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41.
Penny F. Whiting Anne W.S. Rutjes Marie E. Westwood Susan Mallett 《Journal of clinical epidemiology》2013,66(10):1093-1104
ObjectiveTo classify the sources of bias and variation and to provide an updated summary of the evidence of the effects of each source of bias and variation.Study Design and SettingWe conducted a systematic review of studies of any design with the main objective of addressing bias or variation in the results of diagnostic accuracy studies. We searched MEDLINE, EMBASE, BIOSIS, the Cochrane Methodology Register, and Database of Abstracts of Reviews of Effects (DARE) from 2001 to October 2011. Citation searches based on three key papers were conducted, and studies from our previous review (search to 2001) were eligible. One reviewer extracted data on the study design, objective, sources of bias and/or variation, and results. A second reviewer checked the extraction.ResultsWe summarized the number of studies providing evidence of an effect arising from each source of bias and variation on the estimates of sensitivity, specificity, and overall accuracy.ConclusionsWe found consistent evidence for the effects of case–control design, observer variability, availability of clinical information, reference standard, partial and differential verification bias, demographic features, and disease prevalence and severity. Effects were generally stronger for sensitivity than for specificity. Evidence for other sources of bias and variation was limited. 相似文献
42.
IntroductionThe UPDRS-IV represents the most common screening tool to assess motor fluctuations in patients with PD despite the lack of a clinimetric validation.ObjectivesWe evaluated sensitivity and specificity of UPDRS-IV using a 12-h waking-day motor assessment as the gold standard.MethodsWe consecutively enrolled PD patients who underwent a 12-h waking-day motor assessment in the study. Patients were clinically evaluated every 2 h for 12 h using the UPDRS-III. Motor scores were reported as a line graph and six blinded raters classified patients as having or not having motor fluctuations. The UPDRS-IV was used in order to assess the presence of predictable and unpredictable motor fluctuations according to items 36–38.ResultsSixty two PD patients were enrolled in the study. According to the raters' evaluations, 39 (62.9%) were classified as having motor fluctuations, while according to the UPDRS-IV 47 (75.8%) presented a motor fluctuation giving a sensitivity of 87.2% (95%CI 72.6–95.7) and a specificity of 43.5% (95%CI 23.2–65.5).ConclusionOur study results confirm the high level of sensitivity with a lower level of specificity of UPDRS-IV to screen motor fluctuations in PD patients. 相似文献
43.
BackgroundA plethora of research on facial emotion recognition in autism spectrum disorders (ASD) exists and reported deficits in ASD compared to controls, particularly for negative basic emotions. However, these studies have largely used static high intensity stimuli. The current study investigated facial emotion recognition across three levels of expression intensity from videos, looking at accuracy rates to investigate impairments in facial emotion recognition and error patterns (’confusions’) to explore potential underlying factors.MethodTwelve individuals with ASD (9 M/3F; M(age) = 17.3) and 12 matched controls (9 M/3F; M(age) = 16.9) completed a facial emotion recognition task including 9 emotion categories (anger, disgust, fear, sadness, surprise, happiness, contempt, embarrassment, pride) and neutral, each expressed by 12 encoders at low, intermediate, and high intensity.ResultsA facial emotion recognition deficit was found overall for the ASD group compared to controls, as well as deficits in recognising individual negative emotions at varying expression intensities. Compared to controls, the ASD group showed significantly more, albeit typical, confusions between emotion categories (at high intensity), and significantly more confusions of emotions as ‘neutral’ (at low intensity).ConclusionsThe facial emotion recognition deficits identified in ASD, particularly for negative emotions, are in line with previous studies using other types of stimuli. Error analysis showed that individuals with ASD had difficulties detecting emotional information in the face (sensitivity) at low intensity, and correctly identifying emotional information (specificity) at high intensity. These results suggest different underlying mechanisms for the facial emotion recognition deficits at low vs high expression intensity. 相似文献
44.
HR Seneviratne D Lankeshwara S Wijeratne N Somasunderam D Athukorale 《BJOG : an international journal of obstetrics and gynaecology》2009,116(13):1722-1728
Objective To evaluate serum insulin levels and insulin sensitivity in women with polycystic ovary syndrome (PCOS) in relation to their glycaemic status.
Design An observational study.
Setting A tertiary-level reproductive health centre in Sri Lanka.
Sample Infertile women diagnosed as having PCOS ( n = 168) on the basis of the Rotterdam criteria were included in the study.
Methods Glycaemic status and serum insulin values were assessed at fasting and at 2 hours after a 75-g oral glucose load and stratified as diabetes mellitus (DM) (10.12%), impaired glucose tolerance (IGT) (23.21%) and normoglycaemia (66.67%). The normoglycaemic group was restratified as groups A (10.7%), B (79.5%) and C (9.8%) on the basis of serum insulin levels, with group A having the lowest and group C the highest values. The Quantitative Insulin Sensitivity Check Index (QUICKI) scores of women with DM and IGT and those in groups A, B and C in the normoglycaemic category were compared.
Main outcome measures Insulin sensitivity in these groups of women.
Results Body mass index (BMI) exceeded 23 kg/m2 in 77.38% of the women. In normoglycaemic women with PCOS, insulin sensitivity was highest in group A. In groups B and C, insulin sensitivities corresponded to those found for women with IGT and DM respectively. This pattern was also reflected in the BMI.
Conclusions Normoglycaemic women with PCOS are heterogeneous regarding insulin sensitivity. The treatment offered to those with DM and IGT could be extended to subgroups B and C of normoglycaemic subjects. Normoglycaemic women with PCOS with high insulin sensitivity (group A) would not qualify for this treatment. 相似文献
Design An observational study.
Setting A tertiary-level reproductive health centre in Sri Lanka.
Sample Infertile women diagnosed as having PCOS ( n = 168) on the basis of the Rotterdam criteria were included in the study.
Methods Glycaemic status and serum insulin values were assessed at fasting and at 2 hours after a 75-g oral glucose load and stratified as diabetes mellitus (DM) (10.12%), impaired glucose tolerance (IGT) (23.21%) and normoglycaemia (66.67%). The normoglycaemic group was restratified as groups A (10.7%), B (79.5%) and C (9.8%) on the basis of serum insulin levels, with group A having the lowest and group C the highest values. The Quantitative Insulin Sensitivity Check Index (QUICKI) scores of women with DM and IGT and those in groups A, B and C in the normoglycaemic category were compared.
Main outcome measures Insulin sensitivity in these groups of women.
Results Body mass index (BMI) exceeded 23 kg/m
Conclusions Normoglycaemic women with PCOS are heterogeneous regarding insulin sensitivity. The treatment offered to those with DM and IGT could be extended to subgroups B and C of normoglycaemic subjects. Normoglycaemic women with PCOS with high insulin sensitivity (group A) would not qualify for this treatment. 相似文献
45.
背景:临床研究发现,替加色罗可以明显改善肠易激综合征患者的腹部不适和腹痛,但其调节内脏感觉的机制目前尚不清楚。目的:观察替加色罗对结肠炎诱导的大鼠腰骶髓Fos、P物质(SP)和降钙素基因相关肽(CGRP)表达的影响,探讨替加色罗降低内脏敏感性的作用途径。方法:成年雄性Sprague-Dawley大鼠24只,以三硝基苯磺酸灌肠诱导结肠炎并随机分为实验组1:替加色罗灌胃,每天2mg/kg;实验组2:替加色罗灌胃,每天1mg/kg;对照组:生理盐水灌胃,2.0ml/d。连续灌胃7天后,采用免疫组化方法检测大鼠腰骶髓Fos、SP和CGRP的表达。结果:结肠炎可诱导对照组大鼠腰骶髓(L5~S1)背角深层Fos表达以及背角浅层SP和CGRP表达。实验组1大鼠腰骶髓背角Fos阳性神经元数(22.0±7.7)和SP密度(12.5%±1.4%)显著低于对照组(62.2±18.9和35.9%±8.9%,P<0.05),CGRP密度(1.2%±1.1%)与对照组(2.8%±2.4%)相比无显著差异。实验组2大鼠腰骶髓背角Fos、SP和CGRP的表达与对照组相比均无显著差异。结论:替加色罗可以明显减少结肠炎诱导的大鼠腰骶髓背角Fos和SP的表达,其降低内脏敏感性的作用可能与抑制脊髓背角SP的表达有关。 相似文献
46.
金瑄 《标记免疫分析与临床》2015,22(8):744-746
目的 调查研究小儿支原体肺炎感染患者肺炎支原体抗体(MP-Ab)及超敏C反应蛋白(hs-CRP)水平的变化,探讨肺炎支原体抗体与超敏C反应蛋白联合检测对小儿支原体肺炎感染的临床诊断价值.方法 肺炎支原体肺炎患儿110例,对照儿童120例,均按照《诸福棠实用儿科学》中支原体肺炎诊断标准确诊,两组分别进行MP-Ab、hs-CRP检测,肺炎支原体抗体判定以MP-Ab滴度≥1:160为阳性,超敏C反应蛋白判定以hs-CRP> 5mg/L为阳性.通过分析MP-Ab检测法与MP-Ab联合hs-CRP检测法敏感性、特异性差异,探讨MP-Ab联合hs-CRP检测法诊断小儿支原体肺炎感染的临床意义.结果 肺炎支原体肺炎患儿组MP-Ab滴度≥1∶160比率高于正常对照组,肺炎支原体肺炎患儿组hs-CRP高于正常对照组,差异均有统计学意义(P<0.05);MP-Ab检测法诊断肺炎支原体肺炎的灵敏度为78.2%,MP-Ab联合hs-CRP检测法诊断肺炎支原体肺炎的灵敏度为89.1%,MP-Ab联合hs-CRP检测肺炎支原体肺炎的灵敏度高于MP-Ab检测法,差异有统计学意义(P<0.05);MP-Ab检测法诊断肺炎支原体肺炎的特异度为94.2%,MP-Ab联合hs-CRP检测法诊断肺炎支原体肺炎的特异度为89.2%,差异无统计学意义(P>0.05).结论 MP-Ab与hs-CRP联合检测能提高小儿支原体肺炎感染的诊断率,具有较高临床价值. 相似文献
47.
Beth Bennett Mary Beeson Lena Gordon Thomas E. Johnson 《Alcoholism, clinical and experimental research》1997,21(5):767-772
Numerous algorithms for the identification and genetic mapping of quantitative trait loci (QTL) have been developed. Methods for confirming QTL maps involve either examination of independent segregating populations or the construction of congenic lines differing only in the QTL of interest. Because these projects require a minimum of several years or thousands of marker assessments in laboratory mice, an alternative, faster congenic method has been pro: posed. In a preliminary study, we tested this method for confirming QTLs identified in crosses between the ILS and ISS selected lines of mice for differential sensitivity to the hypnotic effects of ethanol. Herein, we report the construction of "segregating congenic" strains in which each QTL is made homozygous in a single generation, whereas the remainder of the genetic background is allowed to segregate. Sensitivity to ethanol among the progeny of such mice is consistent with predictions. Phenotypic variation is high, as expected, due to the background segregation, and statistical significance was attained in only 2 of 7 comparisons. Such segregating congenic populations may be a valuable research tool for confirming QTL map positions and for subsequent assessment of individual pathways and mechanisms of action of individual QTLs. 相似文献
48.
目的:通过人工诱导建立肿瘤坏死因子相关凋亡诱导配体(TRAIL)获得性耐药的肺癌细胞系,氯化锂联合rhTRAIL作用细胞,以期了解氯化锂增敏TRAIL的现象及机制。方法:通过低剂量rhTRAIL诱导人肺大细胞癌细胞系H460,建立TRAIL耐药细胞株H460R并鉴定,应用MTT和流式细胞术分析氯化锂和rhTRAIL联合给药后亲本株与耐药株细胞增殖和凋亡差异,应用RT-PCR和Western blot检测死亡受体表达。结果:rhTRAIL处理亲本株H460和耐药株H460R后细胞存活率存在显著差异(P<0.01),IC50分别为59.2ng/ml和294.8ng/ml。60ng/ml rhTRAIL处理耐药株及亲本株后平均细胞凋亡比例存在显著差异(10.5%vs 19.4%,P<0.01),耐药株表现出显著的TRAIL耐受现象。但联合20mmol/L氯化锂后,MTT及流式细胞术检测耐药株细胞增殖及凋亡发现H460R对rhTRAIL的敏感性显著增加。进一步研究发现死亡受体DR4和DR5的mRNA及蛋白水平升高,这可能是药物增敏的机制之一。结论:氯化锂能够增加获得性耐药细胞系H460R对TRAIL的敏感性,死亡受体表达增加是可能的增敏机制之一。 相似文献
49.
目的基于上转化发光(UPT)免疫层析技术,建立发热伴血小板减少综合征病毒(SFTSV)总抗体的现场快速检测方法。方法将SFTSV重组NP蛋白与上转化发光颗粒(UCP)偶联,制备UCP-NP免疫层析试纸条,评价该试纸条检测SFTSV总抗体的灵敏性、特异性和稳定性,并检测SFTSV血清254份,与酶联免疫法(ELISA)比较。结果该方法可在15min内完成SFTSV总抗体检测,可检测1∶500稀释度的SFTSV阳性血清,与其他出血热病毒无交叉反应,加样14d内稳定性较高。UPT免疫层析法与ELISA法检测临床血清样品一致性极高(Kappa=0.967),约登指数为0.973。结论建立了基于UPT免疫层析技术的SFTSV总抗体快速检测方法,该方法灵敏、特异,且操作简便、快速,结果稳定,适合在基层门诊和体检现场推广。 相似文献
50.
目的:探讨人乳头瘤病毒(HPV)E6/E7mRNA检测用于未明确诊断意义的不典型鳞状上皮细胞(ASCUS)诊断结果的判定价值。方法:对160例薄层液基细胞学检查诊断为ASCUS者进行HPV E6/E7mRNA和高危型HPV(HR-HPV)DNA检测,结合病理学诊断资料进行统计学分析。结果:160例中病理结果为宫颈上皮内瘤变Ⅱ级(CINⅡ)及以上级别者的HPV E6/E7mRNA阳性率明显高于CINⅡ以下级别者,差异有统计学意义(P0.05),但与HR-HPV DNA检测结果无统计学差异。HPV E6/E7 mRNA检测CINII及以上级别的灵敏度(69.2%)与HR-HPV DNA检测相比无统计学差异(P0.05);特异度(73.9%)高于HR-HPV DNA检测(61.9%),差异有统计学意义(P0.05)。结论:HPV E6/E7 mRNA检测可作为ASCUS者是否需要进行阴道镜检查的一项指标依据。 相似文献