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At least 127 records · Page 7Linked to original sources
PubMed2001

Intra- and inter-tester reliability and reference values for isometric neck strength.

BACKGROUND AND PURPOSE: Age- and sex-specific reference values for neck strength based on reliable measurements in the upright position are lacking. The aim of the present study was to determine intra- and inter-tester reliability and age- and sex-specific reference values for isometric neck strength in extension, flexion and lateral flexion in sitting position measured with the David Back Clinic 140 (DBC 140) equipment. METHOD: The reliability of the DBC 140 equipment was investigated in 30 healthy volunteers and reference values were obtained from 101 healthy men and women. RESULTS: The reliability study showed that neck strength measured with the DBC 140 equipment has almost perfect intra- and inter-tester reliability (ICC values between 0.85 and 0.97). The mean value of the first in a series of three measurements was the highest for all three test leaders and for almost all directions. Results from the reference value study showed that gender is a much more important determinant of neck strength than age, body weight or body mass index (BMI). Neck strength in women was, on average, 55% of that in men, and when adjusted for body weight or BMI, the percentages were 70% and 59%, respectively. In all directions observed, neck strength decreased by approximately 20% from age 25 to 64 years. CONCLUSIONS: Measurements of neck strength taken in upright position with the DBC 140 equipment have almost perfect intra- and inter-tester reliability and justify the use of this test procedure. The use of the first measurement in a test series can be recommended for use in clinical practice since it was shown to be the maximal test value and thus, had a very low intra-tester difference. The use of reference values for neck strength when evaluating patients with neck disorders needs to take gender into account.

Adult↗
PubMed2007

Hematologic reference values for African American children and adolescents.

Anemia is prevalent among African American children. When evaluating pediatric patients for anemia, clinicians refer to the normative hematological reference values in reference textbooks. These reference values are used in spite of evidence that healthy African American people of all ages have average hemoglobin concentrations from 0.5 to 0.73 g/dl below those of Whites. In an earlier study, using samples from 2,161 healthy African American children from 2 to 18 years old, we found a statistically significant difference (P < 0.0001) in the mean hemoglobin value for each age group as compared to reference normative mean hemoglobin values. Here we present the results of a comparative analysis of the data set from our previous study and the data set from the National Health and Nutrition Examination Surveys III (NHANES III) 1988-1994. We found no statistically significant difference between these data sets with respect to the hemoglobin values for any age or sex group, confirming that African American children and adolescents have lower mean hemoglobin values than do Whites. Use of the reference hemoglobin values presented here will help prevent the misdiagnosis of anemia in African American children and thereby minimize unnecessary hematological workups and treatment.

Adolescent↗
PubMed2000

Haematology reference values for healthy elderly blacks residing in Harare, Zimbabwe.

OBJECTIVES: To determine reference values for elderly blacks and to compare them to those in use in local hospitals and in other countries in the region. DESIGN: Cross sectional study. SETTING: Sekuru Kaguvi Hospital, Harare, Zimbabwe. SUBJECTS: 151 persons of age 45 years or more. MAIN OUTCOMES MEASURES: Haematological parameters investigated were Hb, Hct, MCV, MCH, MCHC, Plt, RBC and WBC. RESULTS: 56 males and 95 females tok part in the study. RBC, Hb and Hct mean values were significantly higher (p=0.004, p<0.001 and p<0.001, respectively) in males than in females. However, no significant differences between sexes were found in WBC (p=0.137), MCHC (p=0.273), MCV (p=0.090) and MCH (p=0.074). Platelet counts were significantly higher (p=0.040) in females [median (Q1, Q3): 251 (117, 478)] than in males, 226 (122, 251). These haematogological vales were notably different compared with those in current use in local hospitals. The mean values obtained for each index were comparable with those obtanied in other countries in the same region (Southern Africa) as Harare. The reference values for the elderly blacks are presented. CONCLUSION: The importance of gender and population specific reference values cannot be over emphasised. The reference values obtained in the current study should be appropriate for evaluating haematological test results in elderly blacks in Zimbabwe.

Aged↗
PubMedDate not supplied

[Environmental and biological reference values of plant pesticides].

A wide range of studies concerned with the definition of environmental and biological reference values for plant pesticides is reviewed. All phases of data production are critically assessed, including sampling, sample preparation and analysis, choice of population, statistical analysis and expression of results. The importance of the studies for the definition of reference values useful in the sectors of environmental hygiene and occupational toxicology is also examined. Most of the studies were based on American populations, though work on reference values has also recently been done by Italian authors, particularly the SIVR, which has published data on 3,5,6-trichloro-2-pyridinol and ethylenethiourea in urine. Because the number of the studies is small and more detail about variables is needed, the lists of reference values, given separately for American and Italian populations, also include proposals and attempts at definition of reference values. When available, biological reference values (BRV) are given separately for adults and children, emphasising the greater intake of the infant population due to higher food intake per unit body weight and greater exposure to contaminants present in the domestic environment. BRVs for plant pesticides generally depend on factors such as smoking, wine consumption and diet, major sources of residue intake for the human population.

Biomarkers↗
PubMed2005

Flow cytometric assay in peripheral blood of dogs--reference values for leukocytes from Brazilian beagles.

Use of domestic reference values in the flow cytometry analysis is known to improve its accuracy by integrating local variations as gender, race and age. Up to date application of flow cytometry in veterinary medicine has been limited to describe the percentual values just for peripheral lymphocytes subsets of blood. We now report establishment of reference values for a wide range of proportional and absolute numbers of peripheral blood leukocytes, including T cells subsets, B cells, monocytes and eosinophils, applicable to the healthy population of Beagles in Brazil and other regions with similar demographic characteristics. Normal reference values were also established to estimate the gender-related differences. This information will provide clinical aid in the evaluation of immunologic status as well as standard values for experimental animals of dogs from Brazil and other similar regions.

Animals↗
PubMed2002

Reference value of presenile human hematocrit and geographical factors.

The aim of this study was to provide a scientific basis for a unified standard of the reference value of healthy presenile human hematocrit in China. We studied the relationship between the reference values of healthy presenile human hematocrit, tested according to Wintrobe's laws, and five geographical factors. It was found that altitude is the most important factor affecting the reference value of the hematocrit. As the altitude gradually increases, the reference value of the hematocrit also increases. The relationship is quite significant. By using the method of stepwise regression analysis, two multivariate regression equations were deduced: Y1 = 39.7 + 0.00328X1 + 0.00169X2 + 0.00117X5 +/- 2.3, Y2 = 38.8 + 0.00275X1 + 0.000578X2 -0.00298X4 +/- 2.2 In these equations, Y1 is the reference value of presenile men's hematocrit (%); Y2 is the reference value of presenile women's hematocrit (%); X1 is altitude (m); X2 is the average annual hours of sunshine (h); X4 is the average annual temperature (degrees C), and X5 is the average annual precipitation (mm). If the geographical index values in a particular area in China are known, the reference value of presenile human hematocrit in this area can be calculated approximately by means of the regression equations.

China↗
PubMed1994

Respiratory muscle strength in the elderly. Correlates and reference values. Cardiovascular Health Study Research Group.

Maximal inspiratory pressure (MIP) was assessed in 4,443 ambulatory participants of the Cardiovascular Health Study, 65 yr of age and older, sampled from four communities. Maximal expiratory pressure (MEP) was also measured in 790 participants from a single clinic. Positive predictors of MIP included male sex, FVC, handgrip strength, and higher levels of lean body mass (or low bioelectric resistance). Negative predictors were age, current smoking, self-reported fair to poor general health, and waist size. Both participant and technician learning effects were noted, but there was no independent effect of race, hypertension, cardiovascular disease, or diabetes. A healthy subgroup was identified by excluding current smokers, those with fair to poor general health, or an FEV1 less than 65% of predicted. Mean values determined from the healthy group were 57/116 cm H2O (MIP/MEP) for women, and 83/174 for men. Lower limits of the normal range (fifth percentiles) were 45 to 60% of the mean predicted values. The reference equations derived from this group of healthy 65 to 85-yr-olds may be used by pulmonary function laboratories and respiratory therapists who evaluate the respiratory muscle strength of elderly patients.

Aged↗
PubMed2006

Post-bronchodilator spirometry reference values in adults and implications for disease management.

RATIONALE: International guidelines promote the use of post-bronchodilator spirometry values in the definition and severity classification of chronic obstructive pulmonary disease. However, post-bronchodilator reference values have not yet been developed. OBJECTIVES: To derive reference values for post-bronchodilator forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC, and to compare these reference values with locally derived and existing pre-bronchodilator reference values. METHODS: Based on a random sample of a general adult population, 2,235 subjects (70% of invited subjects) performed spirometry with reversibility testing. A reference population of healthy never-smokers constituted 23% of the study population (n=515). Reference values for median and lower-limit-of-normal pre- and post-bronchodilator lung function and bronchodilator response were modeled using quantile regression analyses. MAIN RESULTS: The reference population had equal proportions of men and women in the age range 26-82 yr. Both FEV1 and FVC decreased with age and increased with height. FEV1/FVC decreased with age, although this trend was not statistically significant for men after bronchodilatation. Linear models gave the best overall fit. Lower-limit-of-normal post-bronchodilator FEV1/FVC exceeded 0.7 for both sexes. Post-bronchodilator prediction equations gave higher predicted FEV1 and FEV1/FVC than both locally derived and existing pre-bronchodilator equations. The bronchodilator response decreased with age. CONCLUSIONS: The present study is the first to develop reference values for post-bronchodilator lung function. Post-bronchodilator prediction equations can facilitate better management of patients with chronic obstructive pulmonary disease by avoiding falsely high FEV1% predicted with a subsequent underestimation of disease severity.

Adult↗
PubMed1993

[New criteria for evaluating the findings of clinical laboratory tests. New reference values for ascertaining biological effects of various environmental factors].

In this article new reference values and methodology of clinical laboratory tests useful as guidelines for providing health instruction on health effects of various environmental factors are suggested. Two different processes are developed as the methods for determining the reference values, which are comprised of three elements. One of the processes is based solely on the analysis of the relationship between a certain environmental factor and the result of a certain laboratory test (Unifactor method). The other process includes also analysis of other confounding factors in addition to analysis by the unifactor method (Multifactor method). Basic to these statistical analyses is the comparison of distribution of pertinent data among individuals with and without the factor. Using one of the reference values, 'X1 (unifactor method) or x1 (multifactor method)', we can discriminate those individuals who will be affected by an environmental factor with the highest reliability. Another reference value, 'X2 (unifactor method) or x2 (multifactor method)', on the other hand, can be used to identify those individuals in whose case the health effect of the factor must be closely considered. In some cases, a third reference value, 'X0 (unifactor method) or x0 (multifactor method), can also be determined. This value corresponds to the lowest or highest limit of the range that would not be associated with the factor. We believe that many health promotion activities may become more effective through the utilization of the results of health examinations that include assessment of total and environmental factors.

Clinical Laboratory Techniques↗
PubMed1992

Reference values for the study of low doses.

At present, the quantitative differences between environmental exposure and occupational exposure to toxic metals are steadily decreasing, it becomes important to establish reference values of the tests used for biological monitoring. However, the word 'reference values' is often used inappropriately and in particular its significance is often confused with that of 'limit values' or 'normal values'. The term reference values defines the levels of the biological indicators in the general population which are not occupationally exposed. It is necessary to refer to these values in order to compare the data obtained through biological monitoring programmes in workers and in groups of the general population which are presumed to be exposed. The most essential aspects for identifying reference values for toxic metals, using a rigorous methodology, are taken into consideration and in particular, the requisites needed for identifying the subjects which must be included in the reference groups are also examined. The modalities for using reference values for individual subjects as well as for groups are then discussed and the main points of research which must be faced in the near future regarding reference values are highlighted.

Environmental Monitoring↗
PubMed1998

Hematological indices in an older population sample: derivation of healthy reference values.

Factors affecting hematological values were explored, and healthy reference values were estimated from a cross-sectional survey of a population (n = 4433), ages 49 years or more, residing permanently in a defined geographic region. Nursing home residents were excluded. Details of medication use and medical history were obtained by interview, and participants were asked to return after an overnight fast for blood sampling. The participation rate was 82.4%, of whom 88.4% provided a fasting blood sample. Hemoglobin, hematocrit, and erythrocyte counts were higher in men, whereas platelet counts were higher in women. Statistical associations between each hematological index and smoking, alcohol intake, use of certain drugs, chronic disease, and high creatinine values were tested by unpaired t-tests. Separate reference groups were defined for each hematological index by excluding subjects with any of the factors found to be of importance. The resulting reference values are particularly appropriate for evaluating hematological test results in older individuals.

Aged↗
PubMed2006

Revised and new reference values for arsenic, cadmium, lead, and mercury in blood or urine of children: basis for validation of human biomonitoring data in environmental medicine.

Reference values for environmental pollutants in the German population are established continuously by the Human Biomonitoring Commission of the German Federal Environmental Agency. The reference values (defined as 95th percentile) are usually derived from results of the German Environmental Surveys (GerES). However, current reference values for children are lacking since GerES II conducted in 1990/92 and additionally the first German Environmental Survey on Children (GerES IV) will not be finished until the end of 2006. As an interim solution, the commission derived in 2005 reference values for children aged 6-12 years from a survey performed in south-west Germany in 2002/03 (508 children) and the pilot study for GerES IV 2001/2002 (252 children). A new reference value of 15 microg/l for children was derived for arsenic in urine. The reference values for cadmium in whole blood (0.5 microg/l) and for cadmium in urine (0.5 microg/l) were confirmed. The following reference values were lowered: for lead in blood from 60 to 50 microg/l, for mercury in whole blood from 1.5 to 1.0 microg/l and for mercury in urine from 1.4 to 0.7 microg/l.

Animals↗
PubMed2001

New reference values for routine blood samples and human neutrophilic lipocalin during third-trimester pregnancy.

Reference values are usually based on blood samples from healthy men or non-pregnant women. Blood samples from pregnant women may be compared with these reference values. Correct references for pregnancy can be extremely important for clinical decisions such as ablatio placentae, appendicitis, premature rupture of membranes and preeclampsia. Previous studies of normal variations during third-trimester pregnancy are incomplete. Blood samples during pregnancy weeks 33, 36 and 39 as well as 1-3 h postpartum were collected from pregnant women with dietary iron supplement and at least one previous pregancy without a history of hypertension or preeclampsia. When the sampled values were compared with the present reference values from men and non-pregnant women, the following differences were found during normal pregnancy: Haemoglobin and ferritin were reduced, CRP was slightly elevated, WBC (white blood cell count) and HNL (human neutrophilic lipocalin) were elevated during pregnancy and significantly increased postpartum. Albumin was reduced. ALT and AST were slightly elevated and GGT was unchanged during pregnancy. ALP, D-dimer and fibrinogen were elevated. Uric acid increased during the third trimester and thrombocyte count decreased. Separate reference values for pregnant women are essential for correct diagnostic decisions during third-trimester pregnancy. Elevated levels of D-dimer do not necessarily indicate ablatio placentae. A diagnosis of progressive preeclampsia cannot be based on increasing uric acid levels and reduced platelet count in a stable clinical condition. HNL signals activation of neutrophilic granulocytes and can thereby offer a helpful tool for diagnosing infection during pregnancy and postpartum.

Blood Chemical Analysis↗
PubMed1991

[Reference values for spirometry exemplified by FVC and FEV1 parameters--comparison of normal values of the Pathophysiology of Respiration Section and the European Society for Coal and Steel].

Reference values published by the Section Pathophysiology of Breathing in the Society for Pulmology and Tuberculosis of the GDR and reference values of European Community for Coal and Steel (EGKS) were compared on example of FVC and FEV1. It was found a relative well accordance of reference values of FVC and FEV1 in younger and middle-aged men of a height from 160-200 cm (between -5 to +15%). In women with a body height of 150 to 200 cm a well correlation for FVC and FEV1 is also given (-10 to +10%). Reference values are showing a more important difference with increasing age and independent of sex. There are problems concerning the reference values in male and female lower than 155 cm body height.

Adult↗
PubMed2002

[Body mass index. Reference values for 0-45-year-old Danes].

INTRODUCTION: Our aim was to establish body mass index (weight/height2 [kg/m2], BMI) reference values for 0- to 45-year-old Danes. MATERIAL AND METHODS: A national sample that was used to generate the current Danish height and weight reference (29,106 measurements in 1965-1977; age 0-21 years; sample I). Four samples from Copenhagen (3391 measurements in 1981-1985; age 7-45 years; samples II and III and 2608 measurements in 1991-1994; age 6-45 years; samples IV and V). With the LMS method for smoothing the curves, Danish BMI reference values by age and sex were constructed from samples I and II. BMI values from two recently examined, but smaller, Danish cohorts (samples IV and V) were compared with the reference values to assess the secular trend in BMI. RESULTS: The Danish BMI reference values are presented graphically. Graphs can be downloaded from http://www.paediatri.dk. In the more recently examined samples, the mean BMI was significantly increased in children and adolescents (SD score 0.19, P = 0.0007), but unchanged in young adults (SD score 0.01, P = 0.49). DISCUSSION: For clinical purposes, we recommend comparison of the BMI of Danish children and adolescents with the present Danish reference values and new internationally based cut-off values. The BMI of Danish adults should be compared with the WHO cut-off values. Cut-off values or national or internationally used BMI reference values can be used for research, depending on the purpose.

Adolescent↗
PubMed2004

Reference values for peripheral blood lymphocyte phenotypes applicable to the healthy adult population in Switzerland.

OBJECTIVES: Use of domestic reference values is known to improve the accuracy of flow cytometric analysis by integrating local variation due to race, gender, and age. In the absence of previously published estimates, we now report establishment of reference values for a wide range of peripheral blood lymphocyte phenotypes applicable to the healthy adult population in Switzerland and other regions with similar demographic characteristics. METHODS: A representative sample population was recruited from among well characterized local blood donors (n = 70) and quantitative multiparametric flow cytometry used to estimate absolute and proportional values for a range of T-, B-, and NK-cell subsets, including those associated with activation and maturity. Distribution-free methods were then applied to generate 95% reference values and to estimate the significance of gender and age-related differences. RESULTS: Reference values were obtained for the absolute and proportional levels of total CD3(+) T cells (536-1787 cells/microL, 54.90-84.03%), helper CD4(+) T cells (309-1139 cells/microL, 32.53-62.88%), cytotoxic CD8(+) T cells (137-823 cells/microL, 11.55-38.60%), activated CD3(+) T cells expressing CD25 (7-94 cells/microL, 0.50-5.95%), CD38 (102-554 cells/microL, 5.98-26.80%), HLA-DR (18-186 cells/microL, 1.25-9.68%) or CD38/HLA-DR (4-52 cells/microL, 0.30-2.30%), activated CD4(+) T cells expressing CD25 (7-52 cells/microL, 0.33-2.80%), CD38 (69-547 cells/microL, 6.13-32.20%), HLA-DR (11-55 cells/microL, 0.80-4.43%) or CD38/HLA-DR (4-22 cells/microL, 0.30-1.35%), activated CD8(+) T cells expressing CD25 (0-12 cells/microL, 0.00-0.69%), CD38 (13-124 cells/microL, 0.93-7.03%), HLA-DR (6-108 cells/microL, 0.33-6.38%) or CD38/HLA-DR (2-47 cells/microL, 0.13-2.68%), naive CD4(+) T cells expressing CD45RA(+)/CD62L(+) (84-761 cells/microL, 9.48-41.88%), naive CD8(+) T cells expressing CD45RA(+)/CD62L(+) (42-360 cells/microL, 3.68-19.23%), memory CD4(+) T cells expressing CD45RO(+) (247-807 cells/microL, 16.50-42.15%), memory CD8(+) T cells expressing CD45RO(+) (72-377 cells/microL, 3.78-22.80%), B-cells expressing CD19 (72-460 cells/microL, 4.70-19.13%) or CD20 (66-529 cells/microL, 4.63-21.00%), total CD3(-)/(CD16(+)/CD56(+)) NK-cells (77-427 cells/microL, 5.35-30.93%), and activated NK-cells expressing CD25 (0-10 cells/microL, 0-0.50%) or HLA-DR (3-99 cells/microL, 0.20-7.28%). CONCLUSION: It is anticipated that availability of localized reference values for an extended range of peripheral blood lymphocyte phenotypes should supplement previously published reference values and enhance the utility of flow cytometric analysis undertaken in Switzerland.

Adult↗
PubMed1985

Reference values for exercise tests with continuous increase in load.

Reference values for exercise tests with continuous increase in load are presented. The exercise tests were performed on an electrically braked bicycle ergometer by 188 randomly selected Swedes of both sexes who were between 20 and 79 years of age. The reference values are related to sex, age (in decades) and weight and classified in decreasing levels of exercise capacity. Reference values for systolic blood pressure at different work loads are also given.

Adult↗
PubMed1993

Subject-based reference values in thyroid function tests.

To evaluate the diagnostic value of subject-based reference values in thyroid function tests, we compared intra-individual and inter-individual variation. Five specimens were collected over a period of 2 weeks from each of 47 normal subjects, 29 women and 18 men, aged 20-47 yrs. T4, FT4, T3, and FT3 were assayed by RIA, and TSH by a sensitive immunoradiometric assay. One-way ANOVA for each test was statistically significant for a main subject effect, indicating that the subjects differed in their personal mean values for the thyroid function tests (T4, P < 0.01; FT4, P < 0.05; T3, P < 0.01; FT3, P < 0.05; TSH, P < 0.01). The ratio value (intra- over inter-individual variation) was T4, 0.41; FT4, 0.60; T3, 0.53; FT3, 0.63; TSH 0.36. The data indicate that conventional reference values are insensitive when compared to subject-based reference intervals in assessing the thyroid status of a given subject. Reactivity of the thyroid to the stimulation of endogenous TSH was assessed by the ratio delta FT 3/delta TSH in TRH stimulation tests. A positive correlation between basal FT3 and delta FT3/delta TSH (r = 0.566, P < 0.05) indicates that the thyroid with higher reactivity to TSH secretes more daily thyroid hormone. Negative correlation between basal TSH and delta FT3/delta TSH (r = -0.536, P < 0.05) means that a subject with lower reactivity of the thyroid needs a higher basal TSH level to compensate. The thyroid reactivity to TSH may be an important determinant for the individuality of the pituitary-thyroid axis.

Adult↗