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 wer...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.展开更多
在数据挖掘领域中,不同分类器建立的模型性能不尽相同。对分类器性能的评价是选择优秀分类器的基础。为了更好地对分类器性能进行评估,文中对分类器性能评价标准进行了研究。分析了传统分类器性能评价标准在应用时存在的一些问题,重点...在数据挖掘领域中,不同分类器建立的模型性能不尽相同。对分类器性能的评价是选择优秀分类器的基础。为了更好地对分类器性能进行评估,文中对分类器性能评价标准进行了研究。分析了传统分类器性能评价标准在应用时存在的一些问题,重点介绍了ROC曲线(the Receiver Operating Characteristic curve)和AUC(the area under the ROC curve)评价方法,并剖析了它们的优缺点。对比分析表明,ROC曲线和AUC方法虽然存在着一定的不足,但是在分类器性能评价中所表现出的诱人性质使其必定具有广阔的应用前景。展开更多
BACKGROUND: The differential diagnosis of solid lesions located at the pancreatic head is very important for choosing therapies and setting up surgical tactics. This study was designed to evaluate the clinical signifi...BACKGROUND: The differential diagnosis of solid lesions located at the pancreatic head is very important for choosing therapies and setting up surgical tactics. This study was designed to evaluate the clinical significance of combined measurement of multiple serum tumor markers and the application of the receiver-operating characteristic (ROC) curves in the differential diagnosis of solid lesions located at the pancreatic head. METHODS: The serum levels of CA19-9, CA242, CA50 and carcinoembryonic antigen (CEA) in 112 patients with carcinoma of the pancreatic head and 38 patients with focal chronic pancreatitis in the pancreatic head were measured with ELISA. The sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) of the four serum tumor markers were calculated. The ROC curves for the four serum tumor markers were constructed and the area under the curve (AUC) was calculated. RESULTS: The AUCs of CA19-9, CA242, CA50 and CEA were 0.805, 0.749, 0.738 and 0.705; the PLRs were 1.91, 3.43, 5.09 and 5.46; and the NLRs were 0.41, 0.56, 0.59 and 0.71, respectively. Combined measurements increased the diagnostic specificity, and parallel combined testing increased the diagnostic sensitivity. CONCLUSIONS: Combined measurement of serum tumor markers CA19-9, CA242, CA50 and CEA is valuable in differential diagnosis of solid lesions located at the pancreatic head, and CA19-9 has the best diagnostic ability. Combined measurements can increase the specificity of diagnosis. Evaluation with the ROC curve is better than the sensitivity or specificity alone and the results are more integrated and objective.展开更多
AIM: To evaluate the clinical utility of serum fibrosis markers, including YKL-40, in patients with HCV-associated liver disease. METHODS: A total of 109 patients with HCV-associated liver disease were enrolled. We me...AIM: To evaluate the clinical utility of serum fibrosis markers, including YKL-40, in patients with HCV-associated liver disease. METHODS: A total of 109 patients with HCV-associated liver disease were enrolled. We measured serum type IV collagen, amino-terminal peptide of type III procollagen (PIIIP), hyaluronic acid (HA), YKL-40 levels and biochemical. Parameters by RIA or ELISA. Eighty-eight patients underwent liver biopsy, and 67 of 109 patients received interferon (IFN) therapy. We also investigated the relationship between the concentrations of serum fibrosis markers and histological fibrosis scores (METAVIR), and evaluated the changes of the levels of fibrosis markers before and after the IFN therapy. RESULTS: The increase in serum levels of all markers, particularly HA, was correlated with the progression of liver fibrosis (for type IV collagen, F= 9.076, P<0.0001; for PIIIP, F= 9.636, P<0.0001; for HA, F=13.128, P<0.0001; and for YKL-40, F= 8.016, P<0.0001). YKL-40 had strong correlation with HA (r= 0.536, P<0.0001). Based on the receiver operating curve (ROC), the ability of serum HA exceeded the abilities of other serum markers to determine fibrosis score 4 from fibrosis score 0-3 (AUC = 0.854). While YKL-40 was superior to other fibrosis markers for predicting severe fibrosis (F2-F4) from mild fibrosis (FO-F1) (YKL-40, AUC = 0.809; HA, AUC = 0.805). After IFN therapy, only YKL-40 values significantly decreased not only in the responder group, but also in the nonresponder group (P = 0.03). CONCLUSION: YKL-40 may be a useful non-invasive serum marker to estimate the degree of liver fibrosis and to evaluate the efficacy of IFN therapies in patients with HCV-associated liver disease.展开更多
文摘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.
文摘在数据挖掘领域中,不同分类器建立的模型性能不尽相同。对分类器性能的评价是选择优秀分类器的基础。为了更好地对分类器性能进行评估,文中对分类器性能评价标准进行了研究。分析了传统分类器性能评价标准在应用时存在的一些问题,重点介绍了ROC曲线(the Receiver Operating Characteristic curve)和AUC(the area under the ROC curve)评价方法,并剖析了它们的优缺点。对比分析表明,ROC曲线和AUC方法虽然存在着一定的不足,但是在分类器性能评价中所表现出的诱人性质使其必定具有广阔的应用前景。
基金This study was supported by a grant from Clinical Subject of Ministry of Health of China (2004-2006-2).
文摘BACKGROUND: The differential diagnosis of solid lesions located at the pancreatic head is very important for choosing therapies and setting up surgical tactics. This study was designed to evaluate the clinical significance of combined measurement of multiple serum tumor markers and the application of the receiver-operating characteristic (ROC) curves in the differential diagnosis of solid lesions located at the pancreatic head. METHODS: The serum levels of CA19-9, CA242, CA50 and carcinoembryonic antigen (CEA) in 112 patients with carcinoma of the pancreatic head and 38 patients with focal chronic pancreatitis in the pancreatic head were measured with ELISA. The sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) of the four serum tumor markers were calculated. The ROC curves for the four serum tumor markers were constructed and the area under the curve (AUC) was calculated. RESULTS: The AUCs of CA19-9, CA242, CA50 and CEA were 0.805, 0.749, 0.738 and 0.705; the PLRs were 1.91, 3.43, 5.09 and 5.46; and the NLRs were 0.41, 0.56, 0.59 and 0.71, respectively. Combined measurements increased the diagnostic specificity, and parallel combined testing increased the diagnostic sensitivity. CONCLUSIONS: Combined measurement of serum tumor markers CA19-9, CA242, CA50 and CEA is valuable in differential diagnosis of solid lesions located at the pancreatic head, and CA19-9 has the best diagnostic ability. Combined measurements can increase the specificity of diagnosis. Evaluation with the ROC curve is better than the sensitivity or specificity alone and the results are more integrated and objective.
文摘AIM: To evaluate the clinical utility of serum fibrosis markers, including YKL-40, in patients with HCV-associated liver disease. METHODS: A total of 109 patients with HCV-associated liver disease were enrolled. We measured serum type IV collagen, amino-terminal peptide of type III procollagen (PIIIP), hyaluronic acid (HA), YKL-40 levels and biochemical. Parameters by RIA or ELISA. Eighty-eight patients underwent liver biopsy, and 67 of 109 patients received interferon (IFN) therapy. We also investigated the relationship between the concentrations of serum fibrosis markers and histological fibrosis scores (METAVIR), and evaluated the changes of the levels of fibrosis markers before and after the IFN therapy. RESULTS: The increase in serum levels of all markers, particularly HA, was correlated with the progression of liver fibrosis (for type IV collagen, F= 9.076, P<0.0001; for PIIIP, F= 9.636, P<0.0001; for HA, F=13.128, P<0.0001; and for YKL-40, F= 8.016, P<0.0001). YKL-40 had strong correlation with HA (r= 0.536, P<0.0001). Based on the receiver operating curve (ROC), the ability of serum HA exceeded the abilities of other serum markers to determine fibrosis score 4 from fibrosis score 0-3 (AUC = 0.854). While YKL-40 was superior to other fibrosis markers for predicting severe fibrosis (F2-F4) from mild fibrosis (FO-F1) (YKL-40, AUC = 0.809; HA, AUC = 0.805). After IFN therapy, only YKL-40 values significantly decreased not only in the responder group, but also in the nonresponder group (P = 0.03). CONCLUSION: YKL-40 may be a useful non-invasive serum marker to estimate the degree of liver fibrosis and to evaluate the efficacy of IFN therapies in patients with HCV-associated liver disease.
文摘目的:检验广泛性焦虑量表(GAD-7)在军人群体中的信度与效度。方法:采用分层随机抽样方法抽取553名军人完成GAD-7、患者健康问卷抑郁症状群量表(PHQ-9)的评定;随机抽取113名接受美国精神障碍诊断和统计手册第4版临床定式访谈(Structured Clinical Interview for DSM-IV,SCID),并计算GAD-7的信度系数、敏感度、特异度等。结果:GAD-7的内部一致性系数为0.876;GAD-7与PHQ-9总分相关系数为0.653。在与SCID比较时,GAD-7的灵敏度为92.3%,特异度为90.5%,Kappa值为0.847(P<0.05)。ROC曲线中,在GAD-7截点值取10分时,灵敏度和特异度分别为89%和82%,曲线下面积为91.7%。结论:GAD-7在军人群体应用中具有较好的信度和效度。
