Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Reference Values”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed1991

[Reference values of dipolar electrocardiotopography of the QRS complex].

Reference values of dipolar electrocardiotopogram of ventricular depolarization are presented. The data for establishing reference values in the McFee-Parungao lead system were obtained by manual processing of 145 records of healthy subjects (64 women, 81 men) in the age range of 11-72 years, and for the Frank lead system by automatic processing of 123 records of healthy subjects (54 women, 69 men) aged from 9 to 72 years. The obtained values of the X, Y, Z coordinates of the end points of QRS instantaneous vectors recorded at 10 ms intervals were processed by means of a biomathematical model in the form of activation areas on the spherical image surface. Electrocardiotopograms were represented in the form of discrete spherical image surface in the shape of a rectangle (11 lines, 24 columns). For each point of this matrix the value of relative frequency (probability) of its occurrence in activated state in the healthy population is given.

Adult↗
PubMed1998

Reference values for 24-hour ambulatory blood pressure monitoring based on a prognostic criterion: the Ohasama Study.

Although reference values for ambulatory blood pressure (ABP) monitoring have been investigated in several population studies, these values were derived from cross-sectional observations and were based merely on the statistical distribution of blood pressure values. Therefore, we conducted a prospective cohort study to identify reference values for 24-hour ABP in relation to prognosis. We obtained measurements of 24-hour ABP for 1542 subjects (565 men) aged 40 years and over in a general population of a rural Japanese community and then followed-up their survival status. There were 117 deaths during the follow-up period (mean, 6.2 years). The association between baseline 24-hour ABP values and mortality, examined by the Cox proportional hazards regression model adjusted for possible confounding factors, showed a better fit with a second-degree equation than with a first-degree equation. On the basis of the results of this analysis, we identified the following reference values as the optimal blood pressure ranges that predict the best prognosis: 120 to 133 mm Hg for systolic blood pressure and 65 to 78 mm Hg for diastolic blood pressure. 24-Hour ABP values >134/79 mm Hg and <119/64 mm Hg were related to increased risks for cardiovascular and noncardiovascular mortality, respectively. This is the first report to propose reference values for 24-hour ABP based on a prognostic criterion.

Adult↗
PubMed1989

Health-based reference values of the Mini-Finland Health Survey: 1. Serum gamma-glutamyltransferase, aspartate aminotransferase and alkaline phosphatase.

The reference values for gamma-glutamyltransferase (GT), aspartate aminotransferase (ASAT) and alkaline phosphatase (AFOS) activities in serum have been produced on the basis of measurements done in the Mini-Finland Health Survey. A representative sample of all Finns aged 30 years or over comprised 8000 persons, of whom 99.2% participated in the actual health survey. Every effort was made to obtain reference values for the healthy ambulatory population. Three separate health-derived selection criteria were used to obtain such reference values for the above-mentioned enzymes: those based on the available literature, with minor modifications, the recommendations published by the Committee on Reference Values of the Scandinavian Society for Clinical Chemistry and Clinical Physiology, criteria that were obtained after subgroup comparisons of the obtained data, where all the factors affecting the enzyme levels were identified. The recommendations of the Expert Panel on Theory of Reference Values (1987) were strictly adhered to in the statistical analyses. The distribution of the serum activity of GT was very skewed. The overall intervals for men and women were 5.1-1460 and 4.7-748 U/l, respectively. The frequency distributions could be transformed to the normal ones logarithmically. The 95% inner reference intervals for GT in the three groups were 7-76, 7-65, and 8-57 U/l for men and 6-35, 6-30 and 6-32 U/l for women, respectively. For ASAT the full intervals of the enzyme levels in serum were 2.6-770 U/l for men and 8.3-172 U/l for women. After logarithmic transformation the respective reference intervals in the three selection groups were 14-42, 14-40 and 13-39 U/l for men and 13-33, 12-31 and 13-33 U/l for women. The full intervals of AFOS were 47.5-2755 and 5.4-816 U/l for men and women, respectively; after the logarithmic transformation the reference intervals of the three selection groups were 98-267, 97-254 and 97-264 U/l for men and 77-265, 75-231 and 75-250 U/l for women, respectively.

Adult↗
PubMed2003

Reference values for change in body mass index from birth to 18 years of age.

UNLABELLED: Body mass index (BMI) has become the measure of choice for determination of nutritional status during the paediatric years, as in adults. Recently, several cross-sectional BMI childhood reference values standards have been published. In order precisely to evaluate childhood nutritional interventions, reference values allowing for the evaluation of changes in BMI values are also needed. For the first time, such reference values can be presented based on 3650 longitudinally followed healthy Swedish children born full term. The reference values for the change in BMI are given as the change in BMI standard deviation scores. The reference values are given as means of mathematical functions adjusting for gender, age of the child and the length of the interval between two measurements for interval lengths of 0.25 to 1.0 y before 2 y of age and of 1 to 5 y between birth and 18 y. The usefulness of the reference values is proved by a graph that forms a part of a clinical computer program; the -2 to +2 standard deviation range of the predicted change in BMI can be computed for an individual child and drawn in the graph as an extended support for clinical decision-making. CONCLUSION: For the first time this communication gives access to BMI growth rate values that can be used both in research and in the clinic to evaluate various interventions, be they nutritional, surgical or therapeutic.

Adult↗
PubMedDate not supplied

Reference value of young people's erythrocyte sedimentation rate and altitude.

The purpose of this paper is to provide a scientific basis for a unified standard of the reference value of young people's erythrocyte sedimentation rate (ESR) in China. The reference values of healthy young people's ESR were collected according to the Wintrobe method, and the relationship between the reference value of young people's ESR and altitude was tested in this paper. It was found that the reference value of young people's ESR decreases when the altitude gradually increases, and the relationship is significant. The method of mathematical univariate regression analysis was used to deduce two regression equations: Y(1) = 10.92-0.00183X +/-2.59 and Y(2) = 18.58-0.00319X +/-4.37. If the altitude value of a particular area of China is known, the reference value of young people's ESR can be calculated by means of the regression equations. Furthermore, depending on the altitude, China can be divided into three districts: Qingzang, Central and Eastern districts.

Adolescent↗
PubMed1995

[Reference values of laboratory tests: a useful and important epidemiologic contribution of the Centers for health tests].

Since 1969 the Centre for Preventive Medicine in Nancy has been carrying out health examinations of the eastern region of France (Lorraine, Champagne-Ardenne). The clinical chemists at the Centre of Preventive Medicine have made a great contribution to the concept and the description of biochemical reference values for which the transferability to other health centres must be verified. Knowledge of reference values and biological variations facilitates the interpretation of weak modifications of biological constituents which are observed in preventive medicine. Reference values can be used to compare two populations (comparing reference values between to two) or to compare an individual observed value to the reference values obtained in the various population groups. In the long term, these reference values could become a useful education tool for patients coming for health examination. It should be possible for each subject to follow, throughout his life, the evolution of his biological constituents and to detect any deviation towards a pathology.

Diagnostic Tests, Routine↗
PubMed2002

Swedish population-based longitudinal reference values from birth to 18 years of age for height, weight and head circumference.

UNLABELLED: This study aimed to update growth reference values for height, weight and head circumference in order to reflect the changes in body size in the Swedish population during the past two decades. The data came from a large longitudinal growth study on 3650 full-term healthy Swedish children who were born between 1973 and 1975. All of these 1801 girls and 1849 boys had longitudinal data for height and weight from birth to final height. Comparison with previous Swedish growth reference values based on children born between 1955 and 1958 revealed that there have been secular changes in body size. For instance, at 18 y of age, the updated height and weight reference values are 180.4 cm for males and 167.7 cm for females, i.e. 1.9 cm taller and 5.7 kg heavier for males and 2.3 cm taller and 3.4 kg heavier for females compared with the previous reference values. CONCLUSION: These new growth reference values provide current national standards for growth monitoring and evaluation since the year 2000.

Adolescent↗
PubMed2004

Energy and nutrient dietary reference values for children in Europe: methodological approaches and current nutritional recommendations.

The Expert Group on the Methodological Approaches and Current Nutritional Recommendations in Children and Adolescents was convened to consider the current situation across Europe with regard to dietary recommendations and reference values for children aged 2-18 years. Information was obtained for twenty-nine of the thirty-nine countries in Europe and a comprehensive compilation was made of the dietary recommendations current up to September 2002. This report presents a review of the concepts of dietary reference values and a comparison of the methodological approaches used in each country. Attention is drawn to the special considerations that are needed for establishing dietary reference values for children and adolescents. Tables are provided of the current dietary reference values for energy and for the macronutrients, vitamins, minerals, trace elements and water. Brief critiques are included to indicate the scientific foundations of the reference values for children and to offer, where possible, an explanation for the wide differences that exist between countries. This compilation demonstrated that there are considerable disparities in the perceived nutritional requirements of European children and adolescents. Although some of this diversity can be attributed to real physiological and environmental differences, most is due to differences in philosophy about the best methodological approach to use and in the way the theoretical approaches are applied. The report highlights the main methodological and technological issues that will need to be resolved before harmonization can be fully considered. Solving these issues may help to improve the quality and consistency of dietary reference values across Europe. However, there are also considerable scientific and political barriers that will need to be overcome and the question of whether harmonization of dietary reference values for children and adolescents is a desirable or achievable goal for Europe requires further consideration.

Adolescent↗
PubMed1998

Establishment of reference values for endocrine tests. I: Cushing's syndrome.

BACKGROUND: For diagnostic tests used in the evaluation of patients with Cushing's syndrome, well defined reference values were lacking in our laboratory. In the present study, we established reference values based upon test results of 50 subjects recruited from the general population. METHODS: We studied 50 subjects not suspected of having Cushing's syndrome, equally distributed according to sex and age between 20 and 69 years. In addition to 24 h urinary excretion of free cortisol for two days, a low-dose (1 mg) overnight dexamethasone suppression test, a corticotropin releasing hormone stimulation test (CRH test) and a high-dose (7 mg) intravenous dexamethasone suppression test were performed. Reference values are given as the observed range. RESULTS: There was considerable intra-subject variation in 24 h urinary cortisol excretion which could not be merely attributed to incompleteness of the urine collection. The following reference values were established: 24 h urinary free cortisol excretion: 15-145 nmol/24 h; overnight dexamethasone suppression test: cortisol on day 2 < 50-230 nmol/l; CRH test: cortisol increase 15-289%, ACTH increase 36-12.100%; high-dose, intravenous dexamethasone suppression test: cortisol after 7 h < 50-97 nmol/l; cortisol after 24 h < 50-50 nmol/l. There were no significant effects of age on any of the parameters studied. Apart from higher basal ACTH plasma concentrations in men, no sex differences were observed. CONCLUSION: We established reference values for tests that can be useful in the evaluation of patients with possible Cushing's syndrome.

Adrenocorticotropic Hormone↗
PubMed2004

Reference values for arterial blood gases in the elderly.

OBJECTIVES: We present reference values for arterial blood gas measurements for persons > 70 years old. At the same time, we wish to examine how different criteria for exclusion from the reference sample with regard to previous smoking and various comorbidities might influence reference values. METHODS: After first screening a random sample of the general elderly population by postal questionnaire, we selected 146 men and women without respiratory disease, significant dyspnea, symptomatic heart disease or hypertension, or current smoker status. Arterial blood samples were drawn from subjects while in the supine position. RESULTS: The mean (SD; lower limit of normal) PaO(2) and arterial oxygen saturation (SaO(2)) for men was 77.0 mm Hg (9.1; 62.0) and 95.3% (1.4; 93.0), respectively, and for women was 73.5 mm Hg (8.4; 59.6) and 94.8% (1.7; 92.0). Mean (SD; upper limit of normal) PaCO(2) was 39.4 mm Hg (3.3; 44.8) for both sexes. None of the blood gas variables were associated with age, smoking history, or presence of various comorbidities. CONCLUSIONS: The reference values for PaO(2) and SaO(2) in elderly persons are sex specific but age independent. Ex-smokers and persons with nonpulmonary comorbidities who do not have significant respiratory symptoms need not be excluded from the reference sample for arterial blood gases.

Age Factors↗
PubMedDate not supplied

Using reference values in pulmonary ventilation studies.

The aim of this study was to examine the discriminating power of six widely used, or recently introduced, reference values in the interpretation of pulmonary ventilation (FVC and FEV1) in occupational health surveys. These six reference values were applied to a sample of 400 Italian males; 200 of the sample were foundry workers and the other 200 were workers who were not occupationally exposed to dusts; 50% of each group were smokers. The relationship between the reference values and their capacity to discriminate between the workers occupationally exposed to dusts and the workers who smoked in each group was evaluated. The results showed very significant differences among the various reference values. Generally speaking these differences may be determined by the different selection criteria of the subjects under study, or may be a result of the different characteristics of the population included in the various studies. Our conclusions show the need for a critical approach to the use of reference values, particularly during screening tests.

Adult↗
PubMed1999

[Reference values for IGF-I, IGFBP-1, IGFBP-3 and osteocalcin in healthy children in Zaragoza].

OBJECTIVE: Our aim was to estimate reference values for basal serum concentrations of insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-1, IGFBP-3 and osteocalcin in healthy children of Zaragoza. PATIENTS AND METHODS: The reference population consisted of healthy children between 0 and 14 years of age with normal weight and height and living in the metropolitan area of Zaragoza (Spain). It was a transversal study. Immunoradiometric assays were used to determine basal serum IGF-I, IGFBP-1, IGFBP-3 and osteocalcin concentrations. Reference values and ranges were estimated according to the recommendations of the International Federation of Clinical Chemistry. RESULTS: Reference values have been classified according to age, sex and pubertal stage. IGF-I, IGFBP-1, IGFBP-3 and osteocalcin concentrations differ during the pubertal period according to age. There are differences in IGF-I, IGFBP-3 and osteocalcin levels between prepuberty and puberty and differences in IGF-I and osteocalcin levels among the pubertal stages. Sex did not influence IGF-I or IGFBP-1 concentrations and there were punctual differences in IGFBP-3 and osteocalcin levels between girls and boys. CONCLUSIONS: Sincere there are differences in IGF-I, IGFBP-1, IGFBP-3 and osteocalcin reference values according to age, sex, pubertal stage and immunoassays, it is necessary to establish the reference values for each population and laboratory in accordance with these parameters.

Adolescent↗
PubMedDate not supplied

Hematologic and clinical chemistry reference values in red lories (Eos spp.).

We established reference ranges for three hematologic and 15 clinical chemistry parameters of 40 clinically healthy birds of the genus Eos. The following species were included to the study: Eos histrio (n = 19), Eos squamata (n = 8), Eos bomea (n = 5), Eos reticulata (n = 4), Eos cyanogenia (n = 4). Detailed information concerning methodology, which is often missing in papers dealing with reference values, is included. As far as possible, data are compared with literature, and some thoughts on obvious deviations are given. The problem of establishing reference values in rare species is reviewed.

Animals↗
PubMed1999

Comparison of lung-function reference values.

OBJECTIVE: Lung-function reference values play an important role in medical surveillance examinations of occupational and environmental respiratory diseases, in stipulation of preventive measures, in initiation of therapeutic measures, and in granting of benefits to which individuals with lung injuries or occupational lung diseases are entitled (e.g., bronchial asthma, pneumoconiosis, or farmer's lung disease). Prediction equations most widely used are based on studies performed more than 20 years ago and may not represent the findings obtained in today's population. METHODS: We recorded case histories and lung function values of 139 healthy subjects (spirometric and plethysmographic data, T(LCO)) and computed the differences of measured values minus predicted ones as recommended by different authors. RESULTS: The means of these differences can be seen as shifts in our group versus the theoretical (predicted) values of various authors. These shifts, the standardized mean values of residuals, and their probability as determined under the assumptions of the respective regression model and the number of subjects below the threshold limits are given. FVC, FEV1, and FEV1%FVC show mostly good agreement with the recommendations by Crapo et al., Roca et al., Glindmeyer et al., Brändli et al., and Berger et al. Our IVC and FVC values do not differ significantly from each other. Normative flow-volume curve parameters of various authors deviate widely, however, and are not compatible with the values of our control group. Plethysmographically measured volumes (FRC, TLC, and RV) are only insufficiently reflected by Quanjer's reference equations. Measured T(LCO) and K(CO) show good agreement with the predictions of Cotes et al. [11] for females but display less concurrence with the predictions for males. CONCLUSIONS: Our results indicate that the ERS values of FVC, FEV1, and FEV1%FVC mainly applied in Europe should be verified. The much better-evaluated formulas of Brändli et al. are recommended. Furthermore, the age range between 60 and 70 years should be extrapolated from these formulas until better epidemiological data on lung function are available.

Adolescent↗
PubMedDate not supplied

Normal reference value of hemoglobin of infant girls and altitude in China.

BACKGROUND: The aim of this study was to supply a scientific basis for uniting the normal reference value standard of hemoglobin of Chinese infant girls. METHODS: A research study was carried out concerning the relationship between the normal reference value of 3,771 examples of hemoglobin of infant girls and altitude in 40 areas of China. Normal reference values of hemoglobin of infant girls were determined by hemoglobincyanide method. RESULTS: It was found that correlation of normal reference value of hemoglobin of infant girls and altitude was quite significant (r=0.545). By using method of univariate linear regression analysis, the following regression equation is inferred: Y = 112.9 + 0.008978X +/- 20.8. CONCLUSIONS: If altitude values are obtained in certain areas, normal reference value of hemoglobin of infant girls of this area can be reckoned by using the regression equation. Furthermore, depending on altitude, China can be divided into three districts as follows: Qingzang District, Central District, and Eastern District.

Altitude↗
PubMedDate not supplied

Total serum IgE: adult reference values in Valencia (1981-2004). Usefulness in the diagnosis of allergic asthma and rhinitis.

BACKGROUND: The reference values for total serum IgE are accepted to vary according to the geographical area involved. In 1981 we published the reference values for a donor population in the city of Valencia (Spain) and its metropolitan area. Since then, we have noted an increase in the prevalence of asthma and rhinitis in countries with a Western lifestyle, including Spain. AIM: To update the adult reference values for total serum IgE in the city of Valencia and its metropolitan area, and to determine their diagnostic usefulness in asthma and allergic rhinitis. MATERIAL AND METHODS: We studied two groups of 69 and 100 individuals each. One group comprised apparently healthy blood donors, as assessed by a routine blood bank study protocol and the application of a questionnaire to exclude perceived allergic or parasitic diseases, while the other group consisted of individuals with atopic respiratory disease (bronchial asthma and allergic rhinitis) studied in our service in the same time period (spring 2004). Total serum IgE was determined by the UniCAP method developed by Pharmacia. RESULTS: The geometric mean of total serum IgE among blood donors was 46.65 kU/l (95% CI: 15.5-77.8) versus 204.29 kU/l (95% CI: 93.3-515) among allergic subjects. The difference between the two groups was statistically significant. No significant difference was found between our donor sample in 1981 and the sample in the present study. Establishing an arbitrary cut-off point of 1.65 standard deviations (SD)(equivalent to 95 % of the donor population), we obtained a figure of > 183 kU/l whereby 44% of all allergic individuals presented a value below this cut-off point. To practical effects, these allergic patients behaved as low responders (LRs) in relation to total IgE, whereas the remaining individuals were high responders (HRs) in relation to total IgE. CONCLUSIONS: Our data confirm the current validity of the reference values obtained in 1981, which continue to be significantly different from those of the UniCAP method for Swedish donors. The population of allergic subjects can be divided into two subgroups: subjects with total IgE levels similar to those of the donors, which we refer to as LRs, and which represent 44% of all allergic subjects, and a second subgroup with total IgE values above those of the donors (HRs), who would therefore be the only subjects that would be identified by individual serum IgE study.

Adult↗
PubMedDate not supplied

Reference values for arm muscle area, arm fat area, subscapular skinfold thickness, and sum of skinfold thicknesses for American adults.

Reference values for the mid-upper arm muscle area, mid-upper arm fat area, subscapular skinfold thickness, and sum of triceps and subscapular skinfold thicknesses of American adults were developed from data collected by the National Center for Health Statistics during the first National Health and Nutrition Examination Survey, 1971 to 1974. The reference values were compared to other reference values derived from a similarly conducted cross-sectional survey of the American population, the Health Examination Survey of 1960 to 1962. These comparisons revealed that arm muscle area and subscapular skinfold thickness of men and arm muscle area of women continuously increase with aging from 18 to 74 yr; arm fat area and sum of skinfold thicknesses of men increase with aging from 18 to 34 yr but stabilize or decrease with further aging; and arm fat area, subscapular skinfold thickness, and sum of skinfold thicknesses of women increase with aging from 18 to 64 yr but decrease thereafter. As these parameters frequently change more than 20% over the period of a single decade, it is important that age be considered in nutritional evaluations based on anthropometric measurements. Changes in these four parameters with successive generations are also frequently large. Consequently, it is imperative that the reference values used in nutritional assessment protocols be updated at regular intervals.

Adipose Tissue↗
PubMed1998

Hematology and chemistry reference values for free-ranging harbor seals (Phoca vitulina) and the effects of hemolysis on chemistry values of captive harbor seals.

Most reported laboratory reference values for harbor seals (Phoca vitulina) are derived from captive seals, or stranded seals that have recovered from disease in marine mammal centers. This study established hematology and serum chemistry reference values for free-ranging harbor seals, using methods and that are current and readily available, and determined the effects of hemolysis on serum chemistry values of captive harbor seals. Blood samples were collected for hematologic and serum chemistry measurements from 14 clinically normal, adult male and female harbor seals and two juvenile harbor seals (approximate age 6 mo) captured in saltwater sloughs and estuaries near Moss Landing, California, USA. Values for amylase, globulin, and differential leukocyte count, not previously reported, were determined. In general, hematology and chemistry values in adults were similar to those reported for free-ranging and captive harbor seals, except for glucose, urea nitrogen, and lactate dehydrogenase (LDH) values, which were higher than those reported previously. Red blood cell counts in the two juveniles were higher than in adults and in young harbor seals studied previously. To determine the effects of hemolysis on serum chemistry values, two intensities of hemolysis were generated experimentally in blood collected from 11 harbor seals recovering from injuries or stranding at the Marine Mammal Center (Sausalito, California 94965, USA). Moderate hemolysis (++, 1 g/L hemoglobin, red-tinged) significantly increased LDH activity, whereas severe hemolysis ( , 2 g/L hemoglobin, cherry red) significantly increased total protein, albumin, calculated globulin, LDH, and total bilirubin and significantly decreased creatinine. The effects of hemolysis must be considered when chemistry results of harbor seals are interpreted.

Animals↗