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Biomedical subjects

E Leskinen

Publications and source records attributed to E Leskinen.

32 records · Page 2Linked to original sources
PubMed1984

Functional capacity of men born in 1906-10, 1926-30 and 1946-50. A basic report.

This interdisciplinary study aims at describing the functional capacity of men belonging to different generation cohorts. The development of methods for the assessment of functional capacity is also the purpose of the study. Functional capacity is defined as a hierarchy comprising physical, mental and social areas into which individuals can be placed depending on the levels of the assessed functions. The study also aims at analyzing environmental and individual factors which are assumed to cause variation in the levels of functions. The purpose of this first report is to describe the framework of the study, the methods and main results concerning differences between cohorts and occupational groups. The sampling frame consisted of the population register of Jyväskylä town in January 1981. The basic populations were men in three age groups, born in 1946-50, 1926-30 and 1906-10. From each age group a systematic random sample of 250 men was made. Persons who had moved or died by the end of August 1981 or were living in institutions (6 men) were removed from the samples. The sample sizes were further randomly reduced so that the final samples consisted of 183, 188 and 176 men. At the time of the study the ages of the cohorts were 31-35, 51-55 and 71-75. The study included postal questionnaires, interviews and laboratory examinations. The basic questionnaire dealt with the background information, living conditions, life history, occupational history, social contracts and social participation, close human relations, use of time, health status and living habits. The second postal questionnaire dealing with psychic capacity included the following main items: life changes, self-realisation, personal trait anxiety, social fears, coping, self-respect, and the purpose of life. The basic questionnaire was checked in an interview when the subjects came for the laboratory examinations. The entrance interview also included questions about the most important events of previous 24 hours. In addition the subjects filled in a questionnaire on situational anxiety. The laboratory examinations included the following tests: cognitive capacity (4 tests), audiometry, speech understanding, visual tests, vibration threshold, posture control, reaction and movement time, tapping rate, leg extension velocity, anthropometric measurements, skin measurements, bone mineral density, physiotherapist's examination, physician's examination, blood analyses, isometric strength of muscles (5 muscles), anaerobic power, aerobic power and anaerobic threshold.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1984

Assessment of analytical quality in Nordic clinical chemistry laboratories using data from contemporary national programs.

The aim of this investigation was primarily to assess analytical quality expressed as between-laboratory, within-laboratory, and total imprecision, not in order to detect laboratories with poor performance, but in the positive sense to provide data for improving critical steps in analytical methodology. The aim was also to establish the present state of the art in comparison with earlier investigations to see if improvement in analytical quality could be observed.

Blood Chemical Analysis↗
PubMed1984

External quality assessment of serum hormone determinations in the Nordic countries.

Since 1979 the Nordic Clinical Chemistry Project (NORDKEM) has organized four external quality assessment surveys of serum hormone determinations in the five Nordic countries. Charcoal-stripped control sera with weighed additions of the following hormones have been used: thyrotropin, human placental lactogen, prolactin, estriol, estradiol, testosterone, cortisol, triiodothyronine, thyroxine, and, in the fourth survey, progesterone. Human serum was usually used but in the first survey the serum matrix for the protein hormones was calf serum. In three years no systematic improvement in the coefficients of variation of the results has occurred. The change from calf serum to human serum also had no major effects on the results. Percentage coefficients of bias usually varied on both sides of the true value, but at low hormone concentrations the results were almost always positively biased. It is therefore useful to know the true hormone concentrations of the control samples because all-laboratory means are relatively often biased from these. Variation produced by different methods of calculation of the radioimmunoassay results and the influence of outlying standard points on these data processing routines were studied in the third survey. It is possible that sometimes the variation produced by different methods of calculation is one of the main components of the total variation in external quality assessment of RIA. There were no major differences between the performance of computerized or manual calculation methods. The influence of different calibration standards on serum thyroxine determination was studied in the fourth survey. Of the total coefficient of variation (10.8% to 17.0%) the component of variation produced by different thyroxine calibration standards was 0.8% to 4.6%. In conclusion, standardization of the data processing methods and further standardization of assay reagents are urgently needed to give possibilities to identify more subtle differences in the analytical performance of the laboratories. External quality assessment of hormone determinations needs improvement of the quality of reference materials.

Chemistry, Clinical↗
PubMed1984

External quality assessment of serum drug determinations in the Nordic countries.

A system for external quality assessment of serum drug determinations in the five Nordic countries has been established, and results of several surveys of antiepileptic drug determinations are described. The work was started as a pioneer work of NORDKEM at the time when NORDKEM was founded and was carried out during the years 1977-1979. The problems concerning methodology of drug analyses and, consequently, the problem of setting up quality assessment systems differ clearly from those in connection with the common analyses of clinical chemistry. Especially the quality of control materials is very important. An expert panel of drug specialists is necessary to plan and interpret an external quality assessment program of drug analyses, but it can very well be carried out in connection with other quality assessment programs. The state of the art of antiepileptic drug determinations in the Nordic countries at the time of the surveys was very good. The level of inaccuracy was well below 5%, and the level of imprecision was mainly in the range of 15-20%, although no outliers were excluded during the statistical treatment of the data.

Anticonvulsants↗
PubMed1984

Internal quality control of hormone determinations by RIA. Detection of clinically significant analytical errors of serum thyroxine determination.

An internal quality control system by which clinically significant analytical errors can be detected with high probability was developed for serum thyroxine (T4) determination by RIA. The mean concentration of the quality control samples (C1, C2, and C3) were 40.0, 101.8, and 156.7 nmol/l, and their total standard deviations (st) 2.5, 4.1, and 7.1 nmol/l, respectively, in stable analytical performance of the T4 assay. From the clinical point of view it was accepted that the results of C1 varied from 30 to 50 nmol/l at the most. When expressed in standard deviations, the same size of error was accepted for C2 and C3. It followed that the quality control system had to detect a systematic shift of 2.43st (delta SEc) and a 2.08 times increase in random error (delta REc) in order that the quality goals could be reached. With three control samples the combination of rules, 1: 3s/CS1: (1.0s; 2.7s), which was chosen for manual quality control, detected the delta SEc with about an 80% probability and the delta REc with about a 30% probability. The probability of false rejections was less than 1%. The probability of detecting the delta SEc was considered acceptable, but to detect the delta REc with a higher probability, the within-assay variation of each run was calculated from the results of duplicate patient samples. Although the whole run was not rejected because of systematic and/or random errors, individual samples were reanalysed if the results of their duplicate determinations differed from the criteria stated.(ABSTRACT TRUNCATED AT 250 WORDS)

False Negative Reactions↗
PubMed1980

Present analytical quality in the Nordic clinical chemistry laboratories.

An introductory review is given of the discussion in the Nordic countries on the definition, aim, and optimal organization of quality control. Published and unpublished Scandinavian works have been reviewed and commented under the following headlines: common chemical analyses, enzyme analyses, serum and plasma protein analyses, hormone analyses, drug analyses, hematological tests, and urine analyses. It is concluded that methods for calculating medical standards of analytical quality in clinical chemistry form the logical background for the design of an optimal quality control system, which will guarantee that analytical results well have a specified probability of satisfying the medical requirements.

Chemistry Techniques, Analytical↗