Setting minimum clinical performance specifications for tests based on disease prevalence and minimum acceptable positive and negative predictive values: Practical considerations applied to COVID-19 testing

ObjectivesSeveral guidelines for the evaluation of laboratory tests for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection have recommended establishing an a priori definition of minimum clinical performance specifications before test selection and method evaluation.MethodsUsing positive (PPV) and negative predictive values (NPV), we constructed a spreadsheet tool for determining the minimum clinical specificity (conditional on NPV or PPV, sensitivity and prevalence) and minimum clinical sensitivity (conditional on NPV or PPV, specificity and prevalence) of tests.ResultsAt a prevalence of 1%, there are no minimum sensitivity requirements to achieve a desired NPV of 60%-95% for a given clinical specificity above 20%. It is not possible to achieve 60–95% PPV even with 100% clinical sensitivity, except when the clinical specificity is near 100%. The opposite trend is seen in high prevalence settings (60%), where a relatively low minimum clinical sensitivity is required to achieve a desired PPV for a given clinical specificity, and a higher minimum clinical specificity is required to achieve a desired NPV for a given clinical sensitivity.DiscussionThe selection of laboratory tests and the testing strategy for SARS-CoV-2 involves delicate trade-offs between NPV and PPV based on prevalence and clinical sensitivity and clinical specificity. Practitioners and health authorities should carefully consider the clinical scenarios under which the test result will be used and select the most appropriate testing strategy that fulfils the a priori defined clinical performance specification.     

乳腺照相辅以导丝定位活检对诊断乳腺原位癌的意义

目的 探讨乳腺X线钼靶照相辅以细针穿刺导丝定位活检技术对提高原位癌诊断率的意义。方法 收集1997—2000年病理确诊的乳腺癌679例；以及近半年来手术或活检病理证实的乳腺癌74例，术前51例行乳腺钼靶照相，其中4例行定位活检。比较两个时期乳腺原位癌的发现率。结果 1997—2000年679例乳癌患者原位癌18例，占乳癌2．7％。近半年来74例乳癌患者中，原位癌4例，发现率为5．4％。比1997—2000年明显增高。结论 乳腺钼靶X线照相及穿刺定位活检技术可以提高原位癌的诊断率。     

超声与钼靶摄影诊断乳腺导管内癌的对照研究

目的评价超声、钼靶摄影以及二者综合对乳腺导管内癌的诊断准确性。 方法分析经病理证实的83例乳腺导管内癌的钼靶摄影和超声表现，并比较其诊断准确性。 结果（1）超声表现腺体内低回声实性病变52例（62．7％），导管内实性结节16例（19．3％），囊性病变或乳腺导管扩张7例（8．4％），阴性8例（9．6％）；（2）钼靶摄影表现簇状微小钙化53例（63．9％），软组织结节或局部密度增高50例（60．2％），未发现明确病变者9例（10．8％）；（3）分类比较超声、钼靶摄影和二者综合分类为可能恶性者分别为47例、53例、67例，2种方法准确率差异无统计学意义（56．6％和63．9％，P=0．169）；综合2种方法后诊断准确率高于钼靶摄影（80．7％和63．9％，P〈0．001）。 结论超声和钼靶摄影诊断导管内癌的准确率较低。综合应用2种检查方法可提高诊断准确率。     

乳腺导管内原位癌和内癌微小浸润的声像图表现及其病理基础

目的探讨乳腺导管内原位癌（ductal carcinoma in situ，DCIS）和乳腺导管内癌微小浸润（intraductal carcinoma with microinvasion，DCMI）的声像图改变。 方法使用Philips HDI 3000型超声诊断仪分析8例DCIS或DCMI的声像图，并与病理对照。 结果8例均为单发病灶，其中5例形态不规则，3例呈椭圆形；边界均不清晰；内部均呈低回声，其中1例伴有囊变；6例伴有点状强回声；病变后方回声均无改变；5例内部可见少量血流信号。大体标本均未见有包膜。6例病理诊断为DCMI，2例为DCIS，其中分别有5例和1例伴有粉刺状坏死。 结论DCIS及DCMI在声像图上具有一些特点。     

乳腺导管内癌伴微浸润相关超声及病理特征的Logistic回归分析

目的应用Logistic回归分析临床、病理及超声特征对乳腺导管内癌是否伴有微浸润的诊断价值,确定伴有微浸润危险因素。方法回顾性分析导管内癌(DCIS)患者64例、导管内癌伴微浸润(DCISM)80例,在9项临床、5项病理、10项超声特征方面进行单因素及多因素Logistic回归分析。结果多因素分析临床资料均不是DCISM危险因素(P>0.05),分子生物学HER2阳性、病理组织高级别、声像图边缘不光整、低回声、富血供是DCISM危险因素(P<0.05)。多因素分析诊断导管内癌是否伴有微浸润灵敏度82.5%、特异度92.2%、ROC曲线下面积0.941。结论多因素分析对乳腺导管内癌是否伴有微浸润具有良好的诊断价值,分子生物学HER2阳性、病理组织高级别、声像图边缘不光整、低回声、富血供是DCISM危险因素。     

尿液有形成分两种仪器检测结果的分析与比较

[目的]分析和探讨流式细胞仪UF1000i和尿化学分析仪CLINITEK500检测尿液有形成分的临床应用价值。[方法]3836份尿液标本以流式细胞仪UF1000i分析系统检测红细胞（RBC）、白细胞（WBC）、管型（CAST）等成分,尿化学分析仪CLINITEK500测定尿液中LEU、BLD、PRO等指标,与显微镜下人工判定的结果进行比较。[结果]尿流式细胞分析仪在灵敏度、特异性、准确度、阳性预测值和阴性预测值都优于尿化学分析仪,经X2检验在a=0．05水准,两者差异有统计学意义（P〈0．05）。[结论]两种仪器联合应用可以降低单用其中一种仪器的假阳性及假阴性率。     

乳腺浸润性导管癌的X线分析

目的　分析乳腺浸润性导管癌的钼靶X线特征 ,提高影像学诊断水平。方法　 3 7例经病理证实的乳腺浸润性导管癌 ,钼靶摄取乳腺轴、斜位片 ,分析其影像学表现。结果　主要X线表现 :3 7例中显示肿块影 3 3例 ,占 89.2 % ;显示毛刺状改变 18例 ,占 48.6% ;细小钙化如精盐样 12例 ,占 3 2 .4% ;所显示肿块较临床触诊扪及为小 2 6例 ,占显示肿块病例的78.8%。结论　乳腺浸润性导管癌在X线上有较特征性表现 ,乳腺钼靶检查是诊断此病最基本的影像学方法 ,有助于临床制定合理的治疗方案。     

Sonoelastography findings of supraspinatus tendon in rotator cuff tendinopathy without tear: comparison with magnetic resonance images and conventional ultrasonography

Background and purpose

Sonoelastography (SE) is a new technique that can assess differences in tissue stiffness. This study investigated the performance of SE for the differentiation of supraspinatus (SSP) tendon alterations of tendinopathy compared to magnetic resonance imaging (MRI) and conventional ultrasonography (US).

Methods

One hundred and eighteen consecutively registered patients with symptoms and MRI findings of SSP tendinopathy were assessed with US and SE. Coronal images of the SSP tendon were obtained using US and SE. Increased signal intensity on T2-weighted images in the coronal planes were graded according to the extent of the signal changes from ventral to dorsal. SE images were evaluated by reviewers using an experimentally proven color grading system.

Results

Using SE, 7.6 % of the SSP tendons were categorized as grade 0, 30.5 % as grade 1, 19.5 % as grade 2, and 42.4 % as grade 3. Evaluation of the interobserver reliability of the SE findings showed “almost perfect agreement”, with a weighted kappa coefficient of 0.83. By comparing the MRI findings with the SE findings, grades of MRI and SE had a positive correlation (r = 0.829, p = <0.001). Furthermore, grades of US and SE also had a positive correlation (r = 0.723, p = <0.001).

Conclusions

SE is valuable in the detection of the intratendinous and peritendinous alterations of the SSP tendon and has excellent interobserver reliability and excellent correlation with MRI findings and conventional ultrasonography findings.     

早期乳腺导管癌的超声诊断

目的：探讨早期乳腺导管癌超声声像图特点，提高超声诊断水平。方法：回顾性分析33例经病理证实为早期乳腺导管癌的超声图像资料。结果：早期乳腺导管癌超声表现复杂，肿瘤大小为9～80mm形态：类圆形8例，分叶状4例，不规则形20例；边界：模糊12例，尚清晰20例；微小钙化斑：未见16例，少量11例，呈满天繁星状5例；后方回声：衰减8例，增强5例，无改变19例。根据肿块二维超声表现，将其分为6种类型。超声诊断准确率81．8％，漏诊1例。结论：超声检查为早期乳腺导管癌有效检查方法。充分认识其超声表现，对正确诊断有一定帮助。     

细针穿刺定位活检对诊断早期乳腺癌的意义

目的 探讨细针穿刺导丝定位活检(FNL)对诊断早期乳腺癌的意义。方法 28例临床触诊阴性、乳腺钼靶照相可疑病变的患者，根据轴位及侧位摄片显示的病灶位置，将穿刺细针穿入，并将导丝留置于病变内，随后外科医师沿留置的导丝将病灶切除，行病理检查。结果 5例病灶病理诊断为原位癌，1例浸润癌，阳性率为23．1％，患者行局部放射治疗，一年后未见转移及复发。1例轻度非典型增生伴导管内乳头状瘤，另6例为良性病变，14例为乳腺组织增生，1例穿刺失败。结论 细针穿刺定位活检不仅可以提高早期乳腺癌的诊断率，而且可以协助治疗。     

Clinical tests for screening and diagnosis of cervical spine myelopathy: a systematic review

Objective

The purpose of this review was to investigate the diagnostic accuracy for screening and confirmation of clinical tests for cervical spine myelopathy (CSM) and to investigate the quality of the studies that have investigated these values.

Methods

This study was a systematic review that used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Search terms for PubMed included myelopathy; diagnosis, differential; sensitivity and specificity; and physical examination. Search terms for Cumulative Index to Nursing and Allied Health Literature were limited to myelopathy and sensitivity and specificity. Qualitative assessment included report of diagnostic accuracy metrics (sensitivity, specificity, and positive and negative likelihood ratios) and quality scores using the Quality Assessment of Diagnostic Accuracy Studies tool. Scores were created for single tests and clustered test findings.

Results

After evaluation, 12 full-text articles were selected, scored, and tabulated. Nearly all of the 18 tests demonstrated high levels of specificity and low levels of sensitivity, suggesting that they are poor screening tools. Only one study was scored as high quality. One study involved clustering of test findings but was considered low quality.

Conclusion

Nearly all of the clinical tests for CSM seem to be poor screening tools, which implies that manually oriented clinicians may perform treatment methods in a situation of doubt or uncertainly. More high-quality studies are needed, and manual therapists need to be cognizant that the current clinical tests for CSM lack strong diagnostic accuracy measures that are necessary for clinical decision making.     

乳腺原位癌的高频超声诊断评价

目的评价乳腺原位癌的高频超声诊断意义。方法回顾性分析41例乳腺原位癌的高频超声声像图征象,常规记录病变区形态、边界、内部回声、微钙化、后方回声等声像图改变,并与钼靶摄片检查征象(微小钙化、肿块结节影)进行对照分析。结果41例乳腺原位癌中,高频超声检查有阳性发现的共34例,其声像图表现可归纳为以下三型:(1)肿块型(伴或不伴微小钙化)18例;(2)导管型(伴或不伴微小钙化)13例;(3)单纯微钙化型共3例。41例原位癌中钼靶摄片显示有微钙化的29例,占本组病例的71%,高频超声对微小钙化的检出率为69%(20/29)。钼靶显示肿块结节影的有20例,仅占49%。本组病例中,超声诊断提示恶性倾向的有21例,诊断准确率为51%(21/41)。钼靶摄片的诊断准确率为59%,而超声与钼靶相互结合综合判断,诊断准确率可提高至76%。结论在乳腺原位癌的诊断中,高频超声检查既弥补了钼靶摄片的不足,且可以提高钼靶诊断的特异性。超声检查与钼靶摄片的相互结合、相互补充是提高其诊断准确率的关键。     

乳腺导管内癌的超声表现与病理对照研究

目的探讨超声检查对乳腺导管内癌的诊断价值。方法对38例乳腺导管内癌患者进行常规二维高频超声及彩色多普勒超声检查,观察其二维声像图特征及血流特点,并经手术后病理证实,将超声检查结果与病理结果对照分析。结果乳腺导管内癌超声图像包括三个类型(1)实性肿块型;(2)囊实混合性回声型;(3)导管扩张型。结论常规二维高频超声及彩色多普勒超声检查对乳腺导管内癌的检出有重要的诊断价值,但由于缺乏特异性,需联合其他影像检查方法。     

乳腺导管内癌的超声诊断及误诊分析

目的:探讨乳腺导管内癌的超声表现及误诊原因。方法:回顾分析经手术病理证实的17例乳腺导管内癌的超声声像图特征。结果:17例病灶中,超声诊断恶性肿瘤14例,良性病变2例,1例未发现肿块;超声诊断符合率为82.3%。根据文献和本研究中病灶的声像图特征,将17例病变分为5类:实性肿块型(6例),导管扩张型(5例),结构紊乱型(4例),囊性病灶型(1例),其他类型(1例)。结论:乳腺导管内癌的超声表现多样,充分认识乳腺导管内癌的超声声像图特征可减少误诊,结合钼靶及乳腺导管内镜检查可以减少漏诊。     

18F-FDG PET/CT对宫颈癌术后临床怀疑复发和转移病人中的应用价值

目的观察¹⁸F-氟代脱氧葡萄糖(¹⁸F-FDG)正电子发射断层显像技术/计算机体层扫描(PET/CT)对宫颈癌术后临床怀疑复发与转移患者的诊断价值。方法前瞻性纳入喀什地区第一人民医院2018年7月至2020年11月期间收治的118例宫颈癌术后怀疑复发与转移患者为研究对象,采用随机数字表法其分为观察组(n=59)与对照组(n=59)。对照组予给予以常规血清癌抗原19-9(CA19-9)检测,观察组行¹⁸F-FDG PET/CT检查。2组均以组织病理学结果为金标准,评估2组对宫颈癌怀疑复发与转移的诊断价值并对比组间差异。结果¹⁸F-FDG PET/CT检查诊断对宫颈癌复发及转移的特异度(76.92%)、灵敏度(93.48%)以及准确率(89.83%)均显著高于CA19-9检测(38.46%、60.87%、55.93%),2组比较差异有统计学意义(P<0.05),同时观察组诊断结果与组织病理学结果吻合度较高(Kappa=0.766,P<0.05)。结论¹⁸F-FDG PET/CT检查应用于宫颈癌术后临床怀疑复发与转移的诊断,可清晰显示其状况,灵敏度、准确率等均明显高于血清CA19-9检测。     

乳腺浸润性导管癌组织中表皮钙黏蛋白的表达及其意义

目的 探讨乳腺浸润性导管癌中表皮钙黏蛋白(E-cadherin,E-cad)的表达及其意义.方法 选取2005年1月-2009年12月的组织病理切块,用免疫组织化学EnVision二步法检测63例乳腺浸润性导管癌(invasiveductal carcinoma,IDC)组织中E-cad的表达情况,设为IDC组;另检测...     

Representativeness of nodal sampling with endobronchial ultrasonography in non-small-cell lung cancer staging

The objective of our study was to determine the procedure-related requirements of mediastinal node sampling with endobronchial ultrasonography with real-time transbronchial needle aspiration (EBUS-TBNA) that would provide negative predictive value (NPV) for the identification of stage III disease in non-small-cell lung cancer (NSCLC) high enough to consider the technique equivalent to cervical mediastinoscopy. Representative EBUS-TBNA was defined as a sampling procedure obtaining satisfactory samples from normal nodes in regions 4R, 4L and 7 or diagnosing malignancy in mediastinal nodes. NPV was estimated using the results of postsurgical staging in patients who underwent surgery as a reference. Two-hundred ninety-six patients staged with EBUS-TBNA were included. Representative samples from regions 4R, 4L and 7 showing nonmalignant cytology were obtained from 98 patients (33.1%) and EBUS-TBNA detected N2/N3 disease in 150 (50.7%). Accordingly, an EBUS-TBNA procedure accomplishing the representativeness criteria required for sampling was attained in 248 of the participating patients (83.8%). The NPV of the procedure in this setting was 93.6%, with false-negative results only found in 5 patients, four of them with nodal metastasis out of the reach of EBUS-TBNA (regions 5, 8 and 9). In conclusion, representative sampling of regions 4R, 4L and 7 is achieved in more than 80% of patients staged using EBUS-TBNA, and in the procedures that attain this requirement a NPV >90% for mediastinal malignancy is reached, a figure equivalent to cervical mediastinoscopy.     

乳腺浸润性导管癌的高频彩色多普勒超声诊断分析

目的分析乳腺浸润性导管癌的高频声像图特征、彩色多普勒血流特点及临床意义。方法对206例经手术、病理证实为乳腺浸润性导管癌的高频声像图、彩色多普勒表现及临床资料进行回顾性分析。结果超声诊断乳腺浸润性导管癌185例,在高频声像图上绝大部分有典型的恶性特征,但也有肿块细小,超声表现不典型者。形态不规则的低回声结节、伴有斑点状钙化及丰富的血流信号为乳腺浸润性导管癌的特征性表现。其血流具有一定的形态特征,脉冲多普勒频谱呈现高阻力指数。结论利用高频超声结合彩色多普勒在乳腺浸润性导管癌中的特有表现,可以提高乳腺浸润性导管癌的诊断符合率,有利于临床制定合理的治疗方案。