Publications by authors named "Kristin Moberg Aakre"

21 Publications

  • Page 1 of 1

Biological variation, reference change values and index of individuality of GDF-15.

Clin Chem Lab Med 2021 Oct 14. Epub 2021 Oct 14.

Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1515/cclm-2021-0769DOI Listing
October 2021

Determinants of Interindividual Variation in Exercise-Induced Cardiac Troponin I Levels.

J Am Heart Assoc 2021 09 28;10(17):e021710. Epub 2021 Aug 28.

Cardiology Department Stavanger University Hospital Stavanger Norway.

Background Postexercise cardiac troponin levels show considerable interindividual variations. This study aimed to identify the major determinants of this postexercise variation in cardiac troponin I (cTnI) following 3 episodes of prolonged high-intensity endurance exercise. Methods and Results Study subjects were recruited among prior participants in a study of recreational cyclists completing a 91-km mountain bike race in either 2013 or 2014 (first race). In 2018, study participants completed a cardiopulmonary exercise test 2 to 3 weeks before renewed participation in the same race (second race). Blood was sampled before and at 3 and 24 hours following all exercises. Blood samples were analyzed using the same Abbot high-sensitivity cTnI STAT assay. Fifty-nine individuals (aged 50±9 years, 13 women) without cardiovascular disease were included. Troponin values were lowest before, highest at 3 hours, and declining at 24 hours. The largest cTnI difference was at 3 hours following exercise between the most (first race) (cTnI: 200 [87-300] ng/L) and the least strenuous exercise (cardiopulmonary exercise test) (cTnI: 12 [7-23] ng/L; <0.001). The strongest correlation between troponin values at corresponding times was before exercise (=0.92, <0.0001). The strongest correlations at 3 hours were between the 2 races (=0.72, <0.001) and at 24 hours between the cardiopulmonary exercise test and the second race (=0.83, <0.001). Participants with the highest or lowest cTnI levels showed no differences in race performance or baseline echocardiographic parameters. Conclusions The variation in exercise-induced cTnI elevation is largely determined by a unique individual cTnI response that is dependent on the duration of high-intensity exercise and the timing of cTnI sampling. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02166216.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/JAHA.121.021710DOI Listing
September 2021

Biomarker Testing Considerations in the Evaluation and Management of Patients With Heart Failure: Perspectives From the International Federation of Clinical Chemistry and Laboratory Medicine Committee.

J Card Fail 2021 Jul 10. Epub 2021 Jul 10.

Department of Laboratory Medicine and Pathology, Hennepin Healthcare/HCMC, Minneapolis, Minnesota; USA and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cardfail.2021.06.018DOI Listing
July 2021

Quality benchmarking of smartphone laboratory medicine applications: comparison of laboratory medicine specialists' and non-laboratory medicine professionals' evaluation.

Clin Chem Lab Med 2021 03 23;59(4):693-699. Epub 2020 Nov 23.

University of Ljubljana, Faculty of Pharmacy, Ljubljana, Slovenia.

Objectives: There are many mobile health applications (apps) now available and some that use in some way laboratory medicine data. Among them, patient-oriented are of the lowest content quality. The aim of this study was to compare the opinions of non-laboratory medicine professionals (NLMP) with those of laboratory medicine specialists (LMS) and define the benchmarks for quality assessment of laboratory medicine apps.

Methods: Twenty-five volunteers from six European countries evaluated 16 selected patient-oriented apps. Participants were 20-60 years old, 44% were females, with different educational degrees, and no professional involvement in laboratory medicine. Each participant completed a questionnaire based on the Mobile Application Rating Scale (MARS) and the System Usability Scale, as previously used for rating the app quality by LMS. The responses from the two groups were compared using the Mann-Whitney U test and Spearman correlation.

Results: The median total score of NLMP app evaluation was 2.73 out of 5 (IQR 0.95) compared to 3.78 (IQR 1.05) by the LMS. All scores were statistically significantly lower in the NLMP group (p<0.05), except for the item Information quality (p=0.1631). The suggested benchmarks for a useful appear: increasing awareness of the importance and delivering an understanding of persons' own laboratory test results; understandable terminology; easy to use; appropriate graphic design, and trustworthy information.

Conclusions: NLMP' evaluation confirmed the low utility of currently available laboratory medicine apps. A reliable app should contain trustworthy and understandable information. The appearance of an app should be fit for purpose and easy to use.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1515/cclm-2020-0869DOI Listing
March 2021

High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014.

J Am Heart Assoc 2020 10 15;9(19):e017363. Epub 2020 Sep 15.

Cardiology Department Stavanger University Hospital Stavanger Norway.

Background Use of snus, a smokeless tobacco product, is increasing in Scandinavia. Strenuous physical activity is associated with an acute increase in high-sensitivity cardiac troponin (swhs-cTn) concentrations. Current smoking is associated with lower hs-cTn, but whether this also holds true for smokeless tobacco and whether tobacco affects the hs-cTn response to exercise remain unknown. Methods and Results We measured hs-cTnI and hs-cTnT concentrations in 914 recreational athletes before and 3 and 24 hours after a 91-km bicycle race. Self-reported snus tobacco habits were reported as noncurrent (n=796) and current (n=118). The association between snus use and change in log-transformed hs-cTnI and hs-cTnT concentrations (ie, the differences between concentrations at baseline and 3 hours and 24 hours ) were assessed by multivariable linear regression analysis. Concentrations of hs-cTn at baseline were lower in current than in noncurrent snus users (hs-cTnI median, 1.7 ng/L; Q1 to Q3: 1.6-2.3 versus 2.0 ng/L; Q1 to Q3: 1.6-3.2 [=0.020]; and hs-cTnT: median, 2.9 ng/L, Q1 to Q3: 2.9-3.5 versus 2.9 ng/L, Q1 to Q3: 2.9-4.3 [=0.021]). In fully adjusted multivariable models, use of snus was associated with lower change in hs-cTn concentrations from baseline to 3 hours (hs-cTnI: -29% [=0.002], hs-cTnT: -18% [=0.010]) and 24 hours (hscTnI: -30% [=0.010], hs-cTnT -19%, [=0.013]). Conclusions Resting hs-cTn concentrations are lower and the exercise-induced cardiac troponin response is attenuated in current users of smokeless tobacco compared with nonusers. Further insight into the pathophysiological processes underlying the attenuated cardiac troponin response to exercise in tobacco users is needed. Registration URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT02166216.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/JAHA.120.017363DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7792397PMC
October 2020

Systemic Cardiac Troponin T Associated With Incident Atrial Fibrillation Among Patients With Suspected Stable Angina Pectoris.

Am J Cardiol 2020 07 12;127:30-35. Epub 2020 Apr 12.

Department of Heart Disease, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science, University of Bergen, Bergen, Norway.

Higher concentrations of cardiac troponin T are associated with coronary artery disease (CAD) and adverse cardiovascular prognosis. The relation with incident atrial fibrillation (AF) is less explored. We studied this association among 3,568 patients evaluated with coronary angiography for stable angina pectoris without previous history of AF. The prospective association between high-sensitivity cardiac troponin T (hs-cTnT) categories (≤3 ng/L; n = 1,694, 4-9; n = 1,085, 10 to 19; n = 614 and 20 to 30; n = 175) and incident AF and interactions with the extent of CAD were studied by Kaplan-Meier plots and Cox regression. Risk prediction improvements were assessed by receiver operating characteristic area under the curve (ROC-AUC) analyses. During median (25 to 75 percentile) 7.3 (6.3 to 8.6) years of follow-up 412 (11.5%) were diagnosed with AF. In a Cox model adjusted for age, gender, body mass index, hypertension, diabetes mellitus, smoking, estimated glomerular filtration rate, and left ventricular ejection fraction, hazard ratios (HRs) (95% confidence intervals [CIs]) were 1.53 (1.16 to 2.03), 2.03 (1.49 to 2.78), and 2.15 (1.40 to 3.31) when comparing the second, third, and fourth to the first hs-cTnT group, respectively (P for trend <0.000001). The strongest association between hs-cTnT levels and incident AF was found among patients without obstructive CAD (P = 0.024) and adding hs-cTnT to established AF risk factors improved risk classification slightly (ΔROC 0.006, p = 0.044). In conclusion, in patients with suspected stable angina higher levels of hs-cTnT predicted increased risk of incident AF. This was most pronounced in patients without obstructive CAD suggesting an association not mediated by coronary disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.amjcard.2020.03.036DOI Listing
July 2020

Duration of Elevated Heart Rate Is an Important Predictor of Exercise-Induced Troponin Elevation.

J Am Heart Assoc 2020 02 17;9(4):e014408. Epub 2020 Feb 17.

Department of Cardiology Stavanger University Hospital Stavanger Norway.

Background The precise mechanisms causing cardiac troponin (cTn) increase after exercise remain to be determined. The aim of this study was to investigate the impact of heart rate (HR) on exercise-induced cTn increase by using sports watch data from a large bicycle competition. Methods and Results Participants were recruited from NEEDED (North Sea Race Endurance Exercise Study). All completed a 91-km recreational mountain bike race (North Sea Race). Clinical status, ECG, blood pressure, and blood samples were obtained 24 hours before and 3 and 24 hours after the race. Participants (n=177) were, on average, 44 years old; 31 (18%) were women. Both cTnI and cTnT increased in all individuals, reaching the highest level (of the 3 time points assessed) at 3 hours after the race (<0.001). In multiple regression models, the duration of exercise with an HR >150 beats per minute was a significant predictor of both cTnI and cTnT, at both 3 and 24 hours after exercise. Neither mean HR nor mean HR in percentage of maximum HR was a significant predictor of the cTn response at 3 and 24 hours after exercise. Conclusions The duration of elevated HR is an important predictor of physiological exercise-induced cTn elevation. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02166216.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/JAHA.119.014408DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7070191PMC
February 2020

Handling of hemolyzed serum samples in clinical chemistry laboratories: the Nordic hemolysis project.

Clin Chem Lab Med 2019 Oct;57(11):1699-1711

Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway.

Background Some clinical chemistry measurement methods are vulnerable to interference if hemolyzed serum samples are used. The aims of this study were: (1) to obtain updated information about how hemolysis affects clinical chemistry test results on different instrument platforms used in Nordic laboratories, and (2) to obtain data on how test results from hemolyzed samples are reported in Nordic laboratories. Methods Four identical samples containing different degrees of hemolysis were prepared and distributed to 145 laboratories in the Nordic countries. The laboratories were asked to measure the concentration of cell-free hemoglobin (Hb), together with 15 clinical chemistry analytes. In addition, the laboratories completed a questionnaire about how hemolyzed samples are handled and reported. Results Automated detection of hemolysis in all routine patient samples was used by 63% of laboratories, and 88% had written procedures on how to handle hemolyzed samples. The different instrument platforms measured comparable mean Hb concentrations in the four samples. For most analytes, hemolysis caused a homogenous degree of interference regardless of the instrument platform used, except for alkaline phosphatase (ALP), bilirubin (total) and creatine kinase (CK). The recommended cut-off points for rejection of a result varied substantially between the manufacturers. The laboratories differed in how they reported test results, even when they used the same type of instrument. Conclusions Most of the analytes were homogeneously affected by hemolysis, regardless of the instrument used. There is large variation, however, between the laboratories on how they report test results from hemolyzed samples, even when they use the same type of instrument.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1515/cclm-2019-0366DOI Listing
October 2019

Impact of different preanalytical conditions on results of lupus anticoagulant tests.

Int J Lab Hematol 2019 Dec 24;41(6):745-753. Epub 2019 Sep 24.

Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Helse Bergen, Bergen, Norway.

Introduction: The currently recommended preanalytical conditions for lupus anticoagulant (LA) analysis require analyzing samples in fresh or freshly frozen platelet-poor plasma. The aim of this study was to evaluate whether alternative and less cumbersome preanalytical procedures for LA testing give significantly different results compared to recommended conditions.

Materials And Methods: Citrated blood samples were drawn from 29 study participants, 15 with negative and 14 with positive LA results. The samples were processed according to the ISTH guideline for LA testing and compared to several alternative preanalytical conditions. Measurements were performed using the dilute Russell's viper venom time (DRVVT) and silica clotting time (SCT), both screen and confirm, on a STA-R Evolution analyzer. Stability criteria were based upon biological variation.

Results: All DRVVT tests (normalized screen, confirm, and screen/confirm ratio) met the stability criteria for all the preanalytical conditions. The SCT tests (normalized screen, confirm, and screen/confirm ratio) met the stability criteria only when treated according to the ISTH guideline, except for SCT normalized screen/confirm ratio which also met the stability criteria for double-centrifuged aliquoted plasma stored in room temperature for 24 hours and then analyzed "fresh" or after being frozen. One warfarin-treated patient was reclassified from positive to negative for DRVVT after the preanalytical modifications, while 2 of 29 participants became falsely positive for 2 of 8 conditions for SCT.

Conclusions: The DRVVT assays met the criteria for stability for all preanalytical conditions tested, while the SCT assays should be interpreted with caution if the preanalytical guidelines from ISTH are not followed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ijlh.13102DOI Listing
December 2019

Cardiac Troponin Increase After Endurance Exercise.

Circulation 2019 09 3;140(10):815-818. Epub 2019 Sep 3.

Hormone Laboratory, Haukeland University Hospital, Bergen, Norway (K.M.A.).

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/CIRCULATIONAHA.119.042131DOI Listing
September 2019

The rise and fall of the 99th percentile decision limit for cardiac troponins?

Int J Cardiol 2019 08 14;288:25-26. Epub 2019 Mar 14.

Division of Medicine, Akershus University Hospital, Oslo, Norway; Center for Heart Failure Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijcard.2019.02.071DOI Listing
August 2019

Race duration and blood pressure are major predictors of exercise-induced cardiac troponin elevation.

Int J Cardiol 2019 05 23;283:1-8. Epub 2019 Feb 23.

Cardiology Department, Stavanger University Hospital, Stavanger, Norway; Department of Electrical Engineering and Computer Science, University of Stavanger, Stavanger, Norway.

Background: The underlying mechanisms of the exercise-induced increase in cardiac troponins (cTn) are poorly understood. The aim of this study was to identify independent determinants of exercise-induced cTn increase in a large cohort of healthy recreational athletes.

Methods: A total of 1002 recreational cyclists without known cardiovascular disease or medication, participating in a 91-km mountain bike race were included. Median age was 47 years and 78% were males. Blood samples were obtained 24 h prior to, and 3 and 24 h after the race.

Results: Cardiac TnI concentrations increased markedly from baseline [1.9 (1.6-3.0) ng/L] to 3 h after the race [52.1 (32.4-91.8) ng/L], declining at 24 h after the race [9.9 (6.0-20.0) ng/L]. Similarly, cTnT increased from baseline [3.0 (3.0-4.2) ng/L] to 3 h after the race [35.6 (24.4-54.4) ng/L], followed by a decline at 24 h after the race [10.0 (6.9-15.6) ng/L]. The 99th percentile was exceeded at 3 h after the race in 84% (n = 842) of subjects using the cTnI assay and in 92% (n = 925) of study subjects using the cTnT assay. Shorter race duration and higher systolic blood pressure (SBP) at baseline were highly significant (p < 0.001) independent predictors of exercise-induced cTn increase both in bivariate and multivariable analysis. The age, gender, body mass index, training experience and cardiovascular risk of participants were found to be less consistent predictors.

Conclusion: Systolic blood pressure and race duration were consistent predictors of the exercise-induced cTn increase. These variables likely reflect important mechanisms involved in the exercise-induced cTn elevation.

Trial Registration Number: NCT02166216 https://clinicaltrials.gov/ct2/show/NCT02166216.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijcard.2019.02.044DOI Listing
May 2019

Usefulness of Higher Levels of Cardiac Troponin T in Patients With Stable Angina Pectoris to Predict Risk of Acute Myocardial Infarction.

Am J Cardiol 2018 10 4;122(7):1142-1147. Epub 2018 Jul 4.

Haukeland University Hospital, Department of Heart Disease, Bergen, Norway; University of Bergen, Department of Clinical Science, Bergen, Norway.

In patients with stable angina, the association between high-sensitivity cardiac troponin T (hs-cTnT) and incident acute myocardial infarction (AMI), as well as pathophysiologic mechanisms accounting for an adverse prognosis, remain to be determined. We explored the association between hs-cTnT and future AMI among 3,882 patients evaluated for suspected stable angina pectoris and investigated to which extent hs-cTnT attenuated the relations between traditional coronary heart disease (CHD) risk factors and AMI. Associations between increasing hs-cTnT categories (≤3, 4 to 9, 10 to 19, and 20 to 30 ng/L) and risk of AMI were studied by Cox regression. We investigated whether the associations between traditional CHD risk factors and future AMI were influenced by adjusting for hs-cTnT. Median age was 62 years. During median (25th to 75th percentile) 8 (6.4 to 8.7) years of follow-up, 460 (11.8%) experienced an AMI. There was a strong association between hs-cTnT categories and risk of AMI. The relation was somewhat attenuated, but still present, when adjusting for potential confounders, traditional CHD risk factors, previous peripheral vascular disease, and percutaneous coronary intervention or coronary bypass surgery. Moreover, hs-cTnT slightly attenuated the risk relations between traditional CHD risk factors and incident AMI, but each risk factor remained significantly associated with AMI. In conclusion, among patients with suspected stable angina, hs-cTnT was positively related to incident AMI.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.amjcard.2018.06.027DOI Listing
October 2018

A Pathway to National Guidelines for Laboratory Diagnostics of Chronic Kidney Disease - Examples from Diverse European Countries.

EJIFCC 2017 Dec 19;28(4):289-301. Epub 2017 Dec 19.

Laboratoire de Biochimie, CHRU de Montpellier, PhyMedExp, University of Montpellier, France, on behalf of the Société Française de Biologie Clinique (SFBC).

The principal benefit of guidelines is to improve the quality of care received by patients. In the 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease (KDIGO) was released and it is designed to provide information and assist decision making. This review gives a brief overview of a various national CKD guidelines that rely on the newly released KDIGO guidelines. All of the included countries (France, Turkey, Norway and Croatia) are non-English speaking countries and they differ in population and socio economic aspects. Examples shown in this review may provide valuable experience for countries that are in process of creating their national CKD guidelines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5746838PMC
December 2017

The variation in high sensitive cardiac troponin concentration during haemodialysis treatment is not similar to the biological variation observed in stable end stage renal disease patients.

Scand J Clin Lab Invest 2016 Dec 5;76(8):645-652. Epub 2016 Oct 5.

b Laboratory of Clinical Biochemistry , Haukeland University Hospital , Bergen , Norway.

Background: Cardiovascular mortality is high in end stage renal disease (ESRD). This study aimed to: (1) calculate within-week within- and between-subject biological variation (CV and CV) for hs-cTn in ESRD; (2) determine the magnitude of hs-cTn concentration changes during haemodialysis (HD) treatment; and (3) compare the CV and CV to the within and between-subject variation of cTn concentration changes during HD treatments (CV and CV).

Methods: Serum samples were collected from 20 patients before and after 10 consecutive HD treatments. cTn were measured using the hs-cTnT (Roche Diagnostics) and the hs-cTnI (Abbott Diagnostics). The CV, CV CV, CV and CV, were estimated using nested ANOVA.

Results: The within-week data showed hs-cTnT CV, CV and CV of 1.6, 7.3 and 94.4%. Reference change values (RCV) were estimated to -18.7-23.0%. The Index of individuality (II) was 0.08. Corresponding values for hs-cTnI were 5.3, 13.2 and 142.4%, whilst the RCV was -32.5-48.2% and the II was 0.10. The mean concentration of cTn decreased by -6.4% (hs-cTnT) and -7.6% (hs-cTnI) during HD treatment. The CV and CV was 4.2 and 6.3% for hs-cTnT, and 10.7 and 9.4% for hs-cTnI. The RCV was -18.2-5.4% (hs-cTnT) and -39.0-23.8% (hs-cTnI), respectively, and the II-values were 0.7 and 1.3.

Conclusions: The CV and CV are similar to earlier findings. Mean hs-cTn concentrations decreased during HD. The within-subject hs-cTn variation during HD is similar to the between-subject variation, i.e. determining a cut-off value for hs-cTn changes during HD may be useful.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/00365513.2016.1230886DOI Listing
December 2016

Why are clinical practice guidelines not followed?

Clin Chem Lab Med 2016 Jul;54(7):1133-9

Clinical practice guidelines (CPG) are written with the aim of collating the most up to date information into a single document that will aid clinicians in providing the best practice for their patients. There is evidence to suggest that those clinicians who adhere to CPG deliver better outcomes for their patients. Why, therefore, are clinicians so poor at adhering to CPG? The main barriers include awareness, familiarity and agreement with the contents. Secondly, clinicians must feel that they have the skills and are therefore able to deliver on the CPG. Clinicians also need to be able to overcome the inertia of "normal practice" and understand the need for change. Thirdly, the goals of clinicians and patients are not always the same as each other (or the guidelines). Finally, there are a multitude of external barriers including equipment, space, educational materials, time, staff, and financial resource. In view of the considerable energy that has been placed on guidelines, there has been extensive research into their uptake. Laboratory medicine specialists are not immune from these barriers. Most CPG that include laboratory tests do not have sufficient detail for laboratories to provide any added value. However, where appropriate recommendations are made, then it appears that laboratory specialist express the same difficulties in compliance as front-line clinicians.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1515/cclm-2015-0871DOI Listing
July 2016

How to conduct External Quality Assessment Schemes for the pre-analytical phase?

Biochem Med (Zagreb) 2014 15;24(1):114-22. Epub 2014 Feb 15.

Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway ; Noklus (Norwegian Centre for Quality Improvement of Primary Care Laboratories), University of Bergen, Bergen, Norway.

In laboratory medicine, several studies have described the most frequent errors in the different phases of the total testing process, and a large proportion of these errors occur in the pre-analytical phase. Schemes for registration of errors and subsequent feedback to the participants have been conducted for decades concerning the analytical phase by External Quality Assessment (EQA) organizations operating in most countries. The aim of the paper is to present an overview of different types of EQA schemes for the pre-analytical phase, and give examples of some existing schemes. So far, very few EQA organizations have focused on the pre-analytical phase, and most EQA organizations do not offer pre-analytical EQA schemes (EQAS). It is more difficult to perform and standardize pre-analytical EQAS and also, accreditation bodies do not ask the laboratories for results from such schemes. However, some ongoing EQA programs for the pre-analytical phase do exist, and some examples are given in this paper. The methods used can be divided into three different types; collecting information about pre-analytical laboratory procedures, circulating real samples to collect information about interferences that might affect the measurement procedure, or register actual laboratory errors and relate these to quality indicators. These three types have different focus and different challenges regarding implementation, and a combination of the three is probably necessary to be able to detect and monitor the wide range of errors occurring in the pre-analytical phase.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.11613/BM.2014.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3936964PMC
April 2014

PSA measurement and prostate cancer--overdiagnosis and overtreatment?

Tidsskr Nor Laegeforen 2013 Sep;133(16):1711-6

Background: Growing attention is being paid to PSA testing and the risk of overdiagnosis of prostate cancer. This paper investigates how the number of PSA tests has developed over time in Norwegian counties, and relates this development to the incidence of cancer in the various counties and the rates of prostate cancer surgery.

Method: Data on incidence, survival and mortality were obtained from public registers. The numbers of PSA tests carried out were acquired from Norwegian laboratories. The PSA testing rates per county and correlation with prostate cancer incidence rates and surgery rates were surveyed. Developments in Sogn og Fjordane, which has the highest incidence of prostate cancer in Norway, were examined separately. A net-based survey of primary doctors' attitudes and practice was carried out.

Results: The number of PSA tests increased substantially in the period 1999-2011 and in 2011 corresponded to testing of 45% of the total male population aged over 40 in Norway. The number of PSA tests in 2011 correlated with the incidence by county of prostate cancer in the previous period (Pearson's r = 0.41). The correlation between the incidence of cancer and surgical procedures was 0.66. In Sogn og Fjordane, the prostate cancer incidence and survival are rising steeply, while mortality is at the same level as in Norway generally. Primary doctors often comply with their patients' wish for PSA testing and find it difficult not to refer them to specialists if values are elevated.

Interpretation: There is probably a correlation between the increased incidence of prostate cancer and the amount of PSA testing. Compliance with the guidelines for testing should be better and clinicians could practice more watchful waiting with regard to further treatment in cases of elevated PSA values.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4045/tidsskr.13.0023DOI Listing
September 2013

Monitoring renal function in children with Fabry disease: comparisons of measured and creatinine-based estimated glomerular filtration rate.

Nephrol Dial Transplant 2010 May 27;25(5):1507-13. Epub 2009 Dec 27.

Renal Research Group, Institute of Medicine, University of Bergen, Bergen, Norway.

Background: Studies on renal function in children with Fabry disease have mainly been done using estimated creatinine-based glomerular filtration rate (GFR). The aim of this study was to compare estimated creatinine-based GFR (eGFR) with measured GFR (mGFR) in children with Fabry disease and normal renal function.

Methods: Eighty-two examinations were done in 42 children (24 boys, 18 girls) with Fabry disease from three different centres. The mean age was 12.3 years. GFR was measured with iohexol, Cr(51)-EDTA or iothalamate, and the mean mGFR was 108 ml/min/1.73 m(2).

Results: The widely used original Schwartz formula (1976) overestimated GFR substantially by 50.6 ml/min/1.73 m(2) with a very low accuracy, whereas the new abbreviated Schwartz formula (2009) showed relatively good performances with a mean GFR overestimation of 5.3 ml/min/1.73 m(2) and 79% of the eGFR calculated within 20% of mGFR, thus being only slightly superior to the Counahan-Barratt formula. However, less than half of the eGFR calculated by the new abbreviated Schwartz equation were within 10% of the mGFR. When repeated measurements were performed, mGFR showed less variation than eGFR.

Conclusions: The new abbreviated Schwartz formula should replace the original Schwartz formula in the routine follow-up of children with Fabry disease. The current creatinine-based GFR formulas are all hampered by low accuracy in the 'creatinine-blind' GFR range, and early progressive disease may be missed. Supplemental mGFR is, therefore, recommended in patients where changes in GFR have potential impact on important treatment regimens. Cystatin C-based GFR formulas remain to be validated in Fabry children.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ndt/gfp658DOI Listing
May 2010
-->