Kjetil Røysland

Førsteamanuensis - Avdeling for biostatistikk
Bilde av Kjetil Røysland
English version of this page
Telefon +47 22851015
Rom Rom 2175 D
Brukernavn
Besøksadresse Domus Medica
Postadresse Postboks 1122 Blindern 0317 OSLO
Andre tilknytninger Institutt for pedagogikk (Student)

My main research interest lies in developing better methods for evaluation of treatment effects with clinical health registry data. From a methodological perspective, the focus is on  causal inference techniques that are suitable for survival data. This involves several mathematical concepts like counting processes, stochastic differential equations and even som graph theory.

Publikasjoner

  • Ryalen, Pål Christie; Stensrud, Mats Julius; Fosså, Sophie Dorothea & Røysland, Kjetil (2020). Causal inference in continuous time: an example on prostate cancer therapy. Biostatistics.  ISSN 1465-4644.  21(1), s 172- 185 . doi: 10.1093/biostatistics/kxy036 Fulltekst i vitenarkiv.
  • Aalen, Odd O.; Stensrud, Mats Julius; Didelez, Vanessa; Daniel, Rhian; Røysland, Kjetil & Strohmaier, Susanne (2019). Time-dependent mediators in survival analysis: Modeling direct and indirect effects with the additive hazards model. Biometrical Journal.  ISSN 0323-3847.  s 1- 18 . doi: 10.1002/bimj.201800263
  • Hausken, John; Fretland, Åsmund Avdem; Edwin, Bjørn; Andersen, Marit Helen; Dagenborg, Vegar Johansen; Bjørnelv, Gudrun Maria Waaler; Kristiansen, Ronny; Røysland, Kjetil; Kvarstein, Gunnvald & Tønnessen, Tor Inge (2019). Intravenous patient-controlled analgesia versus thoracic epidural analgesia after open liver surgery: a prospective, randomized, controlled noninferiority trial. Annals of Surgery.  ISSN 0003-4932.  270(2), s 193- 199 . doi: 10.1097/SLA.0000000000003209
  • Latysheva, Anna; Emblem, Kyrre Eeg; Brandal, Petter; Vik-Mo, Einar O.; Pahnke, Jens; Røysland, Kjetil; Hald, John K & Server, Andrés (2019). Dynamic susceptibility contrast and diffusion MR imaging identify oligodendroglioma as defined by the 2016 WHO classification for brain tumors: histogram analysis approach. Neuroradiology.  ISSN 0028-3940.  61(5), s 545- 555 . doi: 10.1007/s00234-019-02173-5 Fulltekst i vitenarkiv. Vis sammendrag
  • Ryalen, Pål Christie; Stensrud, Mats Julius & Røysland, Kjetil (2019). The additive hazard estimator is consistent for continuous-time marginal structural models. Lifetime Data Analysis.  ISSN 1380-7870.  25(4), s 611- 638 . doi: 10.1007/s10985-019-09468-y
  • Stensrud, Mats Julius; Ryalen, Pål Christie & Røysland, Kjetil (2019). Sufficient Cause Interaction for Time-to-event Outcomes. Epidemiology.  ISSN 1044-3983.  30(2), s 189- 196 . doi: 10.1097/EDE.0000000000000958
  • Stensrud, Mats Julius; Røysland, Kjetil & Ryalen, Pål Christie (2019). On null hypotheses in survival analysis. Biometrics.  ISSN 0006-341X.  75(4), s 1276- 1287 . doi: 10.1111/biom.13102
  • Aalen, Odd O.; Gran, Jon Michael; Røysland, Kjetil; Stensrud, Mats Julius & Strohmaier, Susanne (2018). Feedback and Mediation in Causal Inference Illustrated by Stochastic Process Models. Scandinavian Journal of Statistics.  ISSN 0303-6898.  45(1), s 62- 86 . doi: 10.1111/sjos.12286
  • Ryalen, Pål Christie; Stensrud, Mats Julius & Røysland, Kjetil (2018). Transforming cumulative hazard estimates. Biometrika.  ISSN 0006-3444.  105(4), s 905- 916 . doi: 10.1093/biomet/asy035 Fulltekst i vitenarkiv.
  • Gran, Jon Michael; Hoff, Rune; Røysland, Kjetil; Ledergerber, Bruno; Young, James & Aalen, Odd O. (2017). Estimating the treatment effect on the treated under time-dependent confounding in an application to the Swiss HIV Cohort Study. Journal of the Royal Statistical Society, Series C: Applied Statistics.  ISSN 0035-9254.  67(1), s 103- 125 . doi: 10.1111/rssc.12221 Fulltekst i vitenarkiv.
  • Stensrud, Mats Julius; Aalen, Odd O.; Valberg, Morten & Røysland, Kjetil (2017). Exploring selection bias by causal frailty models: The magnitude matters. Epidemiology.  ISSN 1044-3983.  28(3), s 379- 386 . doi: 10.1097/EDE.0000000000000621
  • Aalen, Odd O.; Røysland, Kjetil; Gran, Jon Michael; Kouyos, Roger & Lange, Theis (2016). Can we believe the DAGs? A comment on the relationship between causal DAGs and mechanisms. Statistical Methods in Medical Research.  ISSN 0962-2802.  25(5), s 2294- 2314 . doi: 10.1177/0962280213520436
  • Hovdenes, Jan; Røysland, Kjetil; Nielsen, Niklas; Kjærgaard, Jesper; Wanscher, Michael; Hassager, Christian; Wetterslev, Jørn; Cronberg, Tobias; Erlinge, David; Friberg, Hans; Gasche, Yvan; Horn, Janneke; Kuiper, Michael; Pellis, Tommaso; Stammet, Pascal; Wise, Matthew P.; Åneman, Anders & Bugge, Jan F (2016). A low body temperature on arrival at hospital following out-of-hospital-cardiac-arrest is associated with increased mortality in the TTM-study. Resuscitation.  ISSN 0300-9572.  107, s 102- 106 . doi: 10.1016/j.resuscitation.2016.08.011
  • Lund-Johansen, Fridtjof; de la Rosa-Carrillo, Daniel; Mehta, Adi; Sikorski, Krzysztof; Inngjerdingen, Marit; Kalina, Tomáš; Røysland, Kjetil; De Souza, Gustavo Antonio; Bradbury, Andrew R.M.; Lecrevisse, Quentin & Stuchly, Jan (2016). MetaMass, a tool for meta-analysis of subcellular proteomics data. Nature Methods.  ISSN 1548-7091.  13(10), s 837- 840 . doi: 10.1038/nmeth.3967
  • Aalen, Odd O.; Cook, Richard J. & Røysland, Kjetil (2015). Does Cox analysis of a randomized survival study yield a causal treatment effect?. Lifetime Data Analysis.  ISSN 1380-7870.  21(4), s 579- 593 . doi: 10.1007/s10985-015-9335-y
  • Strohmaier, Susanne; Røysland, Kjetil; Hoff, Rune; Borgan, Ørnulf; Pedersen, Terje Rolf & Aalen, Odd O. (2015). Dynamic path analysis - a useful tool to investigate mediation processes in clinical survival trials. Statistics in Medicine.  ISSN 0277-6715.  34(29), s 3866- 3887 . doi: 10.1002/sim.6598
  • Nygård, Mari; Røysland, Kjetil; Campbell, Suzanne & Dillner, Joakim (2014). Comparative effectiveness study on human papillomavirus detection methods used in the cervical cancer screening programme. BMJ Open.  ISSN 2044-6055. . doi: 10.1136/bmjopen-2013-003460
  • Sanchez-Niubo, Albert; Aalen, Odd O.; Domingo-Salvany, Antonia; Amundsen, Ellen Johanna; Fortiana, Josep & Røysland, Kjetil (2013). A multi-state model to estimate incidence of heroin use. BMC Medical Research Methodology.  ISSN 1471-2288.  13 . doi: 10.1186/1471-2288-13-4 Vis sammendrag
  • Aalen, Odd O.; Røysland, Kjetil; Gran, Jon Michael & Ledergerber, Bruno (2012). Causality, mediation and time: a dynamic viewpoint. Journal of the Royal Statistical Society: Series A (Statistics in Society).  ISSN 0964-1998.  175(4), s 831- 861 . doi: 10.1111/j.1467-985X.2011.01030.x
  • Røysland, Kjetil (2012). COUNTERFACTUAL ANALYSES WITH GRAPHICAL MODELS BASED ON LOCAL INDEPENDENCE. Annals of Statistics.  ISSN 0090-5364.  40(4), s 2162- 2194 . doi: 10.1214/12-AOS1031
  • Tropé, Ameli Ellen Claesdotter; Sjøborg, Katrine Dønvold; Nygård, Mari; Røysland, Kjetil; Campbell, Suzanne; Alfsen, Glenny Cecilie & Jonassen, Christine M (2012). Cytology and Human Papillomavirus Testing 6 to 12 Months after ASCUS or LSIL Cytology in Organized Screening To Predict High-Grade Cervical Neoplasia between Screening Rounds. Journal of Clinical Microbiology.  ISSN 0095-1137.  50(6), s 1927- 1935 . doi: 10.1128/JCM.00265-12
  • Røysland, Kjetil (2011). A martingale approach to continuous time marginal structural models. Bernoulli.  ISSN 1350-7265.  17(3), s 895- 915 . doi: 10.3150/10-BEJ303
  • Røysland, Kjetil (2011). Frames generated by actions of countable discrete groups. Transactions of the American Mathematical Society.  ISSN 0002-9947.  363(1), s 95- 108
  • Røysland, Kjetil; Gran, Jon Michael; Ledergerber, Bruno; von Wyl, Viktor; Young, James A. & Aalen, Odd O. (2011). Analyzing direct and indirect effects of treatment using dynamic path analysis applied to data from the Swiss HIV Cohort Study. Statistics in Medicine.  ISSN 0277-6715.  30(24), s 2947- 2958 . doi: 10.1002/sim.4324
  • Gjessing, Håkon K.; Røysland, Kjetil; Aalen, Odd O. & Pena, Edsel A (2010). Recurrent events and the exploding Cox model. Lifetime Data Analysis.  ISSN 1380-7870.  16(4), s 525- 546 . doi: 10.1007/s10985-010-9180-y
  • Gran, Jon Michael; Røysland, Kjetil; Wolbers, Marcel; Didelez, Vanessa; Sterne, Jonathan AC; Ledergerber, Bruno; Furrer, Hansjakob; von Wyl, Viktor & Aalen, Odd O. (2010). A sequential Cox approach for estimating the causal effect of treatment in the presence of time-dependent confounding applied to data from the Swiss HIV Cohort Study. Statistics in Medicine.  ISSN 0277-6715.  29(26), s 2757- 2768 . doi: 10.1002/sim.4048
  • Røysland, Kjetil (2008). Symmetries in projective multiresolution analyses. Journal of Fourier Analysis and Applications.  ISSN 1069-5869.  14(2), s 267- 285
  • Røysland, Kjetil & Dutkay, Dorin (2008). Covariant Representations for Matrix-valued Transfer Operators. Integral equations and operator theory.  ISSN 0378-620X.  62(3), s 383- 410 . doi: 10.1007/s00020-008-1623-4
  • Dutkay, Dorin & Røysland, Kjetil (2007). The algebra of harmonic functions for a matrix-valued transfer operator. Journal of Functional Analysis.  ISSN 0022-1236.  252(2), s 734- 762 . doi: 10.1016/j.jfa.2007.04.014

Se alle arbeider i Cristin

  • Fretland, Åsmund Avdem; Hausken, Jon; Edwin, B; Andersen, Marit Helen; Dagenborg, Vegar Johansen; Kristiansen, Ronny; Røysland, Kjetil; Kvarstein, Gunnvald & Tønnessen, Tor-Inge (2018). Does ketorolac have an opioid sparing effect after open liver resection? Data from the Oslo-COMET trial.
  • Frank, Anna-Simone Josefine; Lupattelli, Angela; Røysland, Kjetil & Nordeng, Hedvig Marie Egeland (2017). PATTERNS AND PREDICTORS OF HYPOTHYROID MEDICATION USE IN RELATION TO PREGNANCY: A DRUG UTILIZATION STUDY.
  • Frank, Anna-Simone Josefine; Lupattelli, Angela; Røysland, Kjetil & Nordeng, Hedvig Marie Egeland (2017). Patterns and Predictors of Hypothyroid Medication Use in Relation to Pregnancy: A Drug Utilization Study.
  • Frank, Anna-Simone Josefine; Lupattelli, Angela; Røysland, Kjetil & Nordeng, Hedvig Marie Egeland (2017). Risk factors for discontinuation of hypothyroid medication in early pregnancy -- a study from the Norwegian Mother and Child Cohort Study and the Medical Birth Registry of Norway.
  • Røysland, Kjetil (2010). A Marginal Structural Model in Continuous Time.
  • Røysland, Kjetil (2010). A marginal structural model in continuous time.
  • Røysland, Kjetil (2010). A marginal structural model in continuous time.
  • Røysland, Kjetil (2010). Interventions with identifiable consequences.
  • Røysland, Kjetil (2009). A marginal structural model in continuous time.
  • Røysland, Kjetil (2009). Transfer operators and harmonic bundle maps.
  • Røysland, Kjetil (2006). Transfer operators on bundle maps.

Se alle arbeider i Cristin

Publisert 16. jan. 2012 17:01 - Sist endret 13. des. 2019 12:44

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