Comparison of self-assessment of solvent exposure with measurement and professional assessment for female petrochemical workers in China

OBJECTIVE: The primary objective of this paper is to examine the validity of self-assessment of solvent exposure by comparing it with professional assessment and actual measurements. METHODS: Self-assessment of exposures to benzene, toluene, styrene, and xylene was obtained from 132 female workers. The exposures were also estimated by an occupational hygienist and by actual measurement. Self-assessment, professional assessment, and measurement were then compared with each other. RESULTS: Fair to good agreement was found between self-assessment, professional assessment, and measurement for benzene, styrene, and xylene. The agreement between self-assessment and measurement was poor for toluene, whereas the agreement between self-assessment and professional assessment was good. The latter was caused by a biased professional assessment. CONCLUSIONS: Workers' self-assessment and professional assessment provided useful information for benzene, styrene, and xylene exposure, but not for toluene exposure. False agreement can be obtained when professional assessment was used as reference in validity study.     

Measures of agreement between many raters for ordinal classifications

Screening and diagnostic procedures often require a physician's subjective interpretation of a patient's test result using an ordered categorical scale to define the patient's disease severity. Because of wide variability observed between physicians' ratings, many large‐scale studies have been conducted to quantify agreement between multiple experts' ordinal classifications in common diagnostic procedures such as mammography. However, very few statistical approaches are available to assess agreement in these large‐scale settings. Many existing summary measures of agreement rely on extensions of Cohen's kappa. These are prone to prevalence and marginal distribution issues, become increasingly complex for more than three experts, or are not easily implemented. Here we propose a model‐based approach to assess agreement in large‐scale studies based upon a framework of ordinal generalized linear mixed models. A summary measure of agreement is proposed for multiple experts assessing the same sample of patients' test results according to an ordered categorical scale. This measure avoids some of the key flaws associated with Cohen's kappa and its extensions. Simulation studies are conducted to demonstrate the validity of the approach with comparison with commonly used agreement measures. The proposed methods are easily implemented using the software package R and are applied to two large‐scale cancer agreement studies. Copyright © 2015 John Wiley & Sons, Ltd.     

Measuring health-related quality of life in adolescents: agreement between raters and between methods of administration

The aim of this study was to evaluate the agreement between children and proxies as well as the agreement between methods of administration in assessing Health-Related Quality of Life (HRQoL) using the TNO AZL Children's Quality Of Life (TACQOL) questionnaire. A random sample from a Dutch cohort of 14-year-old very low birth weight children and their parents were invited to participate in a face-to-face (n = 150) or telephone interview (n = 150). Participants were also sent a questionnaire by mail. The response rate was 83%. Inter-rater and intermethod agreement were generally good in observable HRQoL domains, and moderate in less readily observable, and possibly less stable, domains such as moods, pain and physical symptoms, and social functioning. In measuring children's HRQoL using the TACQOL, the results and their interpretation are dependent on the source of information and the method of administration.     

单增李斯特菌不同PCR快速检测方法比较

目的比较3种PCR快速检测方法在检测单核细胞增生李斯特菌时的特异性和灵敏度方面的差异。方法针对单核细胞增生李斯特菌的毒力基因iap和prfA基因,分别设计引物,进行单个PCR、多重PCR、套式PCR等3种方法检测。结果3种PCR方法均具有较强的特异性;套式PCR的灵敏度为10²cfu/ml,高于单个PCR(10³cfu/ml)和多重PCR(10⁴cfu/ml)。结论多重PCR在特异性检测方面具有优势,而在灵敏度方面,套式PCR要明显优于单个及多重PCR方法。     

三种终止中期妊娠方法的比较

目的:探讨三种终止中期妊娠方法的疗效.方法:180例中期妊娠患者随机分为三组,利凡诺羊膜腔内注射法58例,米非司酮配伍米索前列醇法62例,米非司酮联合利凡诺羊膜腔内注射法60例,比较三组引流产效果.结果:米非司酮配伍米索前列醇法和米非司酮联合利凡诺羊膜腔内注射法引产有效率明显高于利凡诺羊膜腔内注射法,且有效引产时间明显缩短,但米索前列醇的副作用多且明显.结论:米非司酮联合利凡诺羊膜腔内注射法终止中期妊娠引产有效率高,引产时间短,副作用小.     

Improving the reliability of diagnostic tests in population‐based agreement studies

Many large‐scale studies have recently been carried out to assess the reliability of diagnostic procedures, such as mammography for the detection of breast cancer. The large numbers of raters and subjects involved raise new challenges in how to measure agreement in these types of studies. An important motivator of these studies is the identification of factors that contribute to the often wide discrepancies observed between raters' classifications, such as a rater's experience, in order to improve the reliability of the diagnostic process of interest. Incorporating covariate information into the agreement model is a key component in addressing these questions. Few agreement models are currently available that jointly model larger numbers of raters and subjects and incorporate covariate information. In this paper, we extend a recently developed population‐based model and measure of agreement for binary ratings to incorporate covariate information using the class of generalized linear mixed models with a probit link function. Important information on factors related to the subjects and raters can be included as fixed and/or random effects in the model. We demonstrate how agreement can be assessed between subgroups of the raters and/or subjects, for example, comparing agreement between experienced and less experienced raters. Simulation studies are carried out to test the performance of the proposed models and measures of agreement. Application to a large‐scale breast cancer study is presented. Copyright © 2010 John Wiley & Sons, Ltd.     

4种营养状况评价方法的比较及意义

目的　分析比较身高标准体重法、离差法、体质指数、体质指数校正法等四种方法在大学生营养评价中的意义。　方法　随机抽取 187名大学生 ,用四种方法对其营养状况进行评价 ,结果用单因素卡方分析法和Ridit分析法比较。　结果　用四种方法评价同一群体大学生的营养状况时 ,其结果的差异有显著意义。　结论　作为 18～ 2 2岁的大学生 ,以身高标准体重法的评价结果更为客观 ;由于这一年龄段的发育水平影响其评价结果 ,因此 ,以发育水平分组评价时 ,可能更有意义     

称重法、回顾法和食物频率法评估人群食物摄入量的比较

目的比较称重法、回顾法和食物频率法在评估人群食物摄入量的差异和相关性。方法2002年中国居民营养与健康调查中同时使用称重法、24 h回顾法和食物频率法进行膳食调查的15-75岁的居民23 198名(男11 107名,女12 091名)。称重法入户称量调查对象全家过去3 d在家吃的所有食物重量;24 h回顾法回顾调查对象过去3 d每天在家及在外所消费的食物的种类和数量;食物频率法调查对象过去1年内所摄入的33类食物及油盐和调味品的摄入频率及摄入量。结果回顾法和称重法调查得出的平均每天食物摄入量比较接近;除水果和饮酒量外,其他食物摄入量与称重法的差异均在10％以内;低估和高估的个体的比例均比较少,60％以上的个体食物摄入量的估计值在称重法的±25％以内;回顾法得出的个体食物摄入量与称重法的结果均呈中高度正相关,相关系数在0．58-0．88之间。食物频率法得出的摄入频率较高的食物与称重法比较接近,米及其制品、面及其制品、其他谷类、豆类、蔬菜、坚果和油的摄入量与称重法的相对差异均在15％以内;食物频率法低估和高估的比例均比较高,一般在称重法的±25％以内的个体不足50％;食物频率法得出的食物摄入量与称重法呈低中度相关,相关系数在0．08-0．76之间。结论以称重法为标准的验证结果支持称重法修正24 h回顾法在群体以及个体中进行食物摄入量的调查。食物频率法可以反映群体及个体的食物摄入情况,尤其对消费频率较高的食物,比较适用研究膳食和健康的关系。     

Linkage analysis of Alzheimer's disease with methods using relative pairs

Four relative-pair methods for detecting genetic linkage were applied to familial Alzheimer's disease data. Results obtained using an extended Haseman-Elston test and a weighted rank pairwise correlation test, which both use information from all relative pairs, were consistent with previously published likelihood results and appear to be more powerful than affected sib pair methods. © 1993 Wiley-Liss, Inc.     

Repeated significance tests of linear combinations of sensitivity and specificity of a diagnostic biomarker

A sequential design is proposed to test whether the accuracy of a binary diagnostic biomarker meets the minimal level of acceptance. The accuracy of a binary diagnostic biomarker is a linear combination of the marker's sensitivity and specificity. The objective of the sequential method is to minimize the maximum expected sample size under the null hypothesis that the marker's accuracy is below the minimal level of acceptance. The exact results of two‐stage designs based on Youden's index and efficiency indicate that the maximum expected sample sizes are smaller than the sample sizes of the fixed designs. Exact methods are also developed for estimation, confidence interval and p‐value concerning the proposed accuracy index upon termination of the sequential testing. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.     

两种评估方法对高危儿粗大运动发育结局和脑性瘫痪预测效度的比较

目的研究全身运动(general movements assessment,GMs)质量评估和0~1岁20项神经运动检查法(20项检查法)对高危儿粗大运动发育结局和脑性瘫痪预测效度的比较。方法按照纳入标准,选择30名高危儿为研究对象,在不安运动阶段(足月后9周龄~5月龄)进行GMs评估以及20项检查法各1次。随访至纠正年龄1周岁以后根据临床表现以及采用Peabody运动发育量表2(Peabody Developmental Motor Scale 2,PDMS-2)评估粗大运动发育结局以及是否为脑性瘫痪。计算两种方法的敏感度、特异度、阳性预测值、阴性预测值以及Kappa值进行比较。结果纳入的30例研究对象中,脑性瘫痪3例(10%)例,粗大运动发育落后5例(16.7%)(包括3例脑性瘫痪),25例(83.3%)正常。GMs对粗大运动发育落后的预测效度:敏感度80.0%,特异度96.0%,阳性预测值80.0%,阴性预测值96.0%;20项检查法对粗大运动发育落后的预测效度:敏感度100.0%,特异度92.0%,阳性预测值71.4%,阴性预测值100.0%。GMs对脑性瘫痪的预测效度:敏感度100.0%,特异度92.6%,阳性预测值60.0%,阴性预测值100.0%;20项检查法对脑性瘫痪的预测效度:敏感度100.0%,特异度85.2%,阳性预测值42.9%,阴性预测值100.0%。两种方法的Kappa值=0.59。结论在足月后9周龄~5月龄阶段,两种方法对粗大运动发育结局的预测各有优势,GMs对脑瘫预测更优,两种评估方法有中等程度的一致性。     

Sources of validity evidence for an internal medicine student evaluation system: an evaluative study of assessment methods

Background  Medical students' final clinical grades in internal medicine are based on the results of multiple assessments that reflect not only the students' knowledge, but also their skills and attitudes.
Objective  To examine the sources of validity evidence for internal medicine final assessment results comprising scores from 3 evaluations and 2 examinations.
Methods  The final assessment scores of 8 cohorts of Year 4 medical students in a 6-year undergraduate programme were analysed. The final assessment scores consisted of scores in ward evaluations (WEs), preceptor evaluations (PREs), outpatient clinic evaluations (OPCs), general knowledge and problem-solving multiple-choice questions (MCQs), and objective structured clinical examinations (OSCEs). Sources of validity evidence examined were content, response process, internal structure, relationship to other variables, and consequences.
Results  The median generalisability coefficient of the OSCEs was 0.62. The internal consistency reliability of the MCQs was 0.84. Scores for OSCEs correlated well with WE, PRE and MCQ scores with observed (disattenuated) correlation of 0.36 (0.77), 0.33 (0.71) and 0.48 (0.69), respectively. Scores for WEs and PREs correlated better with OSCE than MCQ scores. Sources of validity evidence including content, response process, internal structure and relationship to other variables were shown for most components.
Conclusion  There is sufficient validity evidence to support the utilisation of various types of assessment scores for final clinical grades at the end of an internal medicine rotation. Validity evidence should be examined for any final student evaluation system in order to establish the meaningfulness of the student assessment scores.     

Quality of life: status and change (QLsc) reliability,validity and sensitivity of a generic assessment approach tailored for diabetes

The aim was to review the psychometric properties of a generic strategy for assessing status and change in quality of life (QLsc) partly tallored for patients with insulin-dependent diabetes mellitus. Quality of life was defined as perceived well-being and life satisfaction, globally as well as within key domains and functions. The strategy has been developed iteratively and, thereby, proven psychometrically satisfactory across groups and settings. Seventy-three consecutive outpatients were examined in 1988, after a period on multiple injection treatment by insulin pen; 66 were re-examined in 1990. In 1988 and 1990, perceived well-being and life domain status were self-rated. Life domain changes attributed to pen treatment were rated retrospectively in 1988 and subsequent general changes over 2 years rated similarly in 1990. Shortened parallel ratings were performed by significant others. Series of cross-sectional and longitudinal analyses yielded convincing reliability, validity and sensitivity evidence of various kinds for all ratings, irrespective of rater—self or significant other. As expected, a consistent correlational pattern emerged between status self-ratings, suggesting the better/worse off in one sense, the better/worse off in other senses assessed. Moreover, congruent change linkages, suggesting the greater change for the better/worse according to the one type, the greater change for the better/worse according to the other one, were also salient. Fourteen persons with less congruence in the disparate, but parallel change rating parameters appeared to be in a critical disease phase, applying reaction formation or denial like defence mechanisms. In conclusion, the entire cohesive strategy also functioned well in the current setting. It may probably be applied in search for other vulnerable sub-groups and in analyses of coping strategies. It offers rich analytic options especially in evaluational contexts. The study outcome may stimulate development of methodology within this field.This work has been supported by grants from the County of Jönköping and the Swedish Medical Research Council, project numbers B88/89-27X-08327-01A/02B and K88/89/90-27P-08466-01AK/02B/03A/04B.     

Comparison of obesity classification methods among college students

The purpose of this study was to compare obesity classification methods (body mass index (BMI)), abdominal girth (AG), and body fat percentage (BF%)), among college students. College students (n = 5943) completed an objective fitness assessment, where height and weight (used to calculate BMI), AG, and BF% (using Bioelectrical Impedance Analysis) were assessed. Correlation and chi-square tests for independence analyses examined relationships between variables and obesity classification methods; and, the sensitivity and specify of BMI using AG and BF% were calculated. Significant correlations were found between BMI and BF% for men (r = 0.775, p < 0.001) and women (r = 0.849, p < 0.001); BMI and AG for men (r = 0.868, p < 0.001) and women (r = 0.858, p < 0.001); and, BF% and AG for men (r = 0.749, p < 0.001) and women (r = 0.767, p < 0.001). There were significant associations between BMI, AG, and BF% for both sexes. Obesity categorization differed significantly between methods. In men and women, respectively, 47.6% and 44.1% classified as normal weight based on BF% were classified as overweight or obese based on BMI (Men: χ2 = 1547, p < 0.001; Women: χ2 = 1127, p < 0.001). In men and women, respectively, 48.3% and 24.0% classified as normal based on AG were classified as overweight or obese using BMI (Men: χ2 = 1274, p < 0.001; Women: χ2 = 996, p < 0.001). Comparing AG and BF%, 25.1% of men and 18.6% of women classified as normal based on AG were classified as overweight or obese using BF% (Men: χ2 = 1412, p < 0.001; Women: χ2 = 421, p < 0.001). Obesity classification differed significantly between methods, and BMI demonstrated relatively poor predictive value with respect to obesity classification. Thus, caution should be applied when using BMI to diagnose obesity among college students.     

Variance estimation and confidence intervals for the standardized mortality ratio with application to the assessment of a cancer screening program

The effect of a cancer screening program can be measured through the standardized mortality ratio (SMR) statistic. The numerator of the SMR is the observed number of deaths from the screened disease among participants in the screening program, whereas the denominator of the SMR is an estimate of the expected number of deaths in these participants under the assumption that the screening program has no effect. In this article, we propose a variance estimator for the denominator of the SMR when this expected number of deaths is estimated with Sasieni's method. We give both a general formula for this variance as well as formulas for specific disease incidence and survival estimators. We show how this new variance estimator can be used to build confidence intervals for the SMR. We investigate the coverage properties of various types of confidence intervals by simulation and find that intervals that make use of the proposed variance estimator perform well. We illustrate the method by applying it to the Québec Breast Cancer Screening program.     

长期铅暴露后果的研究进展

  目的  比较3种不同职业健康风险评估方法,为铅酸蓄电池企业更好的开展职业健康风险评估工作提供依据。  方法  对江苏省某铅酸蓄电池企业进行职业卫生调查,检测作业岗位铅烟/尘、硫酸浓度及铅接触作业工人血铅,采用国际采矿与金属委员会（ICMM）职业健康风险评估法、健康危害化学物控制要素法（COSHH Essentials）、综合指数法对铅酸蓄电池企业关键岗位的职业危害因素进行健康风险评估,比较标准化后的风险比值,以血铅异常率为参照,选择评估结果更准确的风险评估方法。  结果  当有害因素浓度在1/2限值～限值之间时,和膏与加酸岗位,3种方法评估结果完全一致,均为中等风险;当有害因素浓度高于限值时,铸板、磨片、分刷片与焊接岗位COSHH Essentials法和综合指数法评估结果为高风险;当有害因素浓度低于1/2限值时,球磨与涂板岗位评估结果不一致,综合指数法评估结果与血铅异常率的中等风险相对应。  结论  综合指数法适用于有害因素任意现场检测浓度情况下的职业健康风险评估。