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At least 19 recordsLinked to original sources
PubMed1975

Current concepts of "normal values," "reference values," and "discrimination values," in clinical chemistry.

The term "normal values" is seriously afflicted by sylleptic ambiguities and conceptual problems, and it is gradually being discarded from the lexicon of clinical chemistry. The neutral term "reference values" preferable on semantic and scientific grounds, and its use in clinical chemistry is rapidly gaining acceptance. The term "discrimination value" has been added to the lexicon of clinical chemistry. Use of the "discrimination value" for the results of a laboratory test in a specified clinical situation provides the optimal discrimination between the "healthy" and the "diseased," or between "those who need not be investigated further" and "those who do."

Biometry↗
PubMed1990

Recommendation for collection of venous blood from children, with special reference to production reference values.

Reference values should be produced under standardized conditions. To enable comparison it is desirable to use the same procedure also in other clinical situations. A procedure for the collection of venous blood from children with special reference to production of reference values is recommended. It deals with five items: preparation of the child before specimen collection, preparation of the blood collection site, equipment for specimen collection, the specimen collection itself, and handling and storage of the specimen. Alternative methods are described since no single method is suitable for all paediatric age groups. The problem of adhering to a proposed procedure during routine clinical work is also commented upon. The recommendation has been produced as a joint effort of the Scandinavian Committee on Reference Values and a working group set up by the National Paediatric Societies in the Nordic countries.

Adolescent↗
PubMed1987

[Amino acids in cerebrospinal fluid. Reference values].

Reference values are determined for 28 amino-acids in the cerebro spinal fluid, from literature data. The data collected in this document result from the dosage of amino-acids in the cerebro spinal fluid of 453 patients, adults and children. Two series of reference values are proposed: one for children over 2 and adults, the other for children under 2.

Adolescent↗
PubMed1988

Trace elements in human clinical specimens: evaluation of literature data to identify reference values.

Reference values are proposed for the concentrations of As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Pb, Se, and Zn in whole blood, blood serum, urine, milk, liver, and hair from adult human subjects. For F, I, and Ni, it was not possible to evaluate reference intervals for all the specimens mentioned above. For several elements, including Al, B, Br, Cs, Li, Rb, U, and V, the present status of the literature does not provide an adequate basis for formulating baseline concentrations; therefore, results from selected investigations are listed for information only. For elements such as Cu, Fe, and Zn, which are known to be homeostatically controlled, the concentrations in whole blood and blood serum follow a gaussian-like frequency distribution, and we could consider both median and mean values for evaluation. On the other hand, elements whose concentrations in tissues and body fluids are influenced by dietary availability (e.g., As and Se) or environmental factors (e.g., Cd, Hg, and Pb) show wide scatter. In these cases, the median appeared to be a better indicator of the central tendency than the mean, when different populations are involved. These points are illustrated.

Body Fluids↗
PubMed1979

Canine hematology and biochemistry reference values.

Reference hematology and biochemistry values for 53 variables are presented from 51 clinically healthy dogs, 26 female and 25 male, approximately six to 24 months of age and of mixed breed. These dogs were sampled because of their good health status and the opportunity to collect the volume of blood required to complete the variable analysis of interest. Collection of blood specimens and laboratory analysis was done in a standard described manner, the latter including a continuing quality control program. For each variable the data were examined for homogeneity and when present, outliers (n = 9) were excluded. Parametric analysis was used to calculate the reference interval for those variables which had a Gaussian distribution or could be changed to a Gaussian distribution by any of four transformations. For those variables in which Gaussian distribution was not present or attained, nonparametric analysis was used. Due to the small size of the population sample, the uncertainty of breed and the exact age of each dog, breed, age and sex effects were not examined. Reference values should be used to assist interpretation of observations obtained from an animal or animals of comparable origin, i.e. similar subpopulation, and only if the same laboratory techniques are followed. Until each laboratory is able to generate reference values using adequate sample size and current methodology for the numerous subpopulations of interest, reference intervals such as these are useful to clinicians and researchers.

Animals↗
PubMed1986

Clinical biochemical values of llamas: reference values.

Fifteen clinical biochemical measurements were done on serum from 64 clinically healthy adult llamas (26 males and 38 females). Values for several of these tests were different from those reported for llamas and from reference values for other domesticated ruminants. Comparison of values between males and females revealed significant differences for several tests. Clinical biochemical values reported in the present study can serve as reference values for adult llamas.

Animals↗
PubMed1987

Recommendation for collection of skin puncture blood from children, with special reference to production of reference values.

Reliable reference values need to be collected under standardized conditions. In order to enable comparison of values observed on patients with reference values, it is also desirable to use the same standardized conditions on patients. The present recommendation was produced as a joint effort of representatives of the clinical chemists and paediatricians of Scandinavia and describes the following details. Preparation of the child before specimen collection (food intake, time of day, physical activity, posture, environment), preparation of skin puncture site (warming, disinfection, ointment), instruments for blood collection (lancet, blood collection vessel), site of puncture (plantar surface of foot, finger, ear lobe), collection of emerging blood and handling and storage of the specimen.

Adolescent↗
PubMed1978

[Reference values of respiratory parameters in adults 4th paper: reference values for screening parameters of lung mechanics (author's transl)].

Reference values for screening parameters, evaluating the shape of flow-volume-curves on forced expiration, were calculated from measurements in 1127 healthy subjects aged between 13 and 72 years. The following parameters were determined by means of the electronic spirometer pneumo-test: 1. the peak flow value Vmax, 2. the whole time constant tauges of the flow volume diagram and its components tau1 and tau2 from the upper and the lower part of the flow volume curve, 3. the most frequent time constant taumax in the distribution function of time constants. In relation to age Vmax-values show a maximum at 35 years and a significant decrease in younger and older subjects. Values in women are significant smaller than in men throughout the range of age. The time constants tauges and tau1 decrease significantly with increase in age. Differences between females and males are not statistically significant for these parameters. The time constants tau2 and taumax are age-independent. Their mean values are identical in all age decades and in women significantly smaller than in man.

Adolescent↗
PubMed1990

[Clinical reference values for laboratory hematology tests calculated using the iterative truncation method with correction: Part 1. Reference values for erythrocyte count, hemoglobin quantity, hematocrit and other erythrocyte parameters including MCV, MCH, MCHC and RDW].

Age and sex dependent differences in the clinical reference values for erythrocyte count (RBC), hemoglobin quantity (Hb), hematocrit (Ht) and other erythrocyte parameters including MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin), MCHC (mean corpuscular hemoglobin concentration) and RDW (red cell distribution width), were calculated by the iterative truncation method with correction (Usui's method) using the results from tests on 6,300 patients' specimens obtained at Kyoto University Hospital. For RBC, Hb and Ht, the data obtained from the individuals below 13 years old showed the normal or sometimes log-normal distribution, but adjustment by the Xn-type variable transformation was often necessary to obtain the normal distribution for the data taken from the populations containing individuals over the age of 14. For the clinical reference values of RBC, Hb and Ht, no sex difference was observed below the age of 12. The values for males were significantly higher than those of females in the age range 13-79, and the values showed no significant sex-dependent difference at ages above 80. In females, age-dependent change of values for RBC, Hb and Ht was less prominent than in males; especially the upper limit values for females were very stable for all ages. MCV and MCH gradually increased with age both in males and females, and the MCHC remained constant in all age populations of male and female. The reference value for RDW was generated by the percentile method instead of the iterative truncation method because of the strong deviation in the distribution pattern, and the RDW values showed a gradual increase with age in both males and females.

Age Factors↗
PubMed1989

Doppler ultrasonography of the fetoplacental circulation--normal reference values.

Normal reference values for the resistance index, A/B ratio and pulsatility index of the umbilical artery obtained by Doppler ultrasonography are presented. The resistance index and A/B ratio values are very similar to those previously published, indicating no need to formulate normal values for different populations. The pulsatility index differed from other published values, probably reflecting different calculation methods built into the spectrum analysers rather than differences in waveforms. The resistance index had the lowest coefficient of variation and showed least inter-observer variation. For routine use the resistance index is preferable to other indices.

Adult↗