A systematic review classifies sources of bias and variation in diagnostic test accuracy studies

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.     

Transport Mobility for Children and Adolescents with Cerebral Palsy (CP)

Background: The transport mobility of children and adolescents with cerebral palsy (CP) is of vital interest for the individual, as well as for society. Enhanced transport mobility can be related to improved functional health status and a higher degree of autonomy, which in turn may reduce the demand for societal support. UN Resolution 48/96, together with Swedish legislation and ''Vision Zero'' have in different ways established that the transport system must be designed to meet also the needs of children and adolescents with disabilities. Hence, it is necessary to identify and eliminate obstacles hindering children and adolescents with CP from using public transport and other means of transport, such as their own cars, at the same level as other members of society. However, in the case of children and adolescents with CP, the transport situation and the learner driver's educational situation have so far been largely unknown. Aim: The general aim of the thesis was to describe and analyse, from a legislative and a public health perspective, the transport mobility situation for children and adolescents with CP. Furthermore, the general aim was to identify obstacles for the target group to use public transport and other means of transportation, at the same level as other members of the society, and to suggest improvements that will remove the identified obstacles. Material and methods: Several different data collection methods were used. Data, concerning travel habits and parents' perceived risks regarding transportation, were taken from a postal questionnaire addressed to parents of children and adolescents with CP. In order to estimate the numbers of potential learner drivers with CP in each age group in Sweden, a literature review was conducted, based on Swedish material. Furthermore, logbooks for learner drivers with CP were analysed retrospectively, in order to identify procedures, problems and key tasks in their driver education. Visual search strategies for learner drivers with CP were analysed, utilizing an eye tracker, and an attempt was made to introduce a screening tool for predicting the outcome of driver education. Results: Children and adolescents with CP were found to be transported under unsafe conditions, causing worry among their parents. When transporting children in the family vehicle, the parents were exposed to a very heavy burden, which increased their worry. The prevalence of potential learner drivers with CP who were in need of highly specialised driver education, including individually adapted driver training vehicles, was estimated to be 0.15 per 1,000 of a population-based age group of learner drivers in Sweden. Complex procedures, structural problems and financial obstacles made it difficult for adolescents with CP to obtain a driving licence and an adapted vehicle. The total duration of the driving tuition given by a driving instructor was found to be almost nine times higher for learner drivers with CP than for non-disabled learner drivers. Visual search strategies among learner drivers with CP were found to be less flexible than among other learner drivers. This fact indicated a need for better methods of teaching such strategies to this group as an integral component of their driver education. The validity of the motor-free visual perceptual test, TVPS-UL, for predicting the outcome of driver education for learner drivers, was found to be low. In order to find a reliable and valid screening tool for this purpose, future studies should focus on cross-validation of visual perceptual and dual task performance tests for different types of independent variables, such as obtaining a driving licence or not, accident involvement and driving ability. Conclusion: The transport system was found, from a legislative and public health perspective, to be unsuitable to meet the needs of children and adolescents with CP. Suggestions for improving transport mobility for children and adolescents with CP are provided. Several of these suggestions are practical, concrete and contextual for Swedish conditions, and some of them necessitate future research. However, a number of these suggestions are also applicable in an international context.     

QuickCheck检测加速器的能力测试与评估

目的：在改变测量条件和标准条件的情况下进行测量,对比测量结果,检测QuickCheck的性能,为加速器的晨检及检测结果判读提供依据。方法：通过改变输出剂量、射野大小、SSD、准直器角度和机架角,评估QuickCheck的检测能力。QuickCheck检测的射野参数与三维水箱等测量进行对比。结果：输出剂量增大1 cGy或减小6 cGy,射野改变≥0.2 cm;SSD减小2 cm或增大1 cm,准直器旋转≥2 o,机架角旋转≥6 o,检测结果超过阈值。与三维水箱测量的结果相比,平坦度、对称性（G/T）和（L/R）及剂量率分别相差3.84%、0.67%、0.47%,1.2 MU/min。结论：QuickCheck在检测输出剂量、射野大小、准直器角度、平坦度、对称性及剂量率方面准确度很高,能够满足日常加速器质量保证的需要。在检测SSD、机架角偏差方面能力较弱。     

Gel Agglutination Test: Its Application to Infertile Men

In a study involving 253 men attending the Male Fertility Clinic in Nottingham, the Gelatin Agglutination Test on serum gave a positive response in 14.2% of patients and a positive response at a dilution of 1/32 in 11.5% of patients. No correlation was found between a positive GAT response and increasing age or the major pathological entities causing infertility in the male. Of the positive GAT responses, 17% reverted to negative on second testing. The value and the diagnostic importance of this test as well as its reliability is questioned.     

The Upper Limb Tension Test: Inter-tester Reliability for Assessing the Onset of Passive Resistance R 1

Abstract

The aim of this trial was to assess the inter-tester reliability of the Upper Limb Tension Test (ULTT). The onset of passive resistance (R1) of the left elbow was determined by four experienced manual therapists in a group of asymptomatic subjects. A recording of the degrees of elbow extension was obtained using a goniometer, having first positioned the upper extremity in a bracket maintaining 110 degrees of shoulder abduction and 10 degrees of shoulder extension. Each rater then moved the subjects' left shoulder into full external rotation and the forearm into full supination with the wrist and fingers in a neutral position. Data was collected four consecutive days. The data was analyzed by a two-way analysis of variance. The means of the readings among the four raters was found to be significantly different. It was concluded that the ULTT has a low inter-tester reliability when R1 is compared. Several suggestions are made for future research projects in this area.     

CysC、Hcy、HbAlc、hs-CRP在糖尿病早期肾损伤中的应用研究

目的探索筛选糖尿病早期肾损伤的最佳检验指标,并评价其应用价值。方法选取2010年5月至2012年5月接受治疗的200例糖尿病早期肾损伤患者为实验对象(实验组),选取健康人群100名为对照组,对实验组和对照组应用常规检验方法和胱抑素C、同型半胱氨酸、糖化血红蛋白、超敏C反应蛋白进行同步对比试验研究。结果肾功能正常组和早期肾损伤患者组的各项指标差异有统计学意义(P<0.05),且同时测定4项指标的阳性检出率为92.00%,远远高于单项检测指标的81.00%。结论同时测定胱抑素C、同型半胱氨酸、糖化血红蛋白、超敏C反应蛋白中筛选糖尿病早期肾损伤的检验方法准确率高。     

Disease susceptibility genes for autism

Autism is a complex neurodevelopmental disorder characterized by impairment in social interaction accompanied by a delay or lack of language, restricted interests, stereotyped behavior, and repetitive movement. Genetic predisposition to autism is evident from family and twin studies, and heritability in idiopathic autism is estimated at over 90%. Frequency of the disorder is approximately 1:2000 with a male to female ratio of 4:1. Affected individuals look normal at birth, and the symptoms manifest at the first 2-3 years of life. The spectrum of clinical symptoms and the severity of the disorder are variable even among siblings. Family studies and several genome-wide linkage analyses support the hypothesis of complex inheritance with involvement of as many as 10-100 genes of moderate effect. Identification of genes responsible for the phenotype would help to understand the molecular mechanisms of the disorder. Several genes have been proposed to play a role in susceptibility to autism, and this paper will overview those genes and their potential role in the disorder.     

Qualities of a French version of the Wolf Motor Function Test: A multicenter study

IntroductionThere are currently a small number of standardized tools in French that measure and compare the effect of constraint-induced movement therapy, or other recent therapies promoting motor recoveryObjectiveTo create a French version of the Wolf Motor Function Test (WMFT) and assess its reliability, minimal detectable change, and criterion validity.MethodProspective multicenter repeated-measure design with 44 patients with post stroke hemiparesis. A French Version of the WMFT was created; it was then assessed against the Fugl Meyer Assessment-Upper Extremity (French version) to establish its reliability, the minimal detectable change and its validity.ResultsInter-rater reliability was very good. Reproducibility of the scores was good. Cronbach α coefficients showed adequate internal consistency. The minimal detectable change (MDC_95%) for functional ability scores was below 10% of the highest possible score; the MDC_95% for performance time was very high at more than 90 seconds. Criterion validity was good.ConclusionThe French version of the WMFT is reliable and valid. The test shows promise for use as an objective outcome measure for people post stroke in French speaking countries.     

大学生色觉辨别能力与深度知觉的相关性分析

目的：评价色觉正常大学生的色觉辨别能力与深度知觉的关系。方法：选取巴什肯特大学医学专业学生52例,其中男性33例（63．46％）,女性19例（36．54％）,平均年龄21．18±2．52岁。参与学生视力正常（20／20）,且经Ishihara假同色测试法显示无先天性色觉缺陷。运用Gundogan方法确定主视眼（ DE ）。通过法－孟二氏100色度试验（FM100HT）检验色觉辨别能力,包括左右眼及双眼（TE）的总误差分（ TES ）、部分误差分（ LES ）。误差分分为三组：双眼、DE及非主视眼（ NDE ）。应用TNO检查双眼视觉与立体感,并根据480－15 arc／s范围的立体感水平分为四组。结果：FM100HT的误差分显示无性别差异的TES,蓝黄LES和红绿 LES 分别为61．22±30．32（58．50）[ mean ± SD],35．80±19.32（36．50）和25．42±14．65（24．00）。男性受试者（n＝31）分别为67．45±29．95（61．00）,40．25±18．83（39．00）和27．19±14．30（24．00）。女性受试者（n＝19）分别为51.05±28．84（47．00）,25．52±18．32（28．00）和22．52±31.13（23．00）。根据FM100 HT的误差分,得出女性颜色视觉辨别能力高于男性。通过FM100 HT将色觉辨别能力分为较高（6％,TES＝0～20）,中等（86％,TES＝20～100）和较低（8％, TES＞100）,中等水平最为常见（ P＜0.05）。 DE和NDE的红绿LES 分别为24．12±14．70和32．20±14．21, DE 和 NDE 的蓝黄 LES 分别为34．68±18.95和36．24±17．56。女性（ n＝19） DE和NDE的红绿色LES分别为21．89±15．06和31．00±22．42;男性（ n＝31）则为25．48±14．55和32．93±17．31。女性（ n＝19） DE和NDE 蓝黄色 LES 分别为29．63±18．62和33．42±17.38,男性（ n＝31）则为37．77±18．78和37．96±17．73。所有学生的TE,DE及NDE的TES和立体视觉水平均进行比较,差异均无统计学意义（P＝1）。研究表明色觉辨别能力和双眼深度知觉无关。结论：FM100 HT的TES显示：正常人不同个体立体视觉水平无差异,基于色觉分离的TNO检测的深度直觉与色觉辨别能力不相关。在之前的研究中, DE色觉辨别能力优于NDE。但目前研究表明在深度知觉方面DE并非优于NDE。     

《组织学与胚胎学》竞赛型考试方法

《组织学与胚胎学》考试方法进行了改革,试用了以竞赛型现场考试为特色,以态度考核及平时成绩为支撑的考试体系。其优点在于形式新颖、多样,激发热情、创新,富有人文关爱,且纳入了过程评价和结果评价,受到了学生欢迎。同时还注意到,应增大笔试比例来维持公平性。