Øystein Karlstad
Research professor
Contact
Send email {model.translations.sendEmailTo} Oystein.Karlstad@fhi.no
Department
Responsibilities
Drug use, safety and effect. Pharmacoepidemiology.
Projects and publications
- Paz Lopez-Doriga Ruiz, Lars Bakke Hindenes, Øystein Karlstad, Kjersti Nøkleby, Haakon Eduard Meyer, Aurélie Mailhac, Rickard Ljung, Reimar W. Thomsen, Kari Furu, (2025). Trends in the use of drugs with weight-loss effect: Scandinavian study from 2017 to 2023. Diabetes, obesity and metabolism s. 2901-2905. doi: 10.1111/dom.16291
- Sarah M. Baxter, Lars Christian Lund, Jacob H. Andersen, Thomas H. Brix, Laszlo Hegedüs, Miyuki Hsing-Chun Hsieh, Chris Tzu-Ting Su, Michael Chun-Yuan Cheng, Zoe Chi-Jui Chang, Edward Chia-Cheng Lai, Swaleh Hussain, Cherry Chu, Tara Gomes, Tony Antoniou, Antoine Eskander, Zachary Bouck, Mina Tadrous, Sungho Bea, Eun-Young Choi, Ju-Young Shin, Karin Modig, Mats Talbäck, Rickard Ljung, Hanne Løvdal Gulseth, Øystein Karlstad, Blánaid Hicks, Anton Pottegård, (2025). Glucagon-Like Peptide 1 Receptor Agonists and Risk of Thyroid Cancer: An International Multisite Cohort Study. Thyroid s. 69-78. doi: 10.1089/thy.2024.0387
- Lotte Rasmussen, Jacob Harbo Andersen, Øystein Karlstad, Diego Hernan Giunta, Marie Linder, Kari Furu, Anton Pottegård, (2024). Early uptake of semaglutide for type 2 diabetes in Scandinavia and characteristics of initiators in Denmark: A register-based drug utilization study. Diabetes, obesity and metabolism s. 5479-5482. doi: 10.1111/dom.15876
- Mette Bliddal, Emma Bjørk, Øystein Karlstad, Jonas W. Wastesson, Rikke Wesselhoeft, Rune Lindahl-Jacobsen, Anton Pottegård, Maarten Jan Wensink, Lotte Rasmussen, (2024). Comparison of sociodemographic factors, healthcare utilisation by general practitioner visits, somatic hospital admissions, and medication use in Norway, Sweden, and Denmark. Annals of Epidemiology s. 1-7. doi: 10.1016/j.annepidem.2024.07.004
- Anders Hviid, Tuomo A. Nieminen, Nicklas Pihlström, Nina Gunnes, Jesper Dahl, Øystein Karlstad, Hanne Løvdal Gulseth, Anders Sundström, Anders Husby, Jørgen Vinsløv Hansen, Rickard Ljung, Petteri Hovi, (2024). Booster vaccination with SARS-CoV-2 mRNA vaccines and myocarditis in adolescents and young adults: a Nordic cohort study. European Heart Journal s. 1327-1335. doi: 10.1093/eurheartj/ehae056
- Claudia Bruno, Carolyn E. Cesta, Vidar Hjellvik, Sinna Pilgaard Ulrichsen, Marte-Helene Bjørk, Buket Öztürk Esen, Malcolm B. Gillies, Mika Gissler, Alys Havard, Øystein Karlstad, Maarit Leinonen, Mette Nørgaard, Sallie-Anne Pearson, Johan Reutfors, Kari Furu, Jacqueline Mallory Cohen, Helga Zoega, (2024). Antipsychotic use during pregnancy and risk of specific neurodevelopmental disorders and learning difficulties in children: a multinational cohort study. EClinicalMedicine doi: 10.1016/j.eclinm.2024.102531
- Adrienne Y. L. Chan, Le Gao, Miyuki Hsing-Chun Hsieh, Lars J. Kjerpeseth, Raquel Avelar, Tobias Banaschewski, Amy Hai Yan Chan, David Coghill, Jacqueline M. Cohen, Mika Gissler, Jeff Harrison, Patrick Ip, Øystein Karlstad, Wallis C. Y. Lau, Maarit K. Leinonen, Wing Cheong Leung, Tzu-Chi Liao, Johan Reutfors, Shih-Chieh Shao, Emily Simonoff, Kathryn Choon Beng Tan, Katja Taxis, Andrew Tomlin, Carolyn E. Cesta, Edward Chia-Cheng Lai, Helga Zoega, Kenneth K. C. Man, Ian C. K. Wong, (2024). Maternal diabetes and risk of attention-deficit/hyperactivity disorder in offspring in a multinational cohort of 3.6 million mother–child pairs. Nature Medicine s. 1416-1423. doi: 10.1038/s41591-024-02917-8
- Paz Lopez-Doriga Ruiz, Øystein Karlstad, Kjersti Nøkleby, Kristina Barbara Slåtsve, Hanne Løvdal Gulseth, Haakon E. Meyer, Kari Anne Sveen, Elisabeth Qvigstad, Kari Furu, (2024). Pharmacological treatment of obesity in adults in Norway 2004–2022. Diabetes, obesity and metabolism s. 2102-2110. doi: 10.1111/dom.15515
- Wenche Nystad, Vidar Hjellvik, Inger Kristin Larsen, Trude Eid Robsahm, Erik Reidar Sund, Steinar Krokstad, Laila Arnesdatter Hopstock, Anne Sameline Grimsgaard, Arnulf Langhammer, Jørgen Gustav Bramness, Torbjørn Wisløff, Simon Lergenmuller, Knut Eirik Dalene, Haakon Eduard Meyer, Kristin Holvik, Jon Helgeland, Øystein Karlstad, Inger Ariansen, (2023). National health registries – a ‘goldmine’ for studying non-communicable disease occurrence in Norway – the NCDNOR project. Scandinavian Journal of Public Health doi: 10.1177/14034948231214580
- Lars Jøran Kjerpeseth, Vidar Hjellvik, Hanne Løvdal Gulseth, Øystein Karlstad, Paz Lopez-Doriga Ruiz, Knut-Arne Wensaas, Kari Furu, (2023). Prevalence and treatment of gestational diabetes in Norway 2010–2020. Diabetes Research and Clinical Practice s. 1-8. doi: 10.1016/j.diabres.2023.111025
- Lars Jøran Kjerpeseth, Carolyn E. Cesta, Kari Furu, Anders Engeland, Mika Gissler, Hanne Løvdal Gulseth, Øystein Karlstad, Maarit Leinonen, Laura Pazzagli, Helga Zoega, Jacqueline Mallory Cohen, (2023). Metformin Versus Insulin and Risk of Major Congenital Malformations in Pregnancies With Type 2 Diabetes: A Nordic Register-Based Cohort Study. Diabetes Care s. 1556-1564. doi: 10.2337/dc23-0256
- Chaitra Srinivas, Øystein Karlstad, Hein Stigum, Kari Furu, Carolyn E. Cesta, Johan Reutfors, Jacqueline M. Cohen, (2023). Trajectories of ADHD medication use before, during, and after pregnancy: A population-based study from Norway and Sweden. Pharmacoepidemiology and Drug Safety s. 1152-1160. doi: 10.1002/pds.5654
- J. J. Komen, N. B. Hunt, A. Pottegård, P. Hjemdahl, B. Wettermark, M. Olesen, M. Bennie, T. Mueller, R. Carragher, Øystein Karlstad, Lars Jøran Kjerpeseth, O. H. Klungel, T. Forslund, (2023). Heterogeneity after harmonisation: A retrospective cohort study of bleeding and stroke risk after the introduction of direct oral anticoagulants in four Western European countries. Pharmacoepidemiology and Drug Safety s. 1223-1232. doi: 10.1002/pds.5650
- Jonas Minet Kinge, Joseph L. Dieleman, Øystein Karlstad, Ann Kristin Knudsen, Søren Toksvig Klitkou, Simon I. Hay, Theo Vos, Christopher J L Murray, Stein Emil Vollset, (2023). Disease-specific health spending by age, sex, and type of care in Norway: a national health registry study. BMC Medicine doi: 10.1186/s12916-023-02896-6
- Håkon Ihle-Hansen, Håkon Bøås, German Tapia, Guri Hagberg, Hege Beathe Ihle-Hansen, Jacob Dag Berild, Randi Marie Selmer, Øystein Karlstad, Hanne Løvdal Gulseth, Inger Ariansen, (2023). Stroke After SARS-CoV-2 mRNA Vaccine: A Nationwide Registry Study. Stroke s. e190-e193. doi: 10.1161/STROKEAHA.122.040430
- Anders Husby, Hanne Løvdal Gulseth, Petteri Hovi, Jørgen Vinsløv Hansen, Nicklas Pihlstrøm, Nina Gunnes, Tommi Härkänen, Jesper Dahl, Øystein Karlstad, Tiina Heliö, Lars Køber, Rickard Ljung, Anders Hviid, (2023). Clinical outcomes of myocarditis after SARS-CoV-2 mRNA vaccination in four Nordic countries: population based cohort study. BMJ Medicine s. 1-9. doi: 10.1136/bmjmed-2022-000373
- Mette Reilev, Peter Bjødstrup Jensen, Lise Skov Ranch, Alexander Egeberg, Kari Furu, Karin Gembert, David Hagg, Ulrike Haug, Øystein Karlstad, Johan Reutfors, Wiebke Schäfer, Sarina Schwartz, Elisabeth Smits, Emily Holthius, Ron Herings, Gianluca Trifirò, Ursula Kirchmayer, Alessandro Cesare Rosa, Valeria Belleudi, Rosa Gini, Henrik Støvring, Jesper Hallas, (2023). Methodology of the brodalumab assessment of hazards: a multicentre observational safety (BRAHMS) study. BMJ Open s. 1-11. doi: 10.1136/bmjopen-2022-066057
- Reza Ghiasvand, Leon Alexander Mclaren Berge, Bettina Kulle, Jo Steinson Stenehjem, Trond Heir, Øystein Karlstad, Asta Juzenienne, Inger Kristin Larsen, Adele C. Green, Marit Bragelien Veierød, Trude Eid Robsahm, (2022). Use of antihypertensive drugs and risk of cutaneous melanoma: A nationwide nested case-control study. International Journal of Epidemiology s. 887-898. doi: 10.1093/ije/dyac223
- Jacqueline Mallory Cohen, Silje Alvestad, Carolyn E. Cesta, Marte-Helene Bjørk, Maarit Leinonen, Mette Nørgaard, Kristjana Einarsdóttir, Anders Engeland, Mika Gissler, Øystein Karlstad, Kari Klungsøyr, Ingvild Odsbu, Johan Reutfors, Randi Marie Selmer, Torbjörn Tomson, Sinna Pilgaard Ulrichsen, Helga Zoega, Kari Furu, (2022). Comparative Safety of Antiseizure Medication Monotherapy for Major Malformations. Annals of Neurology doi: 10.1002/ana.26561
- Jacqueline Mallory Cohen, Chaitra Srinivas, Kari Furu, Carolyn E. Cesta, Johan Reutfors, Øystein Karlstad, (2022). Prevalence trends and individual patterns of ADHD medication use in pregnancy in Norway and Sweden, 2010–2019. European Journal of Clinical Pharmacology s. 173-180. doi: 10.1007/s00228-022-03428-6
- Paz Lopez-Doriga Ruiz, Nina Gunnes, Jon Michael Gran, Øystein Karlstad, Randi Marie Selmer, Jesper Dahl, Håkon Bøås, Richard Aubrey White, Aurora Christine Hofman, Trine Hessevik Paulsen, Sara Sofie Viksmoen Watle, Anette Hylen Ranhoff, Geir Bukholm, Hanne Løvdal Gulseth, German Tapia, (2022). Short-term safety of COVID-19 mRNA vaccines with respect to all-cause mortality in the older population in Norway. Vaccine s. 323-332. doi: 10.1016/j.vaccine.2022.10.085
- Lennart Kyllesø, Robert Løvsletten Smith, Birgit Malene Tovik Wollmann, Øystein Karlstad, Ole Andreassen, Espen Molden, (2022). Metabolite Profiling of Clozapine in Patients Switching Versus Maintaining Treatment: A Retrospective Pilot Study. Journal of Clinical Psychopharmacology s. 470-474. doi: 10.1097/JCP.0000000000001585
- Aino Rantala, German Tapia, Maria Christine Magnus, Lars Christian Mørch Stene, Jouni J. K. Jaakkola, Ketil Størdal, Øystein Karlstad, Wenche Nystad, (2022). Maternal antibiotic use and infections during pregnancy and offspring asthma: the Norwegian Mother, Father and Child Cohort Study and a nationwide register cohort. European Journal of Epidemiology (EJE) s. 983-992. doi: 10.1007/s10654-022-00897-y
- Øystein Karlstad, Petteri Hovi, Anders Husby, Tommi Härkänen, Randi Marie Selmer, Nicklas Pihlström, Jørgen Vinsløv Hansen, Hanna Nohynek, Nina Gunnes, Anders Sundström, Jan Wohlfahrt, Tuomo A. Nieminen, Maria Grünewald, Hanne Løvdal Gulseth, Anders Hviid, Rickard Ljung, (2022). SARS-CoV-2 Vaccination and Myocarditis in a Nordic Cohort Study of 23 Million Residents. JAMA cardiology s. 600-612. doi: 10.1001/jamacardio.2022.0583
- Joris J. Komen, Anton Pottegård, Aukje K. Mantel-Teeuwisse, Tomas Forslund, Paul Hjemdahl, Björn Wettermark, Jesper Hallas, Morten Olesen, Marion Bennie, Tanja Mueller, Raymond Carragher, Øystein Karlstad, Lars Jøran Kjerpeseth, Olaf H. Klungel, (2022). Oral anticoagulants in patients with atrial fibrillation at low stroke risk: a multicentre observational study. European Heart Journal s. 3528-3538. doi: 10.1093/eurheartj/ehac111
- Kristin Holvik, Vidar Hjellvik, Øystein Karlstad, Nina Gunnes, Mari Hoff, Grethe Seppola Tell, Haakon Eduard Meyer, (2022). Contribution of an extensive medication-based comorbidity index (Rx-Risk) in explaining the excess mortality after hip fracture in older Norwegians: A NOREPOS cohort study. BMJ Open s. 1-11. doi: 10.1136/bmjopen-2021-057823
- Oskar Halfdanarson, Jacqueline Mallory Cohen, Øystein Karlstad, Carolyn E. Cesta, Marte-Helene Bjørk, Siri Eldevik Håberg, Kristjana Einarsdottir, Kari Furu, Mika Gissler, Vidar Hjellvik, Helle Kieler, Maarit Leinonen, Mette Nørgaard, Buket Öztürk Essen, Sinna Pilgaard Ulrichsen, Johan Reutfors, Helga Zoega, (2021). Antipsychotic use in pregnancy and risk of attention/deficit-hyperactivity disorder and autism spectrum disorder: a Nordic cohort study. Evidence-Based Mental Health s. 54-62. doi: 10.1136/ebmental-2021-300311
- Jacqueline Mallory Cohen, Carolyn E. Cesta, Lars Jøran Kjerpeseth, Maarit K. Leinonen, Oskar Halfdanarson, Øystein Karlstad, Pär Karlsson, Morten Andersen, Kari Furu, Vidar Hjellvik, (2021). A common data model for harmonization in the Nordic Pregnancy Drug Safety Studies (NorPreSS). Norsk Epidemiologi s. 117-135. doi: 10.5324/nje.v29i1-2.4053
- Kari Furu, Ellen Barth Aares, Vidar Hjellvik, Øystein Karlstad, (2021). Hormonal contraceptive use in Norway, 2006-2020, by contraceptive type, age and county: A nationwide register-based study. Norsk Epidemiologi s. 55-62. doi: 10.5324/nje.v29i1-2.4046
- Joris J. Komen, Anton Pottegård, Aukje K. Mantel-Teeuwisse, Tomas Forslund, Paul Hjemdahl, Björn Wettermark, Maja Hellfritzsch, Jesper Hallas, Morten Olesen, Marion Bennie, Tanja Mueller, Annemarie Voss, Tania Schink, Ulrike Haug, Bianca Kollhorst, Øystein Karlstad, Lars Jøran Kjerpeseth, Olaf H. Klungel, (2021). Persistence and adherence to non-vitamin K antagonist oral anticoagulant treatment in patients with atrial fibrillation across five Western European countries. Europace s. 1722-1730. doi: 10.1093/europace/euab091
- Anton Pottegård, Lars Lund, Øystein Karlstad, Jesper Dahl, Morten Andersen, Jesper Hallas, Øjvind Lidegaard, German Tapia, Hanne Løvdal Gulseth, Paz Lopez-Doriga Ruiz, Sara Sofie Viksmoen Watle, Anders Mikkelsen, Lars Pedersen, Henrik Toft Sørensen, Reimar Wernich Thomsen, Anders Hviid, (2021). Arterial events, venous thromboembolism, thrombocytopenia, and bleeding after vaccination with Oxford-AstraZeneca ChAdOx1-S in Denmark and Norway: population based cohort study. BMJ Open doi: 10.1136/bmj.n1114
- Lennart Kyllesø, Robert Løvsletten Smith, Øystein Karlstad, Ole A. Andreassen, Espen Molden, (2021). Absolute and Dose-Adjusted Serum Concentrations of Clozapine in Patients Switching vs. Maintaining Treatment: An Observational Study of 1979 Patients. CNS Drugs s. 999-1008. doi: 10.1007/s40263-021-00847-4
- Helene Kildegaard Jensen, Lotte Rasmussen, Kari Furu, Øystein Karlstad, Marie Linder, Carolyn E. Cesta, Anton Pottegård, (2021). Use of non‐insulin antidiabetic drugs in children and young adults – a Scandinavian drug utilization study from 2010‐2019. British Journal of Clinical Pharmacology s. 4470-4475. doi: 10.1111/bcp.14867
- Wenche Nystad, Vidar Hjellvik, Inger Kristin Larsen, Inger Kristine Holtermann Ariansen, Eyvind Helland, Knut Ivar Johansen, Johanne Gulbrandsen, Hanne Løvdal Gulseth, Helena Niemi Eide, Siri Eldevik Håberg, Øystein Karlstad, Inger Johanne Bakken, (2020). Underlying conditions in adults with COVID-19. Tidsskrift for Den norske legeforening (Tidsskriftet) doi: 10.4045/tidsskr.20.0512
- Leon Alexander Berge, Bettina Kulle, Jo S. Stenehjem, Trond Heir, Øystein Karlstad, Asta Juzeniene, Reza Ghiasvand, Inger Kristin Larsen, Adele C. Green, Marit Bragelien Veierød, Trude Eid Robsahm, (2020). Use of immunomodulating drugs and risk of cutaneous melanoma: A nationwide nested case-control study. Clinical Epidemiology s. 1389-1401. doi: 10.2147/CLEP.S269446
- Nathalie Charlotte Støer, Edoardo Botteri, G. Hege Thoresen, Øystein Karlstad, Elisabete Weiderpass, Søren Friis, Anton Pottegård, Bettina Kulle, (2020). Drug Use and Cancer Risk: A Drug-Wide Association Study (DWAS) in Norway. Cancer Epidemiology, Biomarkers and Prevention doi: 10.1158/1055-9965.EPI-20-1028
- Johan Reutfors, Carolyn Cesta, Jacqueline Mallory Cohen, Brian T Bateman, Ruth Brauer, Kristjana Einarsdottir, Anders Engeland, Kari Furu, Mika Gissler, Alys Havard, Sonia Hernandez-Diaz, Krista F. Huybrechts, Øystein Karlstad, Maarit Leinonen, Jiong Li, Kenneth K. C. Man, Laura Pazzagli, Andrea Schaffer, Tania Schink, Zixuan Wang, Yongfu Yu, Helga Zoega, Gabriella Bröms, (2020). Antipsychotic drug use in pregnancy: A multinational study from ten countries. Schizophrenia Research s. 106-115. doi: 10.1016/j.schres.2020.03.048
- Jacqueline Mallory Cohen, Carolyn Cesta, Kari Furu, Kristjana Einarsdottir, Mika Gissler, Alys Havard, Sonia Hernandez-Diaz, Krista F Huybrechts, Helle Kieler, Maarit Leinonen, Jiong Li, Johan Reutfors, Andrea Schaffer, Randi Marie Selmer, Yongfu Yu, Helga Zoega, Øystein Karlstad, (2020). Prevalence trends and individual patterns of antiepileptic drug use in pregnancy 2006-2016: A study in the five Nordic countries, United States, and Australia. Pharmacoepidemiology and Drug Safety s. 913-922. doi: 10.1002/pds.5035
- Jacqueline Mallory Cohen, Randi Marie Selmer, Kari Furu, Øystein Karlstad, (2020). Interrupted time series analysis to assess changes in prescription filling around conception and implications for exposure misclassification. Pharmacoepidemiology and Drug Safety s. 745-749. doi: 10.1002/pds.4974
- Lennart Kyllesø, Robert Løvsletten Smith, Øystein Karlstad, Ole Andreas Andreassen, Espen Molden, (2020). Undetectable or subtherapeutic serum levels of antipsychotic drugs preceding switch to clozapine. Nature NPJ Schizophrenia doi: 10.1038/s41537-020-0107-7
- Hasse Melbye, Jon Helgeland, Øystein Karlstad, Inger Ariansen, Arnulf Langhammer, Torbjørn Wisløff, Per Nafstad, Wenche Nystad, (2020). Is the disease burden from COPD in Norway falling off? A study of time trends in three different data sources. The International Journal of Chronic Obstructive Pulmonary Disease s. 323-334. doi: 10.2147/COPD.S235106
- Aino K. Rantala, Maria Christine Magnus, Øystein Karlstad, Hein Stigum, Siri Eldevik Håberg, Per Nafstad, Wenche Nystad, Jouni J. K. Jaakkola, (2020). Is the association of early day care attendance with childhood asthma explained by underlying susceptibility?. Epidemiology s. 451-458. doi: 10.1097/EDE.0000000000001163
- Carolyn E. Cesta, Jacqueline Mallory Cohen, Laura Pazzagli, Brian T. Bateman, Gabriella Bröms, Kristjana Einarsdottir, Kari Furu, Alys Havard, Anna Heino, Sonia Hernandez-Diaz, Krista F. Huybrechts, Øystein Karlstad, Helle Kieler, Jiong Li, Maarit K. Leinonen, Hanne Løvdal Gulseth, Duong D. Tran, Yongfu Yu, Helga Zoega, Ingvild Odsbu, (2019). Antidiabetic medication use during pregnancy: an international utilization study. BMJ Open Diabetes Research & Care s. 1-12. doi: 10.1136/bmjdrc-2019-000759
- Lars Jøran Kjerpeseth, Randi Marie Selmer, Inger Ariansen, Øystein Karlstad, Hanne Ellekjær, Eva Skovlund, (2019). Comparative effectiveness of warfarin, dabigatran, rivaroxaban and apixaban in nonvalvular atrial fibrillation: A nationwide pharmacoepidemiological study. PLOS ONE s. 1-18. doi: 10.1371/journal.pone.0221500
- Ingvild Bruun Mikalsen, Ingvild Dalen, Øystein Karlstad, Geir Egil Eide, Maria Christine Magnus, Wenche Nystad, Knut Øymar, (2019). Airway symptoms and atopy in young children prescribed asthma medications: A large‐scale cohort study. Pediatric Pulmonology s. 1557-1566. doi: 10.1002/ppul.24437
- Bettina Kulle, Nathalie Charlotte Støer, Jan Ivar Martinsen, Giske Ursin, Elisabete Weiderpass, G. Hege Thoresen, Karen A. Boldingh Debernard, Øystein Karlstad, Anton Pottegard, Søren Friis, (2019). Identification of potential carcinogenic and chemopreventive effects of prescription drugs: A protocol for a Norwegian registry-based study. BMJ Open s. 1-7. doi: 10.1136/bmjopen-2018-028504
- Stine Dydensborg Sander, Anne-Marie Nybø Andersen, Joseph A. Murray, Øystein Karlstad, Steffen Husby, Ketil Størdal, (2019). Association Between Antibiotics in the First Year of Life and Celiac Disease. Gastroenterology s. 2217-2229. doi: 10.1053/j.gastro.2019.02.039
- Vidar Hjellvik, Marie L. de Bruin, Sven Ove Samuelsen, Øystein Karlstad, Morten Andersen, Jari Haukka, Peter Vestergaard, Frank de Vries, Kari Furu, (2019). Adjusting for unmeasured confounding using validation data: Simplified two-stage calibration for survival and dichotomous outcomes. Statistics in Medicine doi: 10.1002/sim.8131
- Kasper Bruun Kristensen, Øystein Karlstad, Jaana E Martikainen, Anton Pottegård, Jonas W Wastesson, Helga Zoega, Morten Schmidt, (2019). Nonaspirin Nonsteroidal Antiinflammatory Drug Use in the Nordic Countries from a Cardiovascular Risk Perspective, 2000–2016: A Drug Utilization Study. Pharmacotherapy s. 150-160. doi: 10.1002/phar.2217
- Maria Christine Magnus, Øystein Karlstad, Christine Louise Parr, Christian Page, Per Nafstad, Per Magnus, Stephanie J London, Allen J Wilcox, Wenche Nystad, Siri Eldevik Håberg, (2019). Maternal history of miscarriages and measures of fertility in relation to childhood asthma. Thorax s. 106-113. doi: 10.1136/thoraxjnl-2018-211886
- Sudha R Raman, Kenneth K. C. Man, Shahram Bahmanyar, Anick Berard, Scott Bilder, Takoua Boukhris, Greta Bushnell, Stephen Crystal, Kari Furu, Yea-Huei KaoYang BS Pharm, Øystein Karlstad, Helle Kieler, Kiyoshi Kubota, Edward Chia-Cheng Lai, Jaana E. Martikainen, Géric Maura Pharm, Nicholas Moore, Dolores Montero, Hidefumi Nakamura, Anke Neumann, Virginia Pate, Anton Pottegård, Nicole L. Pratt, Elizabeth E. Roughead, Diego Macias Saint-Gerons, Til Stürmer, Chien-Chou Su, Helga Zoega, Miriam C. J. M. Sturkenbroom, Esther W. Chan, David Coghill, Patrick Ip, Ian C. K. Wong, (2018). Trends in attention-deficit hyperactivity disorder medication use: a retrospective observational study using population-based databases. The Lancet Psychiatry s. 824-835. doi: 10.1016/S2215-0366(18)30293-1
- Jonas W Wastesson, Jaana E Martikainen, Helga Zoega, Morten Schmidt, Øystein Karlstad, Anton Pottegård, (2018). Trends in Use of Paracetamol in the Nordic Countries. Basic & Clinical Pharmacology & Toxicology s. 301-307. doi: 10.1111/bcpt.13003
- Christine Louise Parr, Maria Christine Magnus, Øystein Karlstad, Kristin Holvik, Nicolai Andre Lund-Blix, Margaretha Haugen, Christian Page, Per Nafstad, Per Magne Ueland, Stephanie J. London, Siri Eldevik Håberg, Wenche Nystad, (2018). Vitamin A and D intake in pregnancy, infant supplementation, and asthma development: The Norwegian Mother and Child Cohort. American Journal of Clinical Nutrition s. 789-798. doi: 10.1093/ajcn/nqy016
- Ingvild Bruun Mikalsen, Øystein Karlstad, Kari Furu, Knut Øymar, (2018). Forskrivning av legemidler mot astma til barn i perioden 2004–15. Tidsskrift for Den norske legeforening (Tidsskriftet) s. 345-351. doi: 10.4045/tidsskr.17.0227
- Maria Christine Magnus, Rosalind J. Wright, Espen Røysamb, Christine Louise Parr, Øystein Karlstad, Christian Page, Per Nafstad, Siri Eldevik Håberg, Stephanie J. London, Wenche Nystad, (2018). Association of Maternal Psychosocial Stress with Increased Risk of Asthma Development in Offspring. American Journal of Epidemiology s. 1199-1209. doi: 10.1093/aje/kwx366
- Inga Marie Johannsdottir, Jon Håvard Loge, Cecilie E. Kiserud, Øystein Karlstad, Svetlana Skurtveit, (2018). Increased prescription rates of anxiolytics and hypnotics to survivors of cancer in childhood, adolescence, and young adulthood — A population-based study. Pediatric Blood & Cancer doi: 10.1002/pbc.26860
- Krista F Huybrechts, Gabriella Bröms, Lotte Brix Christensen, Kristjana Einarsdottir, Anders Engeland, Kari Furu, Mika Gissler, Sonia Hernandez-Diaz, Pär Karlsson, Øystein Karlstad, Helle Kieler, Anna-Maria Lahesmaa-Korpinen, Helen Mogun, Mette Nørgaard, Johan Reutfors, Henrik Toft Sørensen, Helga Zoega, Brian T Bateman, (2017). Association between methylphenidate and amphetamine use in pregnancy and risk of congenital malformations: A cohort study from the international pregnancy safety study consortium. JAMA psychiatry s. 167-175. doi: 10.1001/jamapsychiatry.2017.3644
- Anna But, Marie L de Bruin, Marloes T Bazelier, Vidar Hjellvik, Morten Andersen, Anssi Auvinen, Jakob Starup-Linde, Marjanka K Schmidt, Kari Furu, Frank de Vries, Øystein Karlstad, Nils Ekström, Jari Haukka, (2017). Cancer risk among insulin users: comparing analogues with human insulin in the CARING five-country cohort study. Diabetologia s. 1691-1703. doi: 10.1007/s00125-017-4312-5
- Øystein Karlstad, Kari Furu, Camilla Stoltenberg, Siri Eldevik Håberg, Inger Johanne Bakken, (2017). ADHD treatment and diagnosis in relation to children's birth month: Nationwide cohort study from Norway. Scandinavian Journal of Public Health s. 343-349. doi: 10.1177/1403494817708080
- Kari Furu, Øystein Karlstad, Helga Zoega, Jaana E Martikainen, Shahram Bahmanyar, Helle Kieler, Anton Pottegård, (2017). Utilization of Stimulants and Atomoxetine for Attention-Deficit/Hyperactivity Disorder among 5.4 million Children Using Population-based Longitudinal Data. Basic & Clinical Pharmacology & Toxicology s. 373-379. doi: 10.1111/bcpt.12724
- Inga Marie Johannsdottir, Øystein Karlstad, Jon Håvard Loge, Sophie Dorothea Fosså, Cecilie E. Kiserud, Svetlana Skurtveit, (2017). Prescriptions of Antidepressants to Survivors of Cancer in Childhood, Adolescence, and Young Adulthood: A Population-Based Study. Journal of Adolescent and Young Adult Oncology s. 120-126. doi: 10.1089/jayao.2016.0041
- Christine Louise Parr, Maria Christine Magnus, Øystein Karlstad, Alice Margaretha Haugen, Helga Refsum, Per Magne Ueland, Adrian Mccann, Per Nafstad, Siri Eldevik Håberg, Wenche Nystad, Stephanie J London, (2017). Maternal folate intake during pregnancy and childhood asthma in a population-based cohort. American Journal of Respiratory and Critical Care Medicine s. 221-228. doi: 10.1164/rccm.201604-0788OC
- Maria Christine Magnus, Siri Eldevik Håberg, Per Magnus, Anders Engeland, Per Nafstad, Øystein Karlstad, Wenche Nystad, (2016). Pre-eclampsia and childhood asthma. European Respiratory Journal s. 1622-1630. doi: 10.1183/13993003.00673-2016
- Øystein Karlstad, Helga Zoega, Kari Furu, Shahram Bahmanyar, Jaana E Martikainen, Helle Kieler, Anton Pottegård, (2016). Use of drugs for ADHD among adults-a multinational study among 15.8 million adults in the Nordic countries. European Journal of Clinical Pharmacology s. 1507-1514. doi: 10.1007/s00228-016-2125-y
- Maria Christine Magnus, Øystein Karlstad, Siri Eldevik Håberg, Per Nafstad, George Davey Smith, Wenche Nystad, (2016). Prenatal and infant paracetamol exposure and development of asthma: The Norwegian Mother and Child Cohort Study. International Journal of Epidemiology s. 512-522. doi: 10.1093/ije/dyv366
- Maria Christine Magnus, Øystein Karlstad, Øivind Midttun, Siri Eldevik Håberg, Gro Tunheim, Christine Louise Parr, Per Nafstad, Stephanie J London, Roy Miodini Nilsen, Per Magne Ueland, Wenche Nystad, (2016). Maternal plasma total neopterin and kynurenine/tryptophan levels during pregnancy in relation to asthma development in the offspring. Journal of Allergy and Clinical Immunology s. 1319-1325.e4. doi: 10.1016/j.jaci.2016.02.032
- Ingeborg Hartz, Svetlana Skurtveit, Anne Kjersti Myhrene Steffenak, Øystein Karlstad, Marte Handal, (2016). Psychotropic drug use among 0-17 year olds during 2004-2014: a nationwide prescription database study. BMC Psychiatry doi: 10.1186/s12888-016-0716-x
- Andreas Mellbye, Øystein Karlstad, Svetlana Skurtveit, Petter Chr. Borchgrevink, Olav Magnus Fredheim, (2016). The duration and course of opioid therapy in patients with chronic non-malignant pain. Acta Anaesthesiologica Scandinavica s. 128-137. doi: 10.1111/aas.12594
- Knut Øymar, Ingvild Bruun Mikalsen, Kari Furu, Wenche Nystad, Øystein Karlstad, (2015). Prescription patterns of inhaled corticosteroids for preschool children - A Norwegian register study. Pediatric Allergy and Immunology s. 655-661. doi: 10.1111/pai.12429
- Heleen K Bronsveld, Bas ter Braak, Øystein Karlstad, Peter Vestergaard, Jakob Starup-Linde, Marloes T. Bazelier, Marie L de Bruin, Anthonius De Boer, Christine L.E. Siezen, Bob van de Water, Jan Willem van der Laan, Marjanka K Schmidt, (2015). Treatment with insulin (analogues) and breast cancer risk in diabetics; a systematic review and meta-analysis of in vitro, animal and human evidence. Breast Cancer Research doi: 10.1186/s13058-015-0611-2
- Maria Christine Magnus, Siri Eldevik Håberg, Øystein Karlstad, Per Nafstad, Stephanie J London, Wenche Nystad, (2015). Grandmother's smoking when pregnant with the mother and asthma in the grandchild: the Norwegian Mother and Child Cohort Study. Thorax s. 237-243. doi: 10.1136/thoraxjnl-2014-206438
- Andreas Mellbye, Øystein Karlstad, Svetlana Skurtveit, Petter Chr. Borchgrevink, Olav Magnus Fredheim, (2014). Co-morbidity in persistent opioid users with chronic non-malignant pain in Norway. European Journal of Pain s. 1083-1093. doi: 10.1002/j.1532-2149.2014.00449.x
- Øystein Karlstad, Kari Furu, Svetlana Skurtveit, Randi Selmer, (2014). Prescribing of drugs for attention-deficit hyperactivity disorder in opioid maintenance treatment patients in Norway. European Addiction Research s. 59-65. doi: 10.1159/000353969
- Øystein Karlstad, Jakob Starup-Linde, Peter Vestergaard, Vidar Hjellvik, Marloes T Bazelier, Marjanka K Schmidt, Morten Andersen, Anssi Auvinen, Jari Haukka, Kari Furu, Frank de Vries, Marie L De Bruin, (2013). Use of insulin and insulin analogs and risk of cancer - systematic review and meta-analysis of observational studies. Current Drug Safety s. 333-348. doi: 10.2174/15680266113136660067
- Jakob Starup-Linde, Øystein Karlstad, Stine Aistrup Eriksen, Peter Vestergaard, Heleen K Bronsveld, Frank de Vries, Morten Andersen, Anssi Auvinen, Jari Haukka, Vidar Hjellvik, Marloes T Bazelier, Anthonius de Boer, Kari Furu, Marie L De Bruin, (2013). CARING (CAncer Risk and INsulin analoGues): the association of diabetes mellitus and cancer risk with focus on possible determinants - a systematic review and a meta-analysis. Current Drug Safety s. 296-332. doi: 10.2174/15748863113086660071
- Øystein Karlstad, Per Nafstad, Aage Tverdal, Svetlana Skurtveit, Kari Furu, (2012). Comorbidities in an asthma population 8-29 years old: a study from the Norwegian Prescription Database. Pharmacoepidemiology and Drug Safety s. 1045-1052. doi: 10.1002/pds.2233
- Kari Furu, Vidar Hjellvik, Ingeborg Hartz, Øystein Karlstad, Svetlana Skurtveit, Hege Salvesen Blix, Hanne Strøm, Randi Marie Selmer, (2018). Legemiddelbruk hos barn og unge i Norge 2008–2017.
- Ragnhild Ørstavik, Kristin Gustavson, Nina Rohrer-Baumgartner, Guido Biele, Kari Furu, Øystein Karlstad, Ted Reichborn-Kjennerud, Tiril Cecilie Borge, Heidi Aase, (2016). ADHD i Norge: en statusrapport.
- Christian Lie Berg, Øystein Karlstad, Milada Mahic, Ingvild Odsbu, (2014). Reseptregisteret 2009-2013. The Norwegian prescription database 2009-2013.
- Christian Lie Berg, Øystein Karlstad, Milada Mahic, Ingvild Odsbu, (2013). Reseptregisteret 2008-2012. The Norwegian prescription database 2008-2012.
- Øystein Karlstad, (2011). Epidemiology of asthma drug use in children, adolescents and young adults in Norway.
- Claudia Bruno, Carolyn E. Cesta, Vidar Hjellvik, Sinna Pilgaard Ulrichsen, Marte-Helene Bjørk, Buket Öztürk Esen, Malcolm B. Gillies, Mika Gissler, Alys Havard, Øystein Karlstad, Maarit Leinonen, Mette Nørgaard, Sallie-Anne Pearson, Johan Reutfors, Kari Furu, Jacqueline Mallory Cohen, Helga Zoega, (2025). Corrigendum to Antipsychotic use during pregnancy and risk of specific neurodevelopmental disorders and learning difficulties in children: a multinational cohort study [eClinicalMedicine 70 (2024) 102531/DOI: 10.1016/j.eclinm.2024.102531] (eClinicalMedicine (2024) 70, (S258953702400110X), (10.1016/j.eclinm.2024.102531)). EClinicalMedicine doi: 10.1016/j.eclinm.2025.103139
- Chaitra Srinivas, Øystein Karlstad, Hein Stigum, Kari Furu, Carolyn E. Cesta, Johan Reutfors, Vidar Hjellvik, Jennifer A. Hutcheon, Jacqueline Mallory Cohen, (2024). ADHD medication use in pregnancy and risk of miscarriage.
- Chaitra Srinivas, Øystein Karlstad, Hein Stigum, Kari Furu, Carolyn E. Cesta, Johan Reutfors, Jennifer A. Hutcheon, Jacqueline Mallory Cohen, (2024). Timing and duration of ADHD medication use in pregnancy and risk of preterm birth.
- T. Berge, Øyvind Erik Næss, Torbjørn Wisløff, L. H. Mortensen, Eva Skovlund, Øystein Karlstad, Vidar Hjellvik, Lars Jøran Kjerpeseth, Grace M. Egeland, Jannicke Igland, Grethe S. Tell, Emilie R. Hegelund, Mariam Anjum, Ingrid E. Christophersen, M Myrstad, A. Tveit, Inger Ariansen, (2023). Registry tool for stroke prevention in atrial fibrillation in Norway – RegTool AFNOR.
- Jacqueline Mallory Cohen, Maria Christine Magnus, Kari Furu, Øystein Karlstad, Chaitra Srinivas, Olga Basso, Siri Eldevik Håberg, (2023). ADHD and induced abortion in young women: A population-based study from Norway.
- Chaitra Srinivas, Øystein Karlstad, Hein Stigum, Kari Furu, Carolyn E. Cesta, Johan Reutfors, Jennifer Hutcheon, Jacqueline Mallory Cohen, (2023). Risk of preterm birth associated with ADHD medication use in pregnancy.
- Kristin Holvik, Vidar Hjellvik, Øystein Karlstad, Nina Gunnes, Mari Hoff, Grethe S. Tell, Haakon Eduard Meyer, (2022). Implementing a medication-based index to account for comorbidity in pharmacoepidemiologic studies: The Rx-Risk Comorbidity Index.
- Christine Louise Parr, Wenche Nystad, Øystein Karlstad, Knut Asbjørn Alexander Øymar, Arnulf Langhammer, Per Nafstad, Torbjørn Wisløff, (2022). Ten-year trends of national healthcare costs of asthma, allergic rhinitis, and atopic eczema in 3 million Norwegians. Allergy. European Journal of Allergy and Clinical Immunology doi: 10.1111/all.15225
- Angela Lupattelli, Øystein Karlstad, Anders Engeland, Lars Småbrekke, Kristine Olsen, Aina Øvrebust, Marit Waaseth, (2021). The Norwegian Society for Pharmacoepidemiology. Norsk Epidemiologi s. 5-6. doi: 10.5324/nje.v29i1-2.4039
- Knut Asbjørn Alexander Øymar, Øystein Karlstad, Ketil Størdal, (2021). Har anbefalinger om endring av behandling effekt?. Tidsskrift for Den norske legeforening (Tidsskriftet) s. 1-3. doi: 10.4045/tidsskr.21.0437
- Kristin Holvik, Vidar Hjellvik, Øystein Karlstad, Nina Gunnes, Mari Hoff, Grethe Seppola Tell, Haakon Eduard Meyer, (2020). The contribution of an extensive medication-based comorbidity index to explain excess mortality after hip fracture in Norway. Therapeutic Advances in Musculoskeletal Disease (TAMD) s. 53-53. doi: 10.1177/1759720X20969289
- Kristian Svendsen, Øystein Karlstad, Lars Småbrekke, (2018). Lower cancer incidence-warfarin effect or immortal time bias?. JAMA Internal Medicine s. 585-585. doi: 10.1001/jamainternmed.2018.0370.
- Kristian Svendsen, Øystein Karlstad, Lars Småbrekke, (2018). To the editor. JAMA Internal Medicine s. 585-585. doi: 10.1001/jamainternmed.2018.0370
- Ingeborg Hartz, Svetlana Skurtveit, Anne Kjersti Myhrene Steffenak, Øystein Karlstad, Marte Handal, (2015). Psychotropic drug use among 0-17 year olds during 2004-2013: a nationwide prescription database study.
- Ingeborg Hartz, Svetlana Skurtveit, Anne Kjersti Myhrene Steffenak, Øystein Karlstad, Marte Handal, (2014). Psychotropic drug use among 0-17 year olds during 2004-2013: a Nationwide prescription database study.
- Ingeborg Hartz, Svetlana Skurtveit, Anne Kjersti Myhrene Steffenak, Øystein Karlstad, Marte Handal, (2014). Psychotropic drug use among 0-17 year olds during 2004-2013: a Nationwide prescription database study. Norsk Epidemiologi, Supplement s. 57-57.
- Ingeborg Hartz, Svetlana Skurtveit, Øystein Karlstad, Anne Kjersti Myhrene Steffenak, Marte Handal, (2014). Psychotropic drug use among 0-17 year olds during 2004-2013: a nationwide prescription database study.
- Jakob Starup-Linde, Peter Vestergaard, Øystein Karlstad, Stine Aistrup Eriksen, Heleen K Bronsveld, Frank de Vries, Anthonius de Boer, Marie L. de Bruin, (2013). CARING: diabetes mellitus and risk of cancer - a systematic review and meta-analysis. Diabetologia s. S183-S183.
- Kari Furu, Øystein Karlstad, Svetlana Skurtveit, Randi Selmer, (2012). Treatment of ADHD with Psychostimulants in Patients on Opioid Maintenance Therapy (OMT) in Norway – A Nationwide Study. Pharmacoepidemiology and Drug Safety s. 424-424.