Harald Weedon-Fekjær
Position: Researcher (Statistician), PhD
Phone: +47 975 70 081

Academic interests

  • Statistical modeling and simulation
  • Applied statistics
  • Statistical computing and software
  • Teaching of statistics

Ongoing work

  • Evaluating the potential effect of mammography screening on breast cancer mortality (main project)
  • Estimating the natural progression of breast cancer and DCIS and its implications
  • Developing good methods for Cancer mortality predictions
  • Studying breast cancer epidemiology


Higher education and employment history

  • PhD in medical statistics, University of Oslo, Norway (2008)
  • Master in mathematical statistics, University of Oslo, Norway (1999)


  • "Breast cancer tumor growth estimated through mammography screening data” (by Weedon-Fekjær et. al., 2008) was selected as article of the year 2008 by the Norwegian Epidemiological Association.  


  • Part of US NCI-sponsored CISNET (The Cancer Intervention and Surveillance Modeling Network) consortium though Dana-Farber Cancer Institute / Harvard University (USA).  


For full CV for Harald Weedon-Fekjær see: 
For more on Harald Weedon-Fekjær see:

University home page: http://www.med.uio.no/imb/personer/vit/hfe/index.html

Key publications:

  1. “Modern mammography screening and breast cancer mortality: population study”, Weedon-Fekjær et. al., BMJ 2014
  2. “Understanding recent invasive breast cancer incidence trends using Age-Period-Cohort analysis and  registry data on mammography screening and hormone treatment use”, Weedon-Fekjær et. al., BMJ 2012
  3. “Breast cancer tumor growth estimated through mammography screening data”, Weedon-Fekjær et. al., Breast Cancer Research 2008
  4. “Prediction of cancer incidence in the Nordic countries up to years 2022; A collaborative study of the five Nordic Cancer Registries”, Møller, Fekjær et al., 2002

Author network for Harald Weedon-Fekjær by COREMINE medical

Publications 2017

Sundby ØH, Høiseth LØ, Mathiesen I, Weedon-Fekjær H, Sundhagen JO, Hisdal J (2017)
The acute effects of lower limb intermittent negative pressure on foot macro- and microcirculation in patients with peripheral arterial disease
PLoS One, 12 (6), e0179001
PubMed 28591174

Trewin CB, Strand BH, Weedon-Fekjær H, Ursin G (2017)
Changing patterns of breast cancer incidence and mortality by education level over four decades in Norway, 1971-2009
Eur J Public Health, 27 (1), 160-166
PubMed 28177482

Publications 2016

Boldingh MI, Maniaol AH, Brunborg C, Weedon-Fekjær H, Verschuuren JJ, Tallaksen CM (2016)
Increased risk for clinical onset of myasthenia gravis during the postpartum period
Neurology, 87 (20), 2139-2145
PubMed 27770065

Sundby ØH, Høiseth LØ, Mathiesen I, Jørgensen JJ, Weedon-Fekjær H, Hisdal J (2016)
Application of intermittent negative pressure on the lower extremity and its effect on macro- and microcirculation in the foot of healthy volunteers
Physiol Rep, 4 (17)
PubMed 27630148

Publications 2015

Berner K, Hall KS, Monge OR, Weedon-Fekjær H, Zaikova O, Bruland ØS (2015)
Prognostic factors and treatment results of high-grade osteosarcoma in norway: a scope beyond the "classical" patient
Sarcoma, 2015, 516843
PubMed 25784831

Fosså SD, Dahl AA, Langhammer A, Weedon-Fekjær H (2015)
Cancer patients' participation in population-based health surveys: findings from the HUNT studies
BMC Res Notes, 8, 649
PubMed 26541408

Gangnon RE, Sprague BL, Stout NK, Alagoz O, Weedon-Fekjær H, Holford TR, Trentham-Dietz A (2015)
The contribution of mammography screening to breast cancer incidence trends in the United States: an updated age-period-cohort model
Cancer Epidemiol Biomarkers Prev, 24 (6), 905-12
PubMed 25787716

Löffeler S, Weedon-Fekjaer H, Wang-Hansen MS, Sebakk K, Hamre H, Haug ES, Fosså SD (2015)
"Natural course" of disease in patients with metastatic castrate-resistant prostate cancer: Survival and prognostic factors without life-prolonging treatment
Scand J Urol, 49 (6), 440-445
PubMed 26139461

Zaikova O, Sundby Hall K, Styring E, Eriksson M, Trovik CS, Bergh P, Bjerkehagen B, Skorpil M, Weedon-Fekjaer H, Bauer HC (2015)
Referral patterns, treatment and outcome of high-grade malignant bone sarcoma in Scandinavia--SSG Central Register 25 years' experience
J Surg Oncol, 112 (8), 853-60
PubMed 26482729

Publications 2014

Solheim O, Gershenson DM, Tropé CG, Rokkones E, Sun CC, Weedon-Fekjaer H, Fosså SD (2014)
Prognostic factors in malignant ovarian germ cell tumours (The Surveillance, Epidemiology and End Results experience 1978-2010)
Eur J Cancer, 50 (11), 1942-50
PubMed 24857045

Weedon-Fekjær H, Romundstad PR, Vatten LJ (2014)
Modern mammography screening and breast cancer mortality: population study
BMJ, 348, g3701
PubMed 24951459

Publications 2012

Weedon-Fekjær H, Bakken K, Vatten LJ, Tretli S (2012)
Understanding recent trends in incidence of invasive breast cancer in Norway: age-period-cohort analysis based on registry data on mammography screening and hormone treatment use
BMJ, 344, e299
PubMed 22290099

Publications 2011

Weedon-Fekjær H (2011)
Effectiveness of population-based service screening with mammography for women ages 40 to 49 years: evaluation of the Swedish Mammography Screening in Young Women (SCRY) Cohort
Cancer, 118 (4), 1169; author reply 1170-1
PubMed 21766290

Publications 2010

Weedon-Fekjaer H, Tretli S, Aalen OO (2010)
Estimating screening test sensitivity and tumour progression using tumour size and time since previous screening
Stat Methods Med Res, 19 (5), 507-27
PubMed 20356856

Publications 2009

Weedon-Fekjaer H, Sørum R, Brenn MK (2009)
Hormone therapy use may explain recent results regarding tumor regression
Arch Intern Med, 169 (10), 996-7
PubMed 19468094

Publications 2008

Weedon-Fekjaer H, Lindqvist BH, Vatten LJ, Aalen OO, Tretli S (2008)
Estimating mean sojourn time and screening sensitivity using questionnaire data on time since previous screening
J Med Screen, 15 (2), 83-90
PubMed 18573776

Weedon-Fekjaer H, Lindqvist BH, Vatten LJ, Aalen OO, Tretli S (2008)
Breast cancer tumor growth estimated through mammography screening data
Breast Cancer Res, 10 (3), R41
PubMed 18466608

Publications 2006

Andersson G, Noack T, Seierstad A, Weedon-Fekjaer H (2006)
The demographics of same-sex marriages in Norway and Sweden
Demography, 43 (1), 79-98
PubMed 16579209

Fosen J, Borgan O, Weedon-Fekjaer H, Aalen OO (2006)
Dynamic analysis of recurrent event data using the additive hazard model
Biom J, 48 (3), 381-98
PubMed 16845903

Wibe A, Carlsen E, Dahl O, Tveit KM, Weedon-Fekjaer H, Hestvik UE, Wiig JN, Norwegian Rectal Cancer Group (2006)
Nationwide quality assurance of rectal cancer treatment
Colorectal Dis, 8 (3), 224-9
PubMed 16466564

Publications 2005

Møller B, Weedon-Fekjaer H, Hakulinen T, Tryggvadóttir L, Storm HH, Talbäck M, Haldorsen T (2005)
The influence of mammographic screening on national trends in breast cancer incidence
Eur J Cancer Prev, 14 (2), 117-28
PubMed 15785315

Møller B, Weedon-Fekjaer H, Haldorsen T (2005)
Empirical evaluation of prediction intervals for cancer incidence
BMC Med Res Methodol, 5, 21
PubMed 15949034

Weedon-Fekjaer H, Vatten LJ, Aalen OO, Lindqvist B, Tretli S (2005)
Estimating mean sojourn time and screening test sensitivity in breast cancer mammography screening: new results
J Med Screen, 12 (4), 172-8
PubMed 16417693

Publications 2004

Aalen OO, Fosen J, Weedon-Fekjaer H, Borgan O, Husebye E (2004)
Dynamic analysis of multivariate failure time data
Biometrics, 60 (3), 764-73
PubMed 15339300