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Ann Helen Kristoffersen

Observed names: A. Kristoffersen, A.H. Kristoffersen, Ann H Kristoffersen, Kristoffersen, Ann Helen
Observed institutions: Oslo University Hospital, University Hospital Centre Zagreb, OsloMet – Oslo Metropolitan University, University of Oslo, Haukeland University Hospital, Ege University, Haraldsplass Diakonale Sykehus, National Institute of Health Dr. Ricardo Jorge, University of Bergen
ORCID: 0000-0002-4223-3959
Observed ORCID: 0000-0002-4223-3959
OpenAlex ID: A5071520774
How to conduct External Quality Assessment Schemes for the pre-analytical phase?
2014 · Gunn B.B. Kristensen, Kristin Moberg Aakre, et al. · Biochemia Medica · 51
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The European Biological Variation Study (EuBIVAS): Biological Variation Data for Coagulation Markers Estimated by a Bayesian Model
2021 · Aasne K Aarsand, Ann Helen Kristoffersen, et al. · Clinical Chemistry · 32
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Presentation and formatting of laboratory results: a narrative review on behalf of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group “postanalytical phase” (WG-POST)
2021 · Janne Cadamuro, Andreas Hillarp, et al. · Critical Reviews in Clinical Laboratory Sciences · 30
Estimates of Within-Subject Biological Variation of Protein C, Antithrombin, Protein S Free, Protein S Activity, and Activated Protein C Resistance in Pregnant Women
2017 · Ann H Kristoffersen, Per H Petersen, et al. · Clinical Chemistry · 27
Is D-dimer used according to clinical algorithms in the diagnostic work-up of patients with suspicion of venous thromboembolism? A study in six European countries
2016 · Ann Helen Kristoffersen, Eva Ajzner, et al. · Thrombosis Research · 22
Quality of Warfarin Therapy and Quality of Life are Improved by Self-Management for Two Years
2019 · Una Ørvim Sølvik, Elisabeth Løkkebø, et al. · Thrombosis and Haemostasis · 20
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Impact of different preanalytical conditions on results of lupus anticoagulant tests
2019 · Ann Helen Kristoffersen, Ida Jansrud Hammer, et al. · International Journal of Laboratory Hematology · 14
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Pre-analytical practices for routine coagulation tests in European laboratories. A collaborative study from the European Organisation for External Quality Assurance Providers in Laboratory Medicine (EQALM)
2019 · Ann Helen Kristoffersen, Anne V. Stavelin, et al. · Clinical Chemistry and Laboratory Medicine (CCLM) · 14
An international study of how laboratories handle and evaluate patient samples after detecting an unexpected APTT prolongation
2015 · Éva Ajzner, Dunja Rogic, et al. · Clinical Chemistry and Laboratory Medicine (CCLM) · 13
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Within-subject biological variation of activated partial thromboplastin time, prothrombin time, fibrinogen, factor VIII and von Willebrand factor in pregnant women
2018 · Ann Helen Kristoffersen, Per Hyltoft Petersen, et al. · Clinical Chemistry and Laboratory Medicine (CCLM) · 12
Systematic review and meta-analysis of within-subject and between-subject biological variation data of coagulation and fibrinolytic measurands
2023 · Martine J. Hollestelle, Ann Helen Kristoffersen, et al. · Clinical Chemistry and Laboratory Medicine (CCLM) · 9
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Concentration of fibrin monomer in pregnancy and during the postpartum period
2019 · Ann Helen Kristoffersen, Per Hyltoft Petersen, et al. · Annals of Clinical Biochemistry International Journal of Laboratory Medicine · 8
Efficiency, efficacy and subjective user satisfaction of alternative laboratory report formats. An investigation on behalf of the Working Group for Postanalytical Phase (WG-POST), of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM)
2022 · Janne Cadamuro, Johannes Winzer, et al. · Clinical Chemistry and Laboratory Medicine (CCLM) · 7
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A national surveillance program for evaluating new reagent lots in medical laboratories
2022 · Anne Elisabeth Solsvik, Ann Helen Kristoffersen, et al. · Clinical Chemistry and Laboratory Medicine (CCLM) · 7
Pre- and post-test probabilities of venous thromboembolism and diagnostic accuracy of D-dimer, estimated by European clinicians working in emergency departments
2017 · Ann Helen Kristoffersen, Eva Ajzner, et al. · Thrombosis Research · 7
Self-management of warfarin therapy
2015 · Una Ørvim Sølvik, Elisabeth Sellevoll Løkkebø, et al. · Tidsskrift for Den norske legeforening · 7
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Practical handling of hemolytic, icteric and lipemic samples for coagulation testing in European laboratories. A collaborative survey from the European Organisation for External Quality Assurance Providers in Laboratory Medicine (EQALM)
2025 · Ann Helen Kristoffersen, Martine J. Hollestelle, et al. · Clinical Chemistry and Laboratory Medicine (CCLM) · 3
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An international study on activated partial thromboplastin time prolongation. Part 2: Interpretative commenting
2022 · Josep Miquel Bauça, Éva Ajzner, et al. · Clinica Chimica Acta · 2
Warfarin monitoring in nursing homes assessed by case histories. Do recommendations and electronic alerts affect judgements?
2017 · Reyes Serrano Teruel, Geir Thue, et al. · Scandinavian Journal of Primary Health Care · 2
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Polyvinylpyrrolidone induced artefactual prolongation of activated partial thromboplastin times in intravenous drug users with renal failure
2016 · A.H. Kristoffersen, T.K. Bjånes, et al. · Journal of Thrombosis and Haemostasis · 2
Short-term biological variation of coagulation and fibrinolytic measurands
2025 · Martine J. Hollestelle, Ann Helen Kristoffersen, et al. · Clinical Chemistry and Laboratory Medicine (CCLM) · 1
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An international study on activated partial thromboplastin time prolongation. Part 1: Analytical results
2022 · Josep Miquel Bauça, Éva Ajzner, et al. · Clinica Chimica Acta · 1
Availability and characteristics of external quality assessment (EQA) schemes for measurement of hemolysis, icterus and lipemia (HIL) in routine coagulation testing, a collaborative study from the European Organisation for External Quality Assurance in Laboratory Medicine (EQALM)
2026 · Ann Helen Kristoffersen, Martine J. Hollestelle, et al. · Clinical Chemistry and Laboratory Medicine (CCLM)
PB1284 Availability of External quality assessment (EQA) schemes for measurement of hemolysis, icterus and lipemia (HIL) in routine coagulation testing
2026 · Ann Helen Kristoffersen, Martine van Essen-Hollestelle, et al. · Research and Practice in Thrombosis and Haemostasis
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Decreasing Platelet Aggregation Despite Increasing Soluble P-selectin during Pregnancy in Women with and without Heterozygous Factor V Leiden Mutation
2026 · Margunn Bye Tøsdal, Turid Helen Felli Lunde, et al. · Thrombosis and Haemostasis
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Works count: 33
Citation count: 291
H-index: 10
I10-index: 10
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