Biomedical subjects

Pål Rustad

Publications and source records attributed to Pål Rustad.

4 recordsLinked to original sources

PubMed2004

[Updated reference intervals for clinical chemical components].

BACKGROUND: More or less outdated reference intervals are still in common use with many clinical biochemical components. In order to update them, a Nordic cooperative project (the Nordic reference interval project, NORIP) was organised. MATERIAL AND METHODS: 102 Nordic laboratories participated; 3036 persons aged 18 years or above were included. 25 components were measured in serum and/or plasma. RESULTS: Common reference intervals for all Nordic countries were calculated for each of the 25 components, with age and sex-specific intervals when statistical criteria suggested this to be appropriate. INTERPRETATION: The national clinical biochemical societies of Norway, Sweden, Finland and Denmark have all recommended that the suggested reference intervals should be brought into common use. In Norway, new reference intervals for seven enzymes were implemented in May 2003, the remaining are recommended implemented in spring 2004. Except for four of the enzymes, there will be no simultaneous change in the measuring methods used, hence medical decision limits are essentially not affected.

Adolescent↗

PubMed2004

Partitioning of nongaussian-distributed biochemical reference data into subgroups.

BACKGROUND: The aim of this study was to develop new methods for partitioning biochemical reference data, covering in particular nongaussian distributions. METHODS: We recently proposed partitioning criteria for gaussian distributions. These criteria relate to proportions of the subgroups outside each of the reference limits of the combined distribution (proportion criteria) and to distances between the subgroup distributions as correlates of these proportions (distance criteria). However, distance criteria do not seem to be ideal for nongaussian distributions because a generally valid relationship between proportions and distances cannot be established for these. RESULTS: Proportion criteria appear preferable to distance criteria for two additional reasons: (a) The prevalences of the subgroup populations may have a considerable effect on stratification, but these are hard to account for by using distance criteria. Two methods to handle prevalences are described, the root method and the multiplication method. (b) Tied reference values, another complication of the partitioning problem, could also be hard to take care of using distance criteria. Some solutions to the problems caused by tied reference values are suggested. CONCLUSIONS: Partitioning of biochemical reference data should preferably be based on proportion criteria; this is particularly true for nongaussian distributions. Both of the described complications of the partitioning problem, the prevalences of the subgroups and tied reference values, are hard to deal with using distance criteria, but the proposed methods make it possible to account for them when proportion criteria are applied.

Clinical Laboratory Techniques↗

PubMed2004

[New common reference intervals for clinical chemistry in the Nordic countries. A better basis for clinical assessment and cooperation].

A project engaging the five Nordic countries has presented common reference intervals for the most frequently used biochemical and haematological analytes. The results are based on samples from up to 3000 healthy adult reference persons and are statistically calculated to include 95% of the reference population's values. Reference samples were analyzed together with commutable control materials traceable to reference methods (IMEP-17). Enzymes were analyzed using methods traceable to IFCC reference methods. The Swedish Society of Clinical Chemistry now recommends its member laboratories to introduce the new reference intervals and new enzyme methods during 2004.

Adult↗

PubMed2004

Proposal for guidelines to establish common biological reference intervals in large geographical areas for biochemical quantities measured frequently in serum and plasma.

A suggestion for a standard procedure to establish biological reference intervals for biochemical quantities by a multicenter approach is presented. This procedure was developed for and used in the Nordic Reference Interval Project 2000 (NORIP). This project established biological reference intervals for 25 frequently requested biochemical quantities through cooperation of 102 Nordic laboratories. Each laboratory performed collection of reference samples and measurement using their routine methods. The bias of each routine method was eliminated by use of common reference materials measured in each of the participating laboratories.

Blood Chemical Analysis↗