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 37 records · Page 2Linked to original sources
PubMed1990

Reference values, why and how.

A review describing the fallacies of the concept of normal values and the reasons for its substitution with reference values. The "reference value philosophy", its terminology and recommended practical procedures are presented and it is warned not to use incorrect terms such as "normal reference range". The concepts of health and disease are discussed from the point of view of the laboratory. Reference values are not always derived from "healthy" persons. In order to be comparable, reference values and observed (i.e. patient) values should be produced in the same way, using the same analytical procedure, quality control, etc. The influence of preanalytical factors such as food intake, posture, use of tourniquet and freezing and storing samples is great and necessitates standardisation of specimen collection. Strategies for the selection of reference individuals are presented and the reasons and methods for subdivision of the data are described. Descriptions are also given of the individual reference values and the statistical treatment of collected data including multivariate analysis. Finally, the reporting of observed values in relation to reference values is discussed. There is a trend to avoid the use of the reference interval because of the temptation to regard the values falling outside it as pathological.

Data Collection↗
PubMed1992

[Factors that influence reference values].

The factors that influence reference values are briefly reviewed using our experimental data. The factors can be divided into the following 3 subfactors: analytical technology, selection of so called healthy person and statistical method. The most large effect came from a variety of physiological conditions in healthy persons, i.e., age, sex, diurnal and menstrual rhythms, drinking and smoking habits, diet, physical exercise, posture, tourniquet etc. A new concept of tow-step reference values "the basal value and the equivocal value" is postulated from the studies of the effect of these physiological conditions. The effects of the statistical methods for obtaining the distribution type of data of normal reference group and the 95% reference range were not so large. Then, we conclude that the reference values or the reference ranges should be made in your own laboratories using carefully selected healthy persons even if 30 or 50 small numbers are used.

Adolescent↗
PubMed1989

Haematological and biochemical reference values for the koala (Phascolarctos cinereus).

Haematological and biochemical reference values were established from 45 clinically healthy koalas. Statistical analysis revealed no significant differences for sex and season of sampling. Immature koalas had significantly higher alkaline phosphatase and inorganic phosphate values, and significantly lower total protein concentrations due to low globulins values. Enzyme reference values tended to be wide and could limit their usefulness in detecting disease. In the reference values for leukocytes, neutrophils and lymphocytes, the inclusion of low values which were not actually seen may interfere with the detection of reduced levels due to disease.

Animals↗
PubMed1990

Biochemical reference values in elderly black subjects.

Biochemical reference values for the black age group of greater than or equal to 65 years were determined from the black urban population of the Orange Free State. Biochemical investigations performed were those included in the Sequential Multiple Analyser Computer profile because it includes the 20 most requested clinical chemistry investigations. Most of the reference values corresponded to values for the same age groups in the Western world. There was no age-related rise in the alkaline phosphatase values, which suggested absence of occult Paget's disease. Reference values for serum total protein and globulin were found to be higher than values derived from elderly white groups.

Age Factors↗
PubMed1989

[Reference values of ambulatory arterial pressure in activity and during the night. Multicenter study of 394 normotensive subjects at rest].

The blood pressure pattern and variability were assessed in a population of 394 normotensive subjects (OMS) stratified by age (20 to 75 years) and sex. Ambulatory blood pressure measurements were performed with an automatic device (Spacelabs 5200) every 15 min. from 6 a.m. to 12 p.m., and every 30 min. from 0 a.m. to 6 a.m. The analysis was effected during normal daily activities (from 9 a.m. to 7 p.m.) and during night (from 11 p.m. to 7 a.m.). Blood pressure levels were higher in males than females. During daytime and nighttime, diastolic blood pressure rose with age until 59 years while SBP was not affected, except for the females older than 60 years. After this age, diastolic blood pressure decreased. No epidemiological study has provided a measure of the cardiovascular risk related to ambulatory blood pressure, so that we were unable to define true normal values. However, reference population values provided from two statistical methods: limit of the 95th upper confidence interval for the mean of limit of the 90th percentile value for the total data. These blood pressure distributions according to age and sex may allow a better approach to borderline hypertensive patients.

Adult↗
PubMed1987

Neonatal reference values for ionized calcium, phosphate and magnesium. Selection of reference population by optimality criteria.

Thirty-one full-term newborn babies were investigated in order to establish reference values for ionized calcium. Only children fulfilling certain optimality criteria (with best possible maternal and infant conditions and uncomplicated pregnancy and delivery) were included. All infants were breast fed. Capillary blood for analysis of ionized calcium was collected by heel puncture on day 1 (6-36 h post partum, p.p.), day 3 (60-84 h p.p.) and day 5 (108-132 h p.p.). Ionized calcium was measured with a semi-automatic electrode system ICA 1 (Radiometer A/S, Copenhagen, Denmark). The reference ranges (mean +/- 2 SD) for days 1, 3 and 5 were 1.05-1.37, 1.10-1.42 and 1.20-1.48 mmol/l, respectively. The mean ionized calcium concentration on day 1 was significantly lower than on days 3 and 5. Reference values are also given for total calcium, magnesium and phosphate. We emphasize that it is impossible to calculate ionized calcium from total calcium or vice versa.

Calcium↗
PubMed1979

Peak expiratory flow rate. Reference values for Swedish children.

Reference values for the peak expiratory flow rate assessed by the Wright-McKerrow peak flow meter have been established for Swedish children. The material consisted of 143 boys and 132 girls. We recommend the sexes be considered together. The equation of the regression line is 72.14 x height3 + 96.12. The coefficient of correlation is 0.93 and the residual standard deviation 13.7%.

Body Height↗
PubMed1988

Cerebrospinal fluid IgG in childhood: the establishment of reference values.

A retrospective analysis of quantitative and qualitative immunoglobulin G (IgG) results from 253 children who were either medically and neurologically normal or highly unlikely to have abnormalities of CSF IgG is reported. Normal values in this reference population vary with age for CSF/albumin IgG ratio and CSF/serum IgG index and are significantly different from the adult reference values. The rate of false positivity is lower for quantitative values than for qualitative IgG determinations (oligoclonal bands).

Adolescent↗
PubMed1975

[Reference values in biology. Use and special value in preventive medicine].

The idea of reference values should replace in biology, the idea of normal or abnormal values. In fact, progress in physiopathology and laboratory techniques has demonstrated the difficulty of fine interpretation of laboratory examinations. It is first necessary to understand factors of variation due to sampling, then the techniques of analysis themselves. Then, the importance of variations within and between individuals for each laboratory examination. Among the most important factors, we may quote age, sex, drugs, exercise, etc. These various possibilities of interference may be classified in order to remember only those which may falsify reference values, i.e. the values used for clinical interpretation. Thus, these factors are of greater importance in preventive medicine where finer and earlier variations may be observed. The best reference is that of the individual himself, if laboratory examinations are to be used profitably both in preventive and curative medicine. It would be necessary to draw up, for each subject, reference values during a period of good health between the ages of 18 and 25.

Adult↗