偏倚,非参数估计的结果可能小于真实值;ROCKIT软件是双正态参数法ROC曲线分析的有力工具。

CT预测肝硬化门静脉高压并发上消化道出血风险的ROC分析

目的研究肝硬化门静脉高压侧支循环相关血管的CT征象以及预测上消化道出血的临界点、敏感性、特异性。资料与方法肝硬化门静脉高压并发消化道出血患者30例为A组,未出血患者30例为B组。CT检测胃冠状静脉(GCV)直径,胃底-脾门区域静脉血管截面数量及总面积,计算敏感性、特异性,并选择约登指数(Youdenin-dex)最高的临界点。结果A组GCV直径为(7·62±2.07)mm;B组为(5.57±1.43)mm,临界点为6.5mm,约登指数为0·43。A组胃底-脾门区域静脉血管数量为(4.35±1.50)支;B组为(3.10±0.75)支,临界点为4支,约登指数为0·38。A组静脉血管面积为(2.52±2.04)cm2;B组为(0.95±0.50)cm2,将临界点设定为1.10cm2时,约登指数为0·60;临界点设为1.50cm2时,约登指数为0·71。结论曲线下面积(AUGROC)从高到低的是胃底-脾门区域静脉血管截面总面积(0·92),GCV直径(0·80),胃底-脾门区域静脉血管截面数量(0·75),胃底-脾门区域静脉血管截面总面积作为一种新的预测出血的CT检测指标具有较高价值。