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H E Solberg

Publications and source records attributed to H E Solberg.

At least 19 recordsLinked to original sources
PubMed1999

Open laboratory information systems: a case study.

The EU-AIM project "OpenLabs" specified an open systems architecture for a clinical laboratory information system (LIS) environment and coined the term "open LIS". Since this conception has not yet been realized into systems and modules commercially available, two university hospitals in Norway had to specify an alternative model for openness when they, in a joint project, screened the market for a new LIS. To be open, a LIS must be (1) based on main-trend hardware and system software running under a standardized operating system, (2) designed for network-based distributed computing, (3) have sufficient documentation available to local staff, (4) be configurable through parameters, tables and scripts, and (5) have general and configurable access mechanisms both to real-time processes and to the database. The present study describes the selection process and examines the compliance of the selected LIS (NetLab) with this model of openness. It is shown that local staff have been able to adapt this LIS to various and changing requirements in the laboratory.

Information Systems↗
PubMed1997

[Sedimentation rate and renal cancer].

This paper is based on two articles published in 1996 in Journal of Internal Medicine. One is an evaluation of the erythrocyte sedimentation rate (ESR) measured in 3910 subjectively healthy Norwegians of both sexes, with an age range of 20 to 90 years. The authors underline the difference between a population-based and a subject-based upper ESR reference level, and the benefit of knowing each single healthy person's subject-based ESR level. The other article shows that, in 70% of a sample of 236 randomly selected patients with renal cell carcinoma, a diagnosis could have been indicated several years before clinical symptoms or signs became apparent. Therefore, the ESR might be a predictive test for many such cancer cases. This type of cancer has a good prognosis when treated surgically at an early stage. In Norway, 432 new cases occurred in 1993, 264 in men and 168 in women. If our observations are generally applicable, and proper attention had been paid to a slowly increasing ESR value over time, about 300 of these cases could have been operated on much earlier. It is suggested that physicians and public might both benefit from this knowledge.

Adult↗
PubMed1996

The CCL conferences revisited.

The history of the ten conferences on Computing in Clinical Laboratories (CCL) since the first one in Birmingham, UK, 1975, mirrors the developments in medical laboratory computing during nearly twenty years.

Clinical Laboratory Information Systems↗
PubMed1996

Rising erythrocyte sedimentation rate during several years before diagnosis can be a predictive factor in 70% of renal cell carcinoma patients. The benefit of knowing subject-based reference values.

OBJECTIVES: A diagnosis of renal cell carcinoma (RCC) early enough for potentially curative surgery is difficult. We wanted to establish whether the erythrocyte sedimentation rate (ESR) in RCC patients had begun to rise before the appearance of any symptoms or signs and, if so, when. DESIGN: A retrospective study of the evolution of the ESR in 236 randomly selected RCC patients during several years before diagnosis, comparing the results with previously obtained population-based control values. RESULTS: It is generally held that RCC patients have a high ESR at diagnosis. In our material, however, 29.7% of the RCC cases had an ESR that at this time was at or below the population-based upper reference limit; it had not increased significantly, neither with time before diagnosis, nor with age. In 70.3% of RCC patients the ESR was increased and had been significantly rising for up to 6 years or more before diagnosis. This had not been adequately responded to, probably because the physicians lacked knowledge of the patients' baseline ESR, and because none of the prediagnostic readings had been above the population-based reference limit. CONCLUSIONS: Systematic ESR graphic recordings over time will enable a physician to determine each individual's baseline value, and hence note any continuously rising trend, which should lead to further investigations, e.g. an ultrasound kidney examination. This may provide an early clue to many otherwise non-symptomatic RCC cases. It is time for a reappraisal of the predictive value of the ESR to discover early RCC, and possibly other diseases as well.

Adult↗
PubMed1996

Population-based erythrocyte sedimentation rates in 3910 subjectively healthy Norwegian adults. A statistical study based on men and women from the Oslo area.

OBJECTIVES: To establish age- and sex-specific reference limits for the erythrocyte sedimentation rate (ESR) in asymptomatic Norwegian adults. DESIGN: Single ESR recordings were obtained by the classical or a modified Westergren method from 2145 men and 1765 women (93% being blood donors) with age range 20-90 years, and analysed statistically. RESULTS: There was a significant positive association between ESR level and age, consistent with a parabolic pattern in men but a linear one in women. The mean values for men were about 3 mm h-1 at 20 years, 6 mm h-1 at 55 years, and 10 mm h-1 at 90 years, and 6, 9, and 11 mm h-1 respectively for women. These averages (predicted by regression lines) were significantly higher in women up to the age of 75 years, after which the estimated sex-specific 95% confidence limits for mean values were found to overlap. CONCLUSIONS: The upper reference levels expected to be exceeded only by chance in 5% of single individual recordings at the ages of 20, 55 or 90 years, respectively, were estimated to be 12, 14 and 19 mm h-1 for men, and 18, 21 and 23 mm h-1 for women. Higher values should be controlled and, if confirmed, lead to a clinical check-up. However, about 76% of our overall material had ESR values lower than 9 mm h-1. Knowledge of each person's baseline ESR value might increase the disease-predictive ability of the test. If several measurements over years reveal a steeper rise with age than depicted in our population-based curves, it should be taken seriously, even when each reading is below the population-based reference limits.

Adult↗
PubMed1995

RefVal: a program implementing the recommendations of the International Federation of Clinical Chemistry on the statistical treatment of reference values.

RefVal is a computer program that implements the recommendations of the International Federation of Clinical Chemistry on the statistical treatment of reference values. The program performs the following main tasks: graphical display of the distribution of reference values, identification or elimination of outliers, testing of the fit of the distribution to Gaussian shape (coefficients of skewness and kurtosis, Anderson-Darling's test, Cramér-von Mises' test, Kolmogorov-Smirnov's test), non-parametric and parametric estimation of reference limits (fractiles, percentiles). The parametric estimation method is based on a two-stage mathematical transformation of data: (1) Manly's exponential transformation (to remove skewness) and (2) John and Draper's modulus transformation (to adjust for remaining kurtosis). The program exists in different versions. The paper describes two of these: (1) a library of FORTRAN functions and subroutines and (2) a Pascal PC program that runs under MS-DOS.

Bias↗
PubMed1995

Multivariate reference regions.

A high frequency of "false positive" conclusions is often the outcome when several laboratory test results are interpreted by comparing each single test result with the corresponding reference interval, i.e., by multiple univariate comparisons. The adequate solution to this problem is the application of a multivariate reference region for the test profile. This region is a straightforward extension of the univariate reference interval to the multidimensional situation.

Clinical Laboratory Techniques↗
PubMed1995

Subject-based reference values.

Medical decisions based on comparison with group-based reference value have often less than desired sensitivity to significant changes in the biochemical or physiological state of an individual under investigation. Subgrouping of the reference values according to sex, age, or other criteria does frequently not solve this problem. The better solution is to compare new values with old results from the same individual, i.e., with subject-based reference values. Two types of criteria may be used: those based on critical differences between two results (the reference change limit) and those based on time-series models.

Clinical Laboratory Techniques↗
PubMed1993

Object-oriented methods.

In modern computer science and practice, there is a strong trend towards object-oriented methods, a tendency that has a bearing also on clinical laboratory computing. The purpose of this introduction is to present the concepts of objects and object-oriented methods from a laboratory scientist's point of view.

Clinical Laboratory Information Systems↗
PubMed1993

A guide to IFCC recommendations on reference values.

Six recommendations on the theory, production, and use of reference values have been prepared by the IFCC's Expert Panel on Theory of Reference Values. This review serves as a guide to the documents and presents the main topics.

Chemistry, Clinical↗
PubMed1993

Artificial neural networks in diagnosis of thyroid function from in vitro laboratory tests.

We studied the potential benefit of using artificial neural networks (ANNs) for the diagnosis of thyroid function. We examined two types of ANN architecture and assessed their robustness in the face of diagnostic noise. The thyroid function data we used had previously been studied by multivariate statistical methods and a variety of pattern-recognition techniques. The total data set comprised 392 cases that had been classified according to both thyroid function and 19 clinical categories. All cases had a complete set of results of six laboratory tests (total thyroxine, free thyroxine, triiodothyronine, triiodothyronine uptake test, thyrotropin, and thyroxine-binding globulin). This data set was divided into subsets used for training the networks and for testing their performance; the test subsets contained various proportions of cases with diagnostic noise to mimic real-life diagnostic situations. The networks studied were a multilayer perceptron trained by back-propagation, and a learning vector quantization network. The training data subsets were selected according to two strategies: either training data based on cases with extreme values for the laboratory tests with randomly selected nonextreme cases added, or training cases from very pure functional groups. Both network architectures were efficient irrespective of the type of training data. The correct allocation of cases in test data subsets was 96.4-99.7% when extreme values were used for training and 92.7-98.8% when only pure cases were used.

Humans↗
PubMed1993

Establishing reference values from adults: recommendation on procedures for the preparation of individuals, collection of blood, and handling and storage of specimens. Committee on Reference Values of the Scandinavian Society for Clinical Chemistry.

The concentrations of blood components are influenced by a number of preanalytical factors, the importance of which varies [1]. Therefore it is necessary to standardize the specimen collection, as was done by the Committee on Reference Values of the Scandinavian Society for Clinical Chemistry and Clinical Physiology, which in 1975 published its recommendation on the production of reference values in clinical chemistry [2]. It was the very first recommendation of its kind. Since then, new information has accumulated, and it has become necessary to revise the part concerning the preparation of subjects for blood collection, the collection procedure itself, and the subsequent handling of the specimen. Also, The International Federation of Clinical Chemistry (Expert Panel on Theory of Reference Values) has produced its own recommendation [3]. The recommendation described below replaces pp. 39-44 of the former Scandinavian recommendation [2]. The procedure described below is designed for the collection of specimens for the measurement of the majority of components in blood and specimen collection from the cubital vein is described. It can be easily adapted for the collection of blood from other vessels [4]. Certain laboratory investigations require a special protocol. In that case, the preparation of the subject prior to and during specimen collection as well as the procedure itself should be described in sufficient detail to permit reproduction by adequately trained personnel. In any project designed to produce reference values the same protocol for the preparation of individuals and specimen collection should be used throughout the project. The protocol should be described in detail. Thus, it is not satisfactory to state only that the present recommendation was followed. Each section of the recommendation is followed by a check list for points which should be taken into account.

Adult↗
PubMed1991

The selection of laboratory tests for organ dysfunctions using multivariate statistics.

There is a need for selecting good combinations of laboratory tests for various medical decision situations. Multivariate statistical methods are better tools for this type of selection than multiple univariate comparisons of candidate tests. Linear discriminant analysis is a suitable method. The best selection strategies are stepwise selection and evaluation of all possible subsets. Guiding criteria in the selection process may be measures of statistical separation between the clinical groups or empirical probabilities of correct reallocation. The latter criterion has the advantage that an optimum subset size may be identified.

Clinical Laboratory Techniques↗