PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Reference Values”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 847 records · Page 47Linked to original sources
PubMed1983

[Creatinine and urine density as reference values in biological monitoring].

Creatinine and density of urine as reference parameters in biological monitoring Since in practice biological monitoring with 24-hour urine samples is not possible, a reference parameter is required. In two different experimental models - for 10 days in 24-hour portions and for 1 day with spontaneous individual fractions - creatinine excretion, mean daily urine volume and urine density were measured quantitatively in 5 healthy human subjects not exposed to chemistry. In the 10-day model, coefficients of variation were: 8.7% for creatinine, 24.9% for mean urine volume and 11.7% for urine density. In the 1-day model, coefficients of variation were: 15.8% for creatinine, 51.0% for mean urine volume and 28.0% for density. This indicates that the results of the second model are considerably more expressive than those of the first. It can be concluded that creatinine is the most suitable reference parameter. Density is less suitable and mean urine volume least suitable.

Adult↗
PubMed1976

Blood reference values in the lamb (Na, K, Ca, P, Mg, Cu, Zn, Cl, urea, total proteins, creatinine, uric acid, alkaline phosphatase, aspartate amino transferase, cholesterol and hemoglobin).

We have determined sixteen blood chemical parameters in three month-old lambs and eleven in one and a half-month old ones. We have found that three of them were not affected by age: potassium, copper and proteins; seven were lowered: sodium, calcium, zinc, chlorine, inorganic phosphate, urea and cholesterol; one was enhanced : magnesium. These reference values will be used as a basis for further controls of the flocks.

Age Factors↗
PubMed1994

Establishment of creatinine clearance reference values for older women.

Age-adjusted reference ranges for creatinine clearance were determined in 279 women, ages 40-95 years, who were housed in a metabolic research unit and consumed a meat-free diet. Creatinine clearance, but not serum creatinine, declined with age by 0.63 mL/min per 1.73 m2 per year. Serum and urine creatinine concentrations, used to calculate clearances, were analyzed by a kinetic Jaffé procedure. In a subset of 100 subjects, fasting serum creatinine values averaged 8.3 +/- 5.2 (SD) mumol/L higher when measured by the kinetic Jaffé procedure than by an enzymatic method (creatinine PAP). The Cockcroft-Gault formula for estimating creatinine clearance from serum creatinine in women was validated, and the modification factor for the male equation was determined to be 0.84 (95% confidence interval 0.83-0.86) confirming the suggested 15% correction. A prediction formula derived from this population was similar in accuracy to the Cockcroft-Gault formula.

Adult↗
PubMedDate not supplied

[Reference values of pulmonary compliance (author's transl)].

Pulmonary compliance has been measured, using a classical method in 156 healthy subjects aged between 18 and 74 years, breathing spontaneously. Pulmonary compliance (ml-cmH2O-1) was related to height in meters (H) by an allometric relationship such as C = aHb. As b was not significantly different from three, than C/H3 ratio was studied. This ratio was not dependent on age so that it was possible to establish that, in men, C (ml-cmH2O-1) = 36.6 H3 (m) and in women, C (ml-cmH2O-1) = 33.3 H3 (m). These two relationships were significantly different. From these relationships and from reference values of pulmonary volumes, specific pulmonary compliance could be calculated but since confidence limits were very wide, their utilization is limited. Furthermore, it is difficult to apply specific compliance in respiratory impairment.

Adolescent↗
PubMed1998

Gestational age-dependent reference values for iron and selected proteins of iron metabolism in serum of premature human neonates.

The diagnosis and treatment of fetal and neonatal diseases requires knowledge of gestational age-dependent reference ranges for most laboratory values. It was the aim of the present study to establish reference values for serum iron, transferrin, ferritin and ceruloplasmin concentrations in premature neonates, thereby paying attention to the possible changes with gestational age. Blood samples were taken from 100 premature neonates within the first hour of life. Total serum iron, transferrin, ferritin and ceruloplasmin concentrations were determined, transferrin saturation was calculated. Newborns who developed a presumed oxygen radical disease of prematurity were excluded from the study (n = 37), because previous investigations could demonstrate significantly lower serum transferrin and ceruloplasmin concentrations in prematures suffering one of these disorders. Related to gestational age, only serum transferrin concentration showed a statistically significant increase and correlation (r = 0.47; p < 0.0001) with rising age. Although statistically not significant, even serum ferritin concentration increased with rising age of the neonates. None of the investigated laboratory values correlated with birth weight. Only ferritin showed a slight, but statistically not significant increase with higher body mass. We conclude that gestational age-dependent changes of serum transferrin levels must be considered in the judgement of fetal and neonatal diseases, whereas total serum iron and ceruloplasmin concentrations remain rather constant at least during the last weeks of gestation.

Birth Weight↗
PubMed1991

[Results of multicenter determination of preliminary reference values for albumin in urine of children and adults].

Reference intervals for urinary albumin were determined for adults (n = 358) using second morning urine (spontaneous). Percentiles were as follows: 90th percentile: 18 mg/l or 16 mg/g creatinine. 95th percentile: 28 mg/l or 24 mg/g creatinine. When related to volume, albumin values of children aged from 3 to 5 years (n = 60) were in the same range. When related to urinary creatinine, however, significantly higher values were obtained. The preliminary upper reference limit is 30 mg/g creatinine.

Adult↗
PubMed1996

Distribution of fasting serum insulin measured by enzyme immunoassay in an unselected population of 4,032 individuals. Reference values according to age and sex. D.E.S.I.R. Study Group. Données Epidémiologiques sur le Syndrome d'Insulino-Résistance.

As hyperinsulinaemia has been shown to be a risk factor for non-insulin-dependent diabetes, cardiovascular disease and hypertension, the measurement of serum insulin levels may provide an additional early screening test for these diseases. Biological assaying of insulin is now facilitated by the IMx-Abbott kit, an enzyme immunoassay which does not cross-react with proinsulin and thus provides more specific insulin determination than conventional methods. Fasting insulin concentrations were determined in a population of 4,032 men and women 30 to 64 years of age, all volunteers for a medical check-up. Concentrations were slightly higher for men in all age-classes (median values of 5.9 and 5.4 microU/ml respectively for men and women). Although significant differences were found in serum insulin concentrations between the four age-classes for men and women, there were no significant differences between the three age-classes for men up to 59 years (median: 5.8 microU/ml, 95th percentile 14.0 microU/ml) or between the two age-classes for women up to 49 years (5.2, 12.5). Fasting concentrations were increased above these age thresholds: men (6.4, 15.6), women (5.6, 14.0). The reference population consisted of 3,081 non-diabetic, glycosuria-negative subjects with a body mass index and glucose concentration lower than the 95th percentiles for their age and sex. The reference values for fasting insulin concentrations were: 1) women 30-49 years: median 5.1 microU/ml (95% confidence interval: 4.9-5.3), 95th percentile 11.2 microU/ml (10.9-11.9); and 2) men 30-64 years and women 50-64 years: median 5.6 microU/ml (5.4-5.7), 95th percentile 12.6 microU/ml (12.0-13.0).

Adult↗
PubMed2003

IgG subclass concentrations in certified reference material 470 and reference values for children and adults determined with the binding site reagents.

BACKGROUND: There is currently no international reference preparation for IgG subclass (IgGSc) quantification. This situation has led to calibration differences among assays and a variety of reference interval values with consequential difficulties in comparing results. We therefore evaluated IgGSc concentrations in Certified Reference Material 470 (CRM 470). METHODS: Pure, polyclonal IgG1, -2, -3, and -4 were prepared from a large serum pool for use as primary standards. The IgG mass in each preparation was calculated from amino-acid analysis data. IgGSc concentrations were assessed in CRM 470 by nephelometry with modern analytical techniques, using these reference preparations. Subsequently, IgGSc concentrations were measured in 380 healthy individuals (250 males and 130 females), and age-dependent reference intervals were established. RESULTS: IgGSc concentrations in CRM 470 were as follows: IgG1, 5028 mg/L; IgG2, 3418 mg/L; IgG3, 579 mg/L, and IgG4, 381 mg/L, with a total IgG concentration of 9406 mg/L, 2.83% below the certified total IgG value of 9680 mg/L. Age-dependent percentile curves for the four IgGSc were constructed using a Box-Cox transformation. Maximum median values were as follows: IgG1, 6.02 g/L at 11 years; IgG2, 3.45 g/L at 31 years; IgG3, 0.63 g/L at 17 years; and IgG4, 0.48 g/L at 14 years. No significant sex-related differences were observed. CONCLUSIONS: The correlation between the summation of individual IgGSc and separate measurements of total IgG concentrations was good and supports the accuracy of the results. The results are based on The Binding Site assays and should not be considered appropriate for other assays unless so demonstrated.

Adolescent↗
PubMed2000

Health-related quality of life measured by the EORTC QLQ-C30--reference values from a large sample of Swedish population.

The EORTC QLQ-C30 Health-Related Quality of Life (HRQOL) questionnaire was completed by 3069/3919 (78%) of a random sample of the Swedish population aged 18-79 years. The aims of the study were to provide normative data on the questionnaire and to investigate differences in HRQOL with respect to age, gender, sociodemographic characteristics and reported chronic health problems. Women had lower scores than men on all but one of the EORTC QLQ-C30 subscales and reported more chronic health problems. The oldest respondents (70-79 years) had a greater degree of impaired HRQOL than the other age groups, with one exception, 'Emotional functioning', in which they scored higher. Unemployed respondents reported poorer HRQOL than employed respondents. Higher income was associated with a more positive assessment of HRQOL. The results of the study present reference values for EORTC QLQ-C30 Version 3 questionnaire and clarify the influence of factors which should be taken into account when planning studies of HRQOL.

Adolescent↗
PubMed1975

Aspartate aminotransferase and alanine aminotransferase activities in plasma: statistical distributions, individual variations, and reference values.

The determination of frequency value (percentile limits) and the classification of the different variation factors allow us to define more and more homogeneous subpopulations as we use these factors for sorting. Using as our study population those persons coming to the Centre for Preventive Medicine, we were able to: (a) Describe and measure the significance and importance of physiological variations or of variations attributed to age--the latter largely related only to excessive weight, which it seems to us is often the case. (b) Establish a classification for variation factors; the recapitulatory table should be useful to clinical chemists in helping physicians interpret a laboratory test result that falls within the zone of incertitude. (c) Suggest a preliminary group of reference values for healthy subjects, to be used in interpreting a laboratory test in this way.

Adolescent↗
PubMed2004

Population-specific reference values for thyroid hormones on the Abbott ARCHITECT i2000 analyzer.

Reliable reference ranges are important in the interpretation of laboratory data, and it is incumbent on each laboratory to verify that the ranges they use are appropriate for the patient population they serve. The objective of this study was to determine population-specific reference ranges for thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3) and total triiodothyronine (TT3) on the Abbott ARCHITECT 12000 analyzer. For this study, we used human serum samples collected from a population in Castilla y León, Spain. Serum samples were collected from 304 individuals (male, n = 151; female, n = 153; age 12-94 years) representing outpatients (n=100), hospitalized patients (n = 104) and apparently healthy subjects (n = 100). Individuals taking any medications, with a history of thyroid disorder, or severe non-thyroidal illness were excluded from the study. For healthy subjects, the following reference intervals were determined: TSH, 0.51-5.95 mlU/l; fT4, 0.84-1.42 ng/dl (10.77- 18.21 pmol/l); fT3, 1.48-3.37 pg/ml (2.27-5.18 pmol/l); and TT3, 0.65-1.46 ng/ml (1.00-2.24 nmol/l). In this group, TSH and fT4 showed significant differences between men and women, but fT3 and TT3 did not. Conversely, fT3 and TT3 showed significant age-related differences, but TSH and fT4 did not. Within the outpatient group, no significant differences were seen between men and women for any of the hormones, but age-related differences were significant for fT3 and TT3. Within the hospitalized patient group, significant differences between men and women were found for TSH only, and age-related differences were significant for TSH, fT3 and TT3. Our findings are basically in accordance with previously published results for fT3, TT3 and TSH, but for fT4 our results differ from other data in the literature. This highlights the need for laboratories to confirm that the reference ranges they use are appropriate for the population they serve.

Adolescent↗
PubMed1995

[Reference values for trace elements in biological fluids].

The assessment of reliable reference ranges for the concentrations of elements in biological fluids is necessary to evaluate the risks deriving from occupational and environmental exposure. For the production of reference ranges in this field it is necessary to adhere to strict criteria for the selection of individuals, the procedures for sample collection, the control of analytical variability and the statistical treatment of results. The factors affecting analytical and biological variability of the concentrations to be determined, such as the route of absorption, the presence of sources of environmental pollution in certain areas of residence, physiological variables and life-styles, are discussed.

Animals↗
PubMed2006

[Reference values for thyroid 24 hours 123I uptake].

To establish references for thyroid 24 h 123I uptake value (TUV), we reviewed 475 patients who had free T4 and TSH dosages, and TUV measured 24h after the administration of 123I. The patients were separated in 3 groups: hyperthyroid, euthyroid and hypothyroid, according to thyroid hormone results. The mean and standard deviation (SD) of the TUVs were calculated for each group. We used the unpaired T test to compare the means and ROC curves to evaluate the best TUV to separate the groups. The mean and SD of TUVs for the groups were: hyperthyroid (36.5% +/- 16.5%), euthyroid (14.4% +/- 5.48%) and hypothyroid (13.7% +/- 7.5%). The unpaired T test showed statistically significant difference between hyperthyroid and euthyroid groups (p < 0.01). There was no significative difference between hypothyroid and euthyroid groups (p = 0.55). The 23% TUV has the best sensitivity (80%)/specificity (93%) ratio to separate hyperthyroid from euthyroid groups. There was not a good TUV to separate euthyroid form hypothyroid groups. In conclusion, it can be established 23% as the optimal superior limit for the normal uptake values. However, it was not possible to establish a suitable inferior limit, due to the expressive overlay of TUVs of hypothyroid and euthyroid groups.

Adolescent↗
PubMed1989

A self-consistent set of reference values for 23 clinical chemical analytes.

Heparinized plasma of 528 blood donors was subjected to the 23 most frequently ordered chemical and enzymatic tests. The central fraction of the distribution of all results for each test was estimated. Out of the 528 donors a reference population has been selected. Because of the lack of other criteria, the result for any test of a blood donor was selected as a value belonging to the reference population if the results for the other 22 analytes of this particular donor lay within their own central fraction. On this basis an iterative procedure for the selection was programmed, considering the interaction between tests. The procedure was stopped when the reference limits for all 23 tests were converging. Fractions from 0.90 to 0.98 were applied to results for men and women donors separately. The elimination procedure and the criteria to select the best fitted fraction are discussed. The derived reference intervals are designated a "self-consistent set of reference values."

Blood Chemical Analysis↗
PubMed1997

Myocardial sestamibi single-photon emission tomography: variations in reference values with gender, age and rest versus stress?

Reference data files support the evaluation of myocardial perfusion single-photon emission tomography (SPET). The aim of this study was to create a large reference data base for technetium-99m sestamibi SPET, age and gender matched to the general patient population. One hundred and twenty-eight healthy volunteers (76 males and 52 females) with a likelihood of coronary artery disease of less than 5% underwent rest and maximal exercise 99mTc-sestamibi SPET with a 2-day protocol and 180 degrees elliptical rotation. The normalized activity values of 99mTc-sestamibi in the inferior wall differed significantly between men and women. Age variations were found for men in the anterior wall. Normalized activity values in all four walls were strikingly similar during rest and stress. Our results suggest that the use of reference files in 99mTc-sestamibi SPET requires a gender- and, for males, possibly an age-matched reference population. Different reference files at rest and during stress might not be necessary.

Adult↗