Evaluation of three retrospective exposure assessment methods

OBJECTIVE: To evaluate three methods for assessing retrospective exposures of acrylonitrile workers. METHODS: Three methods used to develop historical exposure estimates for a retrospective cohort mortality study of acrylonitrile workers were considered. The first method was deterministic, incorporating estimates of the impact of changes that took place in the workplace. The second method used the ratio of the mean of the measurements for three similar jobs to estimate a fourth similar job. The third method was based on the development of homogeneous exposure groups (HEG). Estimates of acrylonitrile exposure were developed using these three methods and compared with measurement means (observed means) across three categories of airborne exposure concentrations (<0.5, 0.5-0.99 and >or=1 p.p.m.) and three categories based on the number of measurements used to develop the estimate (<10, 10-29 and >or=30). RESULTS: The correlation between the estimates and the observed values was about 0.65 for all three methods. Estimates using the deterministic method tended to overestimate the observed means by 17%, but the number of estimates was not above or below the observed means more often than expected. There was no statistically significant relationship between the exposure estimates and the acrylonitrile concentration in the air or the number of measurements used to develop the estimates. The estimates averaged within 60% of the observed means when concentrations were above 0.5 p.p.m. and 25% regardless of the number of measurements on which the estimates were based. Estimates from the ratio method were randomly distributed above and below the observed means and averaged 70% above the observed means. The air concentration did not affect the performance of the method, although above 1 p.p.m. the estimates were within 40% of the observed means. The number of measurements comprising the estimates was related on a relative scale to the performance of the method. Exposure estimates using the HEG method were neither greater nor less than the observed means more often than what was expected. The method did better as concentration and the number of measurements increased. The estimates were within 60% of the means at >0.5 p.p.m. and for all measurement categories. Overall, there was no statistically significant difference between the estimates derived from the three estimation methods. CONCLUSIONS: All methods performed reasonably well, but the deterministic and HEG methods appeared to develop estimates closer to the observed means for concentrations >0.5 p.p.m., regardless of the number of measurements.     

New techniques in nutritional assessment: body composition methods.

New techniques in air-displacement plethysmography seem to have overcome many of the previous problems of poor reproducibility and validity. These have made body-density measurements available to a larger range of individuals, including children, elderly and sick patients who often have difficulties in being submerged underwater in hydrodensitometry systems. The BOD POD air-displacement system (BOD POD body composition system; Life Measurement Instruments, Concord, CA, USA) is more precise than hydrodensitometry, is simple and rapid to operate (approximately 1 min measurements) and the results agree closely with those of hydrodensitometry (e.g. +/- 3.4% for estimation of body fat). Body line scanners employing the principles of three-dimensional photography are potentially able to measure the surface area and volume of the body and its segments even more rapidly (approximately 10 s), but the validity of the measurements needs to be established. Advances in i.r. spectroscopy and mathematical modelling for calculating the area under the curve have improved precision for measuring enrichment of 2H2O in studies of water dilution (CV 0.1-0.9% within the range of 400-1000 microliters/l) in saliva, plasma and urine. The technique is rapid and compares closely with mass spectrometry (bias 1 (SD 2) %). Advances in bedside bioelectrical-impedance techniques are making possible potential measurements of skinfold thicknesses and limb muscle mass electronically. Preliminary results suggest that the electronic method is more reproducible (intra- and inter-individual reproducibility for measuring skinfold thicknesses) and associated with less bias (+12%), than anthropometry (+40%). In addition to these selected examples, the 'mobility' or transfer of reference methods between centres has made the distinction between reference and bedside or field techniques less distinct than in the past.     

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     

Some nutritional habits of a group of overweight and obese women

The aim of the project was to research the nutritional habits of overweight and obese women. The group under investigation consisted of 100 randomly chosen women from the region of Malopolska. Their diet turned out to be inconsistent with proper nutrition. The majority of the women (80%) confessed not to reducing the cholesterol intake. About 50% of the researched did not pay attention to the food products containing the salt and sugar. Fast-food products and fat meat were commonly. The women were aware that their diet was not proper from the nutritional point of view.     

Preliminary assessment of nutritional status in a group of persons with visual impairments

Twenty-five legally blind subjects were visited in their own homes in an attempt to make a preliminary assessment of their nutritional status. Standing heights and weights were taken. Twenty-four hour recalls of the previous day's dietary intake were taken on three different days and some demographic data was also collected. Not one of the subjects consumed a diet in accordance with that recommended by Canada's Food Guide to Healthy Eating. The poorest food group consumed was Milk Products with 96% of the subjects consuming less than the minimum recommended. Caloric values of the diets consumed appeared to be low yet body weights were very high. Physical inactivity is a possible contributing factor.     

The use of a dynamometer in nutritional assessment.

Standard anthropometric techniques may be unreliable in patients with subcutaneous edema or dehydration. In order to circumvent this dilemma, 98 male subjects were studied utilizing a hand-held dynamometer in conjunction with other nutritional assessment techniques. Following a nutritional assessment using anthropometric measurements, patients were characterized as being well-nourished or malnourished using three definitive measures: percentage of ideal body weight, triceps skinfold, and midarm muscle circumference. Once malnutrition was assessed, no attempt was made to distinguish between marasmus, hypoalbuminemia, or mixed marasmus types of malnutrition. A correlation matrix done between the two groups revealed no statistically significant correlation between any of the measured parameters. Analysis of variance revealed statistically significant correlations between patients in both groups (independent variables) with respect to midarm muscle circumference and dynamometer reading in the dominant arm (dependent variables). Further validation of this technique is required before it can become a standard component of nutritional assessment.     

Prognostic ability of nutritional assessment methods in surgical cancer patients

To identify patients at high-risk for post-operative infections, several methods have been proposed, including prognostic nutritional index (PNI), instant nutritional assessment (INA) and nutritional assessment (NA). Weight loss (WL) has also been related to post-operative morbidity. We have evaluated the prognostic ability of PNI, INA, NA and WL in a prospective study carried out in 94 patients affected by gastro-intestinal malignancy, who underwent major surgery. Post-operative infections occurred in 26 (27.7%) patients. PNI, INA and NA identified classes of patients with a progressive risk of septic complications. To determine the prognostic ability of PNI, INA, NA and WL, sensitivity, specificity, Youden index and predictive values were evaluated. All methods had a Youden index greater than one, with a positive predictive value ranging from 0.33 to 0.36. Since all the methods studied showed a similar predictive ability, it seems reasonable to identify the high-risk surgical patient by using weight loss in association with those nutritional parameters derived from routine hospital laboratory tests.     

Validation of a food frequency questionnaire for nutritional calcium intake assessment in Italian women

OBJECTIVE: To evaluate a food frequency questionnaire assessing calcium intake in women. DESIGN:: Estimates of calcium intake from the food frequency questionnaire were compared with those from 14 day records from 206 Caucasian women aged 25-75 y in Siena, Italy. SUBJECTS: Subjects were randomly recruited from the residents list of the city of Siena, Italy. Of the 250 initially recruited, 39 did not meet the inclusion criteria or failed to complete the diet record and five outliers were excluded before the statistical analysis on the basis that their diet record was unlikely to represent habitual intake. RESULTS: Mean dietary calcium intakes were 829+/-255 (s.d.) mg/day from the questionnaire and 818+/-260 (s.d.) mg/day from the diet record. The mean difference in intake by the two methods (-11.3+/-116.4 mg/day) did not differ significantly from zero. Specificity in classifying women consuming less than 800 mg/day calcium was 86.6%, and sensibility in classifying women consuming more than 800 mg/day calcium was 89.4%. CONCLUSIONS: The food frequency questionnaire could be used in epidemiological studies to assess calcium intake in young to elderly women. The specificity in identifying low calcium intake subjects makes it useful also as an educational tool in diet counselling and for prescribing calcium supplementation.     

三种培养法在妊娠晚期孕妇B族链球菌感染筛查中的应用

目的分析核酸环介导恒温扩增法(LAMP)、增菌培养法及直接培养法在妊娠晚期孕妇B族链球菌(GBS)感染筛查的效能。方法选取海南西部中心医院2020年1月-2020年6月常规检查的500例孕妇为研究对象,分别进行增菌培养法、LAMP法、直接培养法筛查,并以增菌培养法为参考方法,比较LAMP法、直接培养法的检验效能;利用乳胶凝集试验和管家基因测序确定GBS阳性孕妇的血清型和基因序列分型(ST),并用纸片扩散法检测GBS药敏性;统计所有孕妇围产结果。结果500例孕妇的样本中增菌培养法检出68例GBS阳性,阳性率为13.60%,肛直肠拭子GBS检出阳性率82.35%(56/68)要高于阴道拭子的36.76%(25/68)(P<0.05);以增菌培养法为标准,直接培养法和LAMP法灵敏度分别为82.35%、100.00%,特异度分别为100.00%、98.84%,一致性Kappa值分别为0.890、0.959;乳胶凝集实验共检出8种GBS血清型,前5位分别为III型、V型、Ia、Ib、II型;管家基因测序共发现14个ST型,前5位的分别为ST19、ST17、ST862、ST12、ST10;68株GBS对青霉素G、头孢唑林、氨苄西林、万古霉素等敏感;GBS阳性孕妇的胎膜早破、宫内感染、早产、胎儿窘迫及新生儿感染的发生率显著升高。结论LAMP法在妊娠晚期孕妇GBS检测的准确性与增菌培养法一致,且更加快速便捷,一旦发现感染要及时用药,提高产妇和新生儿的生活质量。     

Biochemical assessment of the nutritional status of low-income pregnant women of Mexican descent.

Biochemical parameters of nutritional status were investigated in 300 women of Mexican descent during the first and second trimesters of pregnancy. Blood samples were obtained from the women during clinic visits, and measurements were made of serum iron, hemoglobin, hematocrit, serum protein, and transferrin saturation. Additionally, the nutritional status of seven vitamins was determined either by direct assay of the vitamin levels in blood or by measurement of erythrocyte enzyme stimulation. Thiamin and riboflavin were also determined in causal urine samples. Very few women, 8% or less, were classified as being low or deficient in hemoglobin, serum protein, iron, transferrin saturation, vitamin C, carotene, vitamin A, or vitamin B12. Thirty-one percent had low or deficient hematocrit values according to the guidelines used. Folic acid was the most prevalent vitamin deficiency, with 69% of the women having low or deficient serum levels. Based on the erythrocyte enzyme stimulation tests, 22% of the women were low or deficient in thiamin, 29% were low or deficient in riboflavin, and 9% were deficient in pyridoxine. None of the women had a low urinary excretion of thiamin, but 8% had excretion values of riboflavin below the acceptable level. Fewer deficiencies of thiamin and serum folic acid were observed in women taking vitamin and mineral supplements than in those who were not.     

Health technology assessment of three screening methods in Switzerland

OBJECTIVE: To describe the level of health technology assessments for three screening methods in Switzerland. METHODS: Analysis of documents and expert opinions on mammography screening, ultrasound examinations during normal pregnancy, and screening for prostate-specific antigen (PSA) with a focus on services provided, recommendations, formal regulations, national papers, projects, and formal assessments. RESULTS: Preventive services are explicitly recommended by the Swiss federal law on health insurance. Two routine ultrasound examinations during normal pregnancy as well as PSA analysis for men over 40 years of age on medical indication are covered by basic health insurance. Mammography screening every 2 years has been covered since 1997 for women over 50 years. A systematic screening program for mammography exists in the western part of Switzerland, and a nationwide program is planned. However, a national program may not come into being until a quality assurance program for evaluation is established, and a nationwide fee for reimbursement-to include all costs of such a program-is accepted by providers and insurers. CONCLUSION: According to the Swiss health insurance law, the effectiveness of mammography screening and ultrasound examinations during normal pregnancy have to be proven. Systematic evaluation of these screening methods is in preparation. PSA is not part of current evaluation. It can be concluded that health technology assessment in Switzerland is now required by law for several medical services. However, limited financial and personnel resources as well as the lack of disease registers may hamper progress in the near future.     

Interrelationship of some selected nutritional parameters relevant to taste for salt in a group of college-aged women

Students in a women's college were investigated for taste acuity for salt, discrimination of salt concentrations in food, and anthropometrical (the body mass index, and systolic and diastolic blood pressures) and biochemical nutritional parameters (blood hemoglobin, plasma zinc, plasma copper, plasma vitamin A, plasma retinol-binding protein, urinary sodium, urinary potassium, urinary magnesium, urinary calcium and urinary zinc). Among 95 students who participated in the test for discrimination of salt concentrations, which was repeated 6 times with 5 different test samples, only 43 (45.3%) committed no mistakes. The detection threshold for taste of salt was significantly associated with neither the discriminability of salt concentrations nor any biochemical parameters. Levels of plasma zinc (PZn), urinary zinc (UZn) and plasma vitamin A (VA) were lower in the present subjects than in those reported previously. The rate of correct discrimination (RCD) was significantly correlated with PZn and VA positively, and with urinary sodium (UNa) and urinary potassium (UK) negatively. In the factor analysis to investigate the interrelationship of nutritional parameters, 6 factors with significance were extracted, among which factors 3 and 4 were related to RCD. Factor 3 had large loadings on VA, plasma retinol-binding protein (RBP) and RCD, and factor 4 was positively loaded on UNa and UK and negatively on UZn and RCD. In the stepwise multiple regression analysis (RCD being the dependent variable), significant independent variables selected were VA, UK, PZn, systolic blood pressure and UNa. From these results, the college-aged women's failure in discriminating salt concentrations in food was likely to be related to vitamin A inadequacy, mild Zn deficiency and excessive intakes of Na and K.     

The value of nutritional assessment methods in surgical patients living in Saudi Arabia

Several methods have been propsed to assess nutritional status of patients in relation to post-operative complications including instant nutritional assessment (INA) and prognostic nutritional index (PNI). Weight loss (WL) has also been related to post-operative morbidity. A prospective study was conducted to evaluate the prognostic ability of INA, PNI and WL in 300 patients affected by major and semi-major surgeries. Post-operative sepsis occurred in 28 (9.3%) patients. Of the 300 patients studied, 91 (30.2%) had WL 10%; 12 patients were septic. Of the 28 septic patients indentified, 24 (85.7%) were within the high-risk group as identified by PNI characterisation. When both serum albumin and total lymphocyte count were abnormal, sepsis rate was 100%. All methods had a Youden index greater than one. Therefore, WL should be the first parameter assessed, and if WL is > 10%, then INA can be used to assess the patient further.     

Problems of nutritional assessment in the community.

The present paper explores the problems associated with assessment of nutritional status in the community and reviews the literature related to this subject. The first problem is one of terminology, since a logical first step before assessment is screening, which identifies characteristics known to be associated with dietary or nutritional problems. Its purpose is to differentiate individuals who are at high nutritional risk or have poor nutritional status. There are certain factors which should alert the primary health care team to the fact that nutritional intake may be reduced and that risk of malnutrition is increased. These include disease condition, functional disabilities, inadequate or inappropriate food intake, poor dentition or difficulty swallowing, polypharmacy, alcoholism, depression, poor social circumstances or recent discharge from hospital. Patients suffering from these factors need to be identified so that screening becomes a routine part of their medical treatment. At-risk groups include the elderly, the chronically ill, those with cancer and neurological disorders, post-surgical patients and children with developmental disabilities. In the community, practice and community nurses see the majority of at-risk patients and should carry out screening. A number of screening tools have been developed for community use. Most are aimed at the elderly population, but there are others designed to assess nutritional risk in children with developmental disabilities and the general population. These are reviewed and problems of content and validity identified. Some problems associated with nutritional assessment are also reviewed.     

3种风险评价方法在化学毒物职业危害风险评价与管理中的应用与分析

目的探讨3种职业病危害风险评价方法在某炼油污水处理场化学毒物风险评价的应用,为建立职业病危害风险评价和管理提供科学参考。方法根据某污水处理场现场检测、职业卫生学调查资料,运用MES法、半定量风险矩阵法、风险指数法对化学毒物职业病危害风险进行计算分类,综合考虑分类结果提出整改措施。结果3种风险评估方法对化学毒物风险评价结果存在差异,经整改后,除氨（P=0．08）外,个体或工作场所苯、甲苯、二甲苯、非甲烷总烃、溶剂汽油、硫化氢浓度均显著降低（P〈0．05）。结论3种风险评估方法在对化学毒物职业危害风险评价实际应用中能有助于企业发现高风险危害,但仍需建立更具体评价指标体系。     

Chylomicron triglyceride clearance: comparison of three assessment methods

Three indirect methods for assessing chylomicron-triglyceride clearance were compared in 12 normolipidemic men. Oral and intravenous fat tolerance tests and a duodenal fat perfusion were performed in each subject by standard methods. Mean values for postprandial lipemia (2.27 +/- 1.8 mmol), Intralipid half-life (13.7 +/- 5.2 min), and chylomicron-triglyceride half-life (4.5 +/- 2.6 min) were similar to corresponding values reported previously for normolipidemic men. The sample correlation coefficient (r) was 0.84 between oral and intravenous fat-tolerance tests, 0.84 between the oral fat-tolerance test and the duodenal-perfusion method, and 0.82 between the intravenous fat-tolerance and the duodenal perfusion methods. All three methods showed a strong correlation between chylomicron-triglyceride clearance and fasting triglyceride concentrations. These findings indicate that the oral and intravenous fat-tolerance tests and the duodenal-perfusion method yield qualitatively similar assessments of chylomicron-triglyceride clearance in normolipidemic men.     

Use of a computer tutorial on nutritional assessment by three different groups of health professions students

A computer tutorial on nutritional assessment was developed and used with three different groups of health professions students. Complete data were available for 45 nursing students, 36 physician assistant students, and 68 physical therapy students. Overall for the three groups there was a significant increase (p < 0.0001) from pretest to posttest scores. This increase was not significantly different among the groups, suggesting that a single computer tutorial can be used effectively to teach basics of nutritional assessment to different groups of health professions students and allow sharing of cost for computer instruction among programs.     

妊娠期糖尿病3种筛查方法的探讨

目的:对孕妇糖尿病3种筛查方法进行对比分析,以简化传统的筛查方法,使之更加适应孕妇普查需要。方法:对孕妇作空腹静脉血糖、末梢血糖、血清糖化蛋白测定,并作50 g OGTT测静脉及末梢血糖。阳性者再作75 g OGTT。统计资料时将75 g OGTT异常及GDM者列为异常组,其他为正常组,两者进行对比分析。结果:筛查206例,50 g OGTT异常者30例,75 g OGTT异常者13例(GDM 2例占0.97%,G IGT 11例占5.39%),孕妇空腹时末梢血糖高于静脉血糖,服糖后无此现象。血清糖化蛋白检测GDM敏感度为92.31%,有61.65%孕妇在正常值之下。50 g OGTT静脉血糖异常者67例(37.72%),末梢血糖异常者153例(79.21%)。结论:测定孕妇血清糖化蛋白可作为孕妇糖尿病的初筛。更加适宜筛查的需要。异常者再作50 g OGTT比做50 g末梢血糖筛查更经济、合理,若阳性再做75 g OGTT以确诊。     

Clinical nutritional assessment: a perspective

The negative implications of hospital malnutrition have been wall documented and demand recognition. Nutritional assessment consists of anthropometric, biochemical, clinical, and dietary indexes and forms the objective basis for diagnosis of protein-calorie malnutrition as well as the mechanism by which nutritional adequacy of aggressive alimentation (enteral and parenteral) is evaluated. In the ideal setting, extensive nutritional assessment consists of numerous tests, measurements, and continuous monitoring performed by a specialist whose primary area of expertise is nutritional assessment and clinical nutritional support. In the absence of this service, significant protein-calorie malnutrition should be suspected if the patient has recently lost weight exceeding 10 per cent of usual weight, has a serum albumin of less than 3.5 gm. per deciliter, or exhibits any pathologic state with nutrition-related manifestations.