Publications 2024

Johannessen A, Reikvam DH, Aleman S, Berhe N, Weis N, Desalegn H, Stenstad T, Heggelund L, Samuelsen E, Karlsen LN, Lindahl K, Pettersen FO, Iversen J, Kleppa E, Bollerup S, Winckelmann AA, Brugger-Synnes P, Simonsen HE, Svendsen J, Kran AB, Holmberg M, Olsen IC, Rueegg CS, Dalgard O (2024)
Clinical trial: An open-label, randomised trial of different re-start strategies after treatment withdrawal in HBeAg negative chronic hepatitis B
Aliment Pharmacol Ther, 60 (4), 434-445
DOI 10.1111/apt.18147, PubMed 38970293

Kazemi AA, Olsen IC (2024)
Instrumental variable analysis with categorical treatment
Stat Methods Med Res, 33 (11-12), 2043-2061
DOI 10.1177/09622802241281960, PubMed 39474719

Kjørholt KE, Sundlisæter NP, Aga AB, Sexton J, Olsen IC, Fremstad H, Spada C, Madland TM, Høili CA, Bakland G, Lexberg Å, Hansen IJW, Hansen IM, Haukeland H, Ljoså MA, Moholt E, Uhlig T, Kvien TK, Solomon DH, van der Heijde D, Haavardsholm EA, Lillegraven S (2024)
Effects of tapering conventional synthetic disease-modifying antirheumatic drugs to drug-free remission versus stable treatment in rheumatoid arthritis (ARCTIC REWIND): 3-year results from an open-label, randomised controlled, non-inferiority trial
Lancet Rheumatol, 6 (5), e268-e278
DOI 10.1016/S2665-9913(24)00021-3, PubMed 38583450

Midgard H, Malme KB, Pihl CM, Berg-Pedersen RM, Tanum L, Klundby I, Haug A, Tveter I, Bjørnestad R, Olsen IC, Finbråten AK, Dalgard O (2024)
Opportunistic Treatment of Hepatitis C Infection Among Hospitalized People Who Inject Drugs (OPPORTUNI-C): A Stepped Wedge Cluster Randomized Trial
Clin Infect Dis, 78 (3), 582-590
DOI 10.1093/cid/ciad711, PubMed 37992203

Patrick-Brown TDJH, Barratt-Due A, Trøseid M, Dyrhol-Riise AM, Nezvalova-Henriksen K, Kåsine T, Aukrust P, Olsen IC, NOR Solidarity consortium (2024)
The effects of remdesivir on long-term symptoms in patients hospitalised for COVID-19: a pre-specified exploratory analysis
Commun Med (Lond), 4 (1), 231
DOI 10.1038/s43856-024-00650-4, PubMed 39533001

Patrick-Brown TDJH, Bourner J, Kali S, Trøseid M, Yazdanpanah Y, Olliaro P, Olsen IC (2024)
Experiences and challenges with the new European Clinical Trials Regulation
Trials, 25 (1), 3
DOI 10.1186/s13063-023-07869-x, PubMed 38167484

Publications 2023

Amstutz A, Speich B, Mentré F, Rueegg CS, Belhadi D, Assoumou L, Burdet C, Murthy S, Dodd LE, Wang Y, Tikkinen KAO, Ader F, Hites M, Bouscambert M, Trabaud MA, Fralick M, Lee TC, Pinto R, Barratt-Due A, Lund-Johansen F, Müller F, Nevalainen OPO, Cao B, Bonnett T, Griessbach A et al. (2023)
Effects of remdesivir in patients hospitalised with COVID-19: a systematic review and individual patient data meta-analysis of randomised controlled trials
Lancet Respir Med, 11 (5), 453-464
DOI 10.1016/S2213-2600(22)00528-8, PubMed 36828006

Heggebø LC, Borgen IMH, Rylander H, Kiserud C, Nordenmark TH, Hellebust TP, Evensen ME, Gustavsson M, Ramberg C, Sprauten M, Magelssen H, Blakstad H, Moorthy J, Andersson K, Raunert I, Henry T, Moe C, Granlund C, Goplen D, Brekke J, Johannessen TA, Solheim TS, Marienhagen K, Humberset Ø, Bergström P et al. (2023)
Investigating survival, quality of life and cognition in PROton versus photon therapy for IDH-mutated diffuse grade 2 and 3 GLIOmas (PRO-GLIO): a randomised controlled trial in Norway and Sweden
BMJ Open, 13 (3), e070071
DOI 10.1136/bmjopen-2022-070071, PubMed 36940951

Lillegraven S, Paulshus Sundlisæter N, Aga AB, Sexton J, Olsen IC, Lexberg ÅS, Madland TM, Fremstad H, Høili CA, Bakland G, Spada C, Haukeland H, Hansen IM, Moholt E, Uhlig T, Solomon DH, van der Heijde D, Kvien TK, Haavardsholm EA (2023)
Effect of tapered versus stable treatment with tumour necrosis factor inhibitors on disease flares in patients with rheumatoid arthritis in remission: a randomised, open label, non-inferiority trial
Ann Rheum Dis, 82 (11), 1394-1403
DOI 10.1136/ard-2023-224476, PubMed 37607809

Telford E, Grinsztejn B, Olsen IC, Pulik N, Mentré F, Haviari S, Hentzien M, Ségéral O, Ekkelenkamp MB, Ogoina D, Strub-Wourgaft N, Diallo A, Yazdanpanah Y, Calmy A (2023)
The international Unity study for antivirals against mpox is a blueprint for future epidemics
Nat Med, 29 (8), 1894-1895
DOI 10.1038/s41591-023-02393-6, PubMed 37391664

Terzić V, Levoyer L, Figarella M, Bigagli E, Mercier N, De Gastines L, Gibowski S, Trøseid M, Demotes J, Olsen IC, Hites M, Ader F, Lopez JRA, Mentré F, Espérou H, Costagliola D, Røttingen JA, Poissy J, Rozé JC, Warris A, O'Leary J, Fernandes RM, Assoumou L, Hankard R, Turner MA et al. (2023)
Implementation of a centralized pharmacovigilance system in academic pan-European clinical trials: Experience from EU-Response and conect4children consortia
Br J Clin Pharmacol, 89 (4), 1318-1328
DOI 10.1111/bcp.15669, PubMed 36680782

Trøseid M, Arribas JR, Assoumou L, Holten AR, Poissy J, Terzić V, Mazzaferri F, Baño JR, Eustace J, Hites M, Joannidis M, Paiva JA, Reuter J, Püntmann I, Patrick-Brown TDJH, Westerheim E, Nezvalova-Henriksen K, Beniguel L, Dahl TB, Bouscambert M, Halanova M, Péterfi Z, Tsiodras S, Rezek M, Briel M et al. (2023)
Efficacy and safety of baricitinib in hospitalized adults with severe or critical COVID-19 (Bari-SolidAct): a randomised, double-blind, placebo-controlled phase 3 trial
Crit Care, 27 (1), 9
DOI 10.1186/s13054-022-04205-8, PubMed 36627655

Østergaard M, van Vollenhoven RF, Rudin A, Hetland ML, Heiberg MS, Nordström DC, Nurmohamed MT, Gudbjornsson B, Ørnbjerg LM, Bøyesen P, Lend K, Hørslev-Petersen K, Uhlig T, Sokka T, Grondal G, Krabbe S, Lindqvist J, Gjertsson I, Glinatsi D, Kapetanovic MC, Aga AB, Faustini F, Parmanne P, Lorenzen T, Giovanni C et al. (2023)
Certolizumab pegol, abatacept, tocilizumab or active conventional treatment in early rheumatoid arthritis: 48-week clinical and radiographic results of the investigator-initiated randomised controlled NORD-STAR trial
Ann Rheum Dis, 82 (10), 1286-1295
DOI 10.1136/ard-2023-224116, PubMed 37423647

Publications 2022

Brun MK, Goll GL, Jørgensen KK, Sexton J, Gehin JE, Sandanger Ø, Olsen IC, Klaasen RA, Warren DJ, Mørk C, Kvien TK, Jahnsen J, Bolstad N, Haavardsholm EA, Syversen SW (2022)
Risk factors for anti-drug antibody formation to infliximab: Secondary analyses of a randomised controlled trial
J Intern Med, 292 (3), 477-491
DOI 10.1111/joim.13495, PubMed 35411981

Skjerven HO, Lie A, Vettukattil R, Rehbinder EM, LeBlanc M, Asarnoj A, Carlsen KH, Despriee ÅW, Färdig M, Gerdin SW, Granum B, Gudmundsdóttir HK, Haugen G, Hedlin G, Håland G, Jonassen CM, Landrø L, Mägi CO, Olsen IC, Rudi K, Saunders CM, Skram MK, Staff AC, Söderhäll C, Tedner SG et al. (2022)
Early food intervention and skin emollients to prevent food allergy in young children (PreventADALL): a factorial, multicentre, cluster-randomised trial
Lancet, 399 (10344), 2398-2411
DOI 10.1016/S0140-6736(22)00687-0, PubMed 35753340

Trøseid M, Hentzien M, Ader F, Cardoso SW, Arribas JR, Molina JM, Mueller N, Hites M, Bonnet F, Manuel O, Costagliola D, Grinsztejn B, Olsen IC, Yazdapanah Y, Calmy A, EU RESPONSE, COMBINE (2022)
Immunocompromised patients have been neglected in COVID-19 trials: a call for action
Clin Microbiol Infect, 28 (9), 1182-1183
DOI 10.1016/j.cmi.2022.05.005, PubMed 35623577

Vestad B, Ueland T, Lerum TV, Dahl TB, Holm K, Barratt-Due A, Kåsine T, Dyrhol-Riise AM, Stiksrud B, Tonby K, Hoel H, Olsen IC, Henriksen KN, Tveita A, Manotheepan R, Haugli M, Eiken R, Berg Å, Halvorsen B, Lekva T, Ranheim T, Michelsen AE, Kildal AB, Johannessen A, Thoresen L et al. (2022)
Respiratory dysfunction three months after severe COVID-19 is associated with gut microbiota alterations
J Intern Med, 291 (6), 801-812
DOI 10.1111/joim.13458, PubMed 35212063

Publications 2021

Barratt-Due A, Olsen IC, Nezvalova-Henriksen K, Kåsine T, Lund-Johansen F, Hoel H, Holten AR, Tveita A, Mathiessen A, Haugli M, Eiken R, Kildal AB, Berg Å, Johannessen A, Heggelund L, Dahl TB, Skåra KH, Mielnik P, Le LAK, Thoresen L, Ernst G, Hoff DAL, Skudal H, Kittang BR, Olsen RB et al. (2021)
Evaluation of the Effects of Remdesivir and Hydroxychloroquine on Viral Clearance in COVID-19 : A Randomized Trial
Ann Intern Med, 174 (9), 1261-1269
DOI 10.7326/M21-0653, PubMed 34251903

EU-Response investigators group, Diallo A, Trøseid M, Simensen VC, Boston A, Demotes J, Olsen IC, Chung F, Paiva JA, Hites M, Ader F, Arribas JR, Baratt-Due A, Melien Ø, Tacconelli E, Staub T, Greil R, Tsiodras S, Briel M, Esperou H, Mentré F, Eustace J, Saillard J, Delmas C, LeMestre S et al. (2021)
Accelerating clinical trial implementation in the context of the COVID-19 pandemic: challenges, lessons learned and recommendations from DisCoVeRy and the EU-SolidAct EU response group
Clin Microbiol Infect, 28 (1), 1-5
DOI 10.1016/j.cmi.2021.10.011, PubMed 34763056

Jenum S, Tonby K, Rueegg CS, Rühwald M, Kristiansen MP, Bang P, Olsen IC, Sellæg K, Røstad K, Mustafa T, Taskén K, Kvale D, Mortensen R, Dyrhol-Riise AM (2021)
A Phase I/II randomized trial of H56:IC31 vaccination and adjunctive cyclooxygenase-2-inhibitor treatment in tuberculosis patients
Nat Commun, 12 (1), 6774
DOI 10.1038/s41467-021-27029-6, PubMed 34811370

Kåsine T, Dyrhol-Riise AM, Barratt-Due A, Kildal AB, Olsen IC, Nezvalova-Henriksen K, Lund-Johansen F, Hoel H, Holten AR, Tveita A, Mathiessen A, Haugli M, Eiken R, Berg Å, Johannessen A, Heggelund L, Dahl TB, Halvorsen B, Mielnik P, Le LAK, Thoresen L, Ernst G, Hoff DAL, Skudal H, Kittang BR et al. (2021)
Neutrophil count predicts clinical outcome in hospitalized COVID-19 patients: Results from the NOR-Solidarity trial
J Intern Med, 291 (2), 241-243
DOI 10.1111/joim.13377, PubMed 34411368

Lerum TV, Maltzahn NN, Aukrust P, Trøseid M, Henriksen KN, Kåsine T, Dyrhol-Riise AM, Stiksrud B, Haugli M, Blomberg B, Kittang BR, Johannessen A, Hannula R, Aballi S, Kildal AB, Eiken R, Dahl TB, Lund-Johansen F, Müller F, Rodriguez JR, Meltzer C, Einvik G, Ueland T, Olsen IC, NOR-SOLIDARITY Consortium et al. (2021)
Persistent pulmonary pathology after COVID-19 is associated with high viral load, weak antibody response, and high levels of matrix metalloproteinase-9
Sci Rep, 11 (1), 23205
DOI 10.1038/s41598-021-02547-x, PubMed 34853380

Lillegraven S, Paulshus Sundlisæter N, Aga AB, Sexton J, Olsen IC, Fremstad H, Spada C, Madland TM, Høili CA, Bakland G, Lexberg Å, Hansen IJW, Hansen IM, Haukeland H, Ljoså MA, Moholt E, Uhlig T, Solomon DH, van der Heijde D, Kvien TK, Haavardsholm EA (2021)
Effect of Half-Dose vs Stable-Dose Conventional Synthetic Disease-Modifying Antirheumatic Drugs on Disease Flares in Patients With Rheumatoid Arthritis in Remission: The ARCTIC REWIND Randomized Clinical Trial
JAMA, 325 (17), 1755-1764
DOI 10.1001/jama.2021.4542, PubMed 33944875

Paulshus Sundlisater N, Aga AB, Olsen IC, Hammer HB, Uhlig T, van der Heijde D, Kvien TK, Haavardsholm EA, Lillegraven S (2021)
Joint tenderness and ultrasound inflammation in DMARD-naïve patients with early rheumatoid arthritis
Ann Rheum Dis, 80 (11), 1493-1494
DOI 10.1136/annrheumdis-2021-220265, PubMed 34083205

Syversen SW, Goll GL, Jørgensen KK, Sandanger Ø, Sexton J, Olsen IC, Gehin JE, Warren DJ, Brun MK, Klaasen RA, Karlsen LN, Noraberg G, Zettel C, Ljoså MKA, Haugen AJ, Njålla RJ, Bruun TJ, Seeberg KA, Michelsen B, Strand EK, Skorpe S, Blomgren IM, Bragnes YH, Dotterud CK, Thune T et al. (2021)
Effect of Therapeutic Drug Monitoring vs Standard Therapy During Infliximab Induction on Disease Remission in Patients With Chronic Immune-Mediated Inflammatory Diseases: A Randomized Clinical Trial
JAMA, 325 (17), 1744-1754
DOI 10.1001/jama.2021.4172, PubMed 33944876

Syversen SW, Jørgensen KK, Goll GL, Brun MK, Sandanger Ø, Bjørlykke KH, Sexton J, Olsen IC, Gehin JE, Warren DJ, Klaasen RA, Noraberg G, Bruun TJ, Dotterud CK, Ljoså MKA, Haugen AJ, Njålla RJ, Zettel C, Ystrøm CM, Bragnes YH, Skorpe S, Thune T, Seeberg KA, Michelsen B, Blomgren IM et al. (2021)
Effect of Therapeutic Drug Monitoring vs Standard Therapy During Maintenance Infliximab Therapy on Disease Control in Patients With Immune-Mediated Inflammatory Diseases: A Randomized Clinical Trial
JAMA, 326 (23), 2375-2384
DOI 10.1001/jama.2021.21316, PubMed 34932077

Publications 2020

Hetland ML, Haavardsholm EA, Rudin A, Nordström D, Nurmohamed M, Gudbjornsson B, Lampa J, Hørslev-Petersen K, Uhlig T, Grondal G, Østergaard M, Heiberg MS, Twisk J, Lend K, Krabbe S, Hyldstrup LH, Lindqvist J, Hultgård Ekwall AK, Grøn KL, Kapetanovic M, Faustini F, Tuompo R, Lorenzen T, Cagnotto G, Baecklund E et al. (2020)
Active conventional treatment and three different biological treatments in early rheumatoid arthritis: phase IV investigator initiated, randomised, observer blinded clinical trial
BMJ, 371, m4328
DOI 10.1136/bmj.m4328, PubMed 33268527

Jørgensen KK, Goll GL, Sexton J, Bolstad N, Olsen IC, Asak Ø, Berset IP, Blomgren IM, Dvergsnes K, Florholmen J, Frigstad SO, Henriksen M, Hagfors J, Huppertz-Hauss G, Haavardsholm EA, Klaasen RA, Moum B, Noraberg G, Prestegård U, Rydning JH, Sagatun L, Seeberg KA, Torp R, Vold C, Warren DJ et al. (2020)
Efficacy and Safety of CT-P13 in Inflammatory Bowel Disease after Switching from Originator Infliximab: Exploratory Analyses from the NOR-SWITCH Main and Extension Trials
BioDrugs, 34 (5), 681-694
DOI 10.1007/s40259-020-00438-7, PubMed 32965617

Lyngbakken MN, Berdal JE, Eskesen A, Kvale D, Olsen IC, Rangberg A, Jonassen CM, Omland T, Røsjø H, Dalgard O (2020)
Norwegian Coronavirus Disease 2019 (NO COVID-19) Pragmatic Open label Study to assess early use of hydroxychloroquine sulphate in moderately severe hospitalised patients with coronavirus disease 2019: A structured summary of a study protocol for a randomised controlled trial
Trials, 21 (1), 485
DOI 10.1186/s13063-020-04420-0, PubMed 32503662

Lyngbakken MN, Berdal JE, Eskesen A, Kvale D, Olsen IC, Rueegg CS, Rangberg A, Jonassen CM, Omland T, Røsjø H, Dalgard O (2020)
A pragmatic randomized controlled trial reports lack of efficacy of hydroxychloroquine on coronavirus disease 2019 viral kinetics
Nat Commun, 11 (1), 5284
DOI 10.1038/s41467-020-19056-6, PubMed 33082342

Skjerven HO, Rehbinder EM, Vettukattil R, LeBlanc M, Granum B, Haugen G, Hedlin G, Landrø L, Marsland BJ, Rudi K, Sjøborg KD, Söderhäll C, Staff AC, Carlsen KH, Asarnoj A, Bains KES, Carlsen OCL, Endre KMA, Granlund PA, Hermansen JU, Gudmundsdóttir HK, Hilde K, Håland G, Kreyberg I, Olsen IC et al. (2020)
Skin emollient and early complementary feeding to prevent infant atopic dermatitis (PreventADALL): a factorial, multicentre, cluster-randomised trial
Lancet, 395 (10228), 951-961
DOI 10.1016/S0140-6736(19)32983-6, PubMed 32087121

Syversen SW, Goll GL, Jørgensen KK, Olsen IC, Sandanger Ø, Gehin JE, Warren DJ, Sexton J, Mørk C, Jahnsen J, Kvien TK, Bolstad N, Haavardsholm EA (2020)
Therapeutic drug monitoring of infliximab compared to standard clinical treatment with infliximab: study protocol for a randomised, controlled, open, parallel-group, phase IV study (the NOR-DRUM study)
Trials, 21 (1), 13
DOI 10.1186/s13063-019-3734-4, PubMed 31907007

Publications 2019

Bernitz S, Dalbye R, Olsen IC, Blix E, Øian P, Eggebø TM (2019)
Zhang's guidelines vs WHO guidelines for diagnosing labour dystocia - Authors' reply
Lancet, 394 (10198), e11
DOI 10.1016/S0140-6736(19)31110-9, PubMed 31253363

Dalbye R, Bernitz S, Olsen IC, Zhang J, Eggebø TM, Rozsa D, Frøslie KF, Øian P, Blix E (2019)
The Labor Progression Study: The use of oxytocin augmentation during labor following Zhang's guideline and the WHO partograph in a cluster randomized trial
Acta Obstet Gynecol Scand, 98 (9), 1187-1194
DOI 10.1111/aogs.13629, PubMed 31017306

Dalbye R, Blix E, Frøslie KF, Zhang J, Eggebø TM, Olsen IC, Rozsa D, Øian P, Bernitz S (2019)
The Labour Progression Study (LaPS): Duration of labour following Zhang's guideline and the WHO partograph - A cluster randomised trial
Midwifery, 81, 102578
DOI 10.1016/j.midw.2019.102578, PubMed 31783231

Olsen IC (2019)
Comment on: Assessments of the unmet need in the management of patients with rheumatoid arthritis: analyses from the NOR-DMARD registry: reply
Rheumatology (Oxford), 58 (10), 1885-1886
DOI 10.1093/rheumatology/kez211, PubMed 31170288

Olsen IC, Lie E, Vasilescu R, Wallenstein G, Strengholt S, Kvien TK (2019)
Assessments of the unmet need in the management of patients with rheumatoid arthritis: analyses from the NOR-DMARD registry
Rheumatology (Oxford), 58 (3), 481-491
DOI 10.1093/rheumatology/key338, PubMed 30508189

Publications 2018

Bernitz S, Dalbye R, Zhang J, Eggebø TM, Frøslie KF, Olsen IC, Blix E, Øian P (2018)
The frequency of intrapartum caesarean section use with the WHO partograph versus Zhang's guideline in the Labour Progression Study (LaPS): a multicentre, cluster-randomised controlled trial
Lancet, 393 (10169), 340-348
DOI 10.1016/S0140-6736(18)31991-3, PubMed 30581039

Ikdahl E, Rollefstad S, Wibetoe G, Salberg A, Krøll F, Bergsmark K, Kvien TK, Olsen IC, Soldal DM, Bakland G, Lexberg Å, Gjesdal CG, Gulseth C, Haugeberg G, Semb AG (2018)
Feasibility of cardiovascular disease risk assessments in rheumatology outpatient clinics: experiences from the nationwide NOCAR project
RMD Open, 4 (2), e000737
DOI 10.1136/rmdopen-2018-000737, PubMed 30305931

Ikdahl E, Wibetoe G, Rollefstad S, Salberg A, Bergsmark K, Kvien TK, Olsen IC, Soldal DM, Bakland G, Lexberg Å, Fevang BTS, Gulseth HC, Haugeberg G, Semb AG (2018)
Guideline recommended treatment to targets of cardiovascular risk is inadequate in patients with inflammatory joint diseases
Int J Cardiol, 274, 311-318
DOI 10.1016/j.ijcard.2018.06.111, PubMed 30007486

Nordberg LB, Lillegraven S, Aga AB, Sexton J, Lie E, Hammer HB, Olsen IC, Uhlig T, van der Heijde D, Kvien TK, Haavardsholm EA (2018)
The Impact of Ultrasound on the Use and Efficacy of Intraarticular Glucocorticoid Injections in Early Rheumatoid Arthritis: Secondary Analyses From a Randomized Trial Examining the Benefit of Ultrasound in a Clinical Tight Control Regimen
Arthritis Rheumatol, 70 (8), 1192-1199
DOI 10.1002/art.40494, PubMed 29575737

Nordberg LB, Lillegraven S, Aga AB, Sexton J, Olsen IC, Lie E, Berner Hammer H, Uhlig T, van der Heijde D, Kvien TK, Haavardsholm EA (2018)
Comparing the disease course of patients with seronegative and seropositive rheumatoid arthritis fulfilling the 2010 ACR/EULAR classification criteria in a treat-to-target setting: 2-year data from the ARCTIC trial
RMD Open, 4 (2), e000752
DOI 10.1136/rmdopen-2018-000752, PubMed 30564452

Norvang V, Sexton J, Kristianslund EK, Olsen IC, Uhlig T, Bakland G, Krøll F, Rødevand E, Wierød A, Kvien TK, Smolen JS, Aletaha D, Haavardsholm EA (2018)
Predicting achievement of the treatment targets at 6 months from 3-month response levels in rheumatoid arthritis: data from real-life follow-up in the NOR-DMARD study
RMD Open, 4 (2), e000773
DOI 10.1136/rmdopen-2018-000773, PubMed 30488000

Paulshus Sundlisæter N, Aga AB, Olsen IC, Hammer HB, Uhlig T, van der Heijde D, Kvien TK, Lillegraven S, Haavardsholm EA, ARCTIC study group (2018)
Clinical and ultrasound remission after 6 months of treat-to-target therapy in early rheumatoid arthritis: associations to future good radiographic and physical outcomes
Ann Rheum Dis, 77 (10), 1421-1425
DOI 10.1136/annrheumdis-2017-212830, PubMed 29934373

Paulshus Sundlisæter N, Olsen IC, Aga AB, Hammer HB, Uhlig T, van der Heijde D, Kvien TK, Lillegraven S, Haavardsholm EA, ARCTIC study group (2018)
Predictors of sustained remission in patients with early rheumatoid arthritis treated according to an aggressive treat-to-target protocol
Rheumatology (Oxford), 57 (11), 2022-2031
DOI 10.1093/rheumatology/key202, PubMed 30053199

Vik I, Bollestad M, Grude N, Bærheim A, Damsgaard E, Neumark T, Bjerrum L, Cordoba G, Olsen IC, Lindbæk M (2018)
Ibuprofen versus pivmecillinam for uncomplicated urinary tract infection in women-A double-blind, randomized non-inferiority trial
PLoS Med, 15 (5), e1002569
DOI 10.1371/journal.pmed.1002569, PubMed 29763434

Wibetoe G, Ikdahl E, Rollefstad S, Olsen IC, Bergsmark K, Kvien TK, Salberg A, Soldal DM, Bakland G, Lexberg Å, Fevang BT, Gulseth HC, Haugeberg G, Semb AG (2018)
Discrepancies in risk age and relative risk estimations of cardiovascular disease in patients with inflammatory joint diseases
Int J Cardiol, 252, 201-206
DOI 10.1016/j.ijcard.2017.10.038, PubMed 29249429

Publications 2017

Jonsson MK, Sundlisæter NP, Nordal HH, Hammer HB, Aga AB, Olsen IC, Brokstad KA, van der Heijde D, Kvien TK, Fevang BS, Lillegraven S, Haavardsholm EA (2017)
Calprotectin as a marker of inflammation in patients with early rheumatoid arthritis
Ann Rheum Dis, 76 (12), 2031-2037
DOI 10.1136/annrheumdis-2017-211695, PubMed 28814431

Jørgensen KK, Lundin KE, Olsen IC, Kvien TK, Jahnsen J (2017)
Efficacy of infliximab biosimilars in patients with Crohn's disease - Authors' reply
Lancet, 390 (10111), 2436
DOI 10.1016/S0140-6736(17)32463-7, PubMed 29208304

Jørgensen KK, Olsen IC, Goll GL, Lorentzen M, Bolstad N, Haavardsholm EA, Lundin KEA, Mørk C, Jahnsen J, Kvien TK, NOR-SWITCH study group (2017)
Switching from originator infliximab to biosimilar CT-P13 compared with maintained treatment with originator infliximab (NOR-SWITCH): a 52-week, randomised, double-blind, non-inferiority trial
Lancet, 389 (10086), 2304-2316
DOI 10.1016/S0140-6736(17)30068-5, PubMed 28502609

Lie E, Lindström U, Zverkova-Sandström T, Olsen IC, Forsblad-d'Elia H, Askling J, Kapetanovic MC, Kristensen LE, Jacobsson LTH (2017)
Tumour necrosis factor inhibitor treatment and occurrence of anterior uveitis in ankylosing spondylitis: results from the Swedish biologics register
Ann Rheum Dis, 76 (9), 1515-1521
DOI 10.1136/annrheumdis-2016-210931, PubMed 28254789

Wibetoe G, Ikdahl E, Rollefstad S, Olsen IC, Bergsmark K, Kvien TK, Salberg A, Soldal DM, Bakland G, Lexberg Å, Fevang BT, Gulseth HC, Haugeberg G, Semb AG (2017)
Cardiovascular disease risk profiles in inflammatory joint disease entities
Arthritis Res Ther, 19 (1), 153
DOI 10.1186/s13075-017-1358-1, PubMed 28673314

Publications 2016

Haavardsholm EA, Aga AB, Olsen IC, Lillegraven S, Hammer HB, Uhlig T, Fremstad H, Madland TM, Lexberg ÅS, Haukeland H, Rødevand E, Høili C, Stray H, Noraas A, Hansen IJ, Bakland G, Nordberg LB, van der Heijde D, Kvien TK (2016)
Ultrasound in management of rheumatoid arthritis: ARCTIC randomised controlled strategy trial
BMJ, 354, i4205
DOI 10.1136/bmj.i4205, PubMed 27530741

Ikdahl E, Rollefstad S, Hisdal J, Olsen IC, Pedersen TR, Kvien TK, Semb AG (2016)
Sustained Improvement of Arterial Stiffness and Blood Pressure after Long-Term Rosuvastatin Treatment in Patients with Inflammatory Joint Diseases: Results from the RORA-AS Study
PLoS One, 11 (4), e0153440
DOI 10.1371/journal.pone.0153440, PubMed 27093159

Ikdahl E, Rollefstad S, Wibetoe G, Olsen IC, Berg IJ, Hisdal J, Uhlig T, Haugeberg G, Kvien TK, Provan SA, Semb AG (2016)
Predictive Value of Arterial Stiffness and Subclinical Carotid Atherosclerosis for Cardiovascular Disease in Patients with Rheumatoid Arthritis
J Rheumatol, 43 (9), 1622-30
DOI 10.3899/jrheum.160053, PubMed 27307523

Midtbø H, Gerdts E, Kvien TK, Olsen IC, Lønnebakken MT, Davidsen ES, Rollefstad S, Semb AG (2016)
The association of hypertension with asymptomatic cardiovascular organ damage in rheumatoid arthritis
Blood Press, 25 (5), 298-304
DOI 10.3109/08037051.2016.1172867, PubMed 27123584

Nordberg LB, Lillegraven S, Lie E, Aga AB, Olsen IC, Hammer HB, Uhlig T, Jonsson MK, van der Heijde D, Kvien TK, Haavardsholm EA, and the ARCTIC working group (2016)
Patients with seronegative RA have more inflammatory activity compared with patients with seropositive RA in an inception cohort of DMARD-naïve patients classified according to the 2010 ACR/EULAR criteria
Ann Rheum Dis, 76 (2), 341-345
DOI 10.1136/annrheumdis-2015-208873, PubMed 27094444

Provan SA, Olsen IC, Austad C, Haugeberg G, Kvien TK, Uhlig T (2016)
Calcium supplementation and inflammation increase mortality in rheumatoid arthritis: A 15-year cohort study in 609 patients from the Oslo Rheumatoid Arthritis Register
Semin Arthritis Rheum, 46 (4), 411-417
DOI 10.1016/j.semarthrit.2016.07.011, PubMed 27522465

Uhlig T, Bjørneboe O, Krøll F, Palm Ø, Olsen IC, Grotle M (2016)
Involvement of the multidisciplinary team and outcomes in inpatient rehabilitation among patients with inflammatory rheumatic disease
BMC Musculoskelet Disord, 17, 18
DOI 10.1186/s12891-016-0870-9, PubMed 26762160

Uhlig T, Lie E, Norvang V, Lexberg ÅS, Rødevand E, Krøll F, Kalstad S, Olsen IC, Kvien TK (2016)
Achievement of Remission and Low Disease Activity Definitions in Patients with Rheumatoid Arthritis in Clinical Practice: Results from the NOR-DMARD Study
J Rheumatol, 43 (4), 716-23
DOI 10.3899/jrheum.151132, PubMed 26879358

Publications 2015

Aga AB, Hammer HB, Olsen IC, Uhlig T, Kvien TK, van der Heijde D, Fremstad H, Madland TM, Lexberg ÅS, Haukeland H, Rødevand E, Høili C, Stray H, Bendvold AN, Soldal DM, Bakland G, Lie E, Haavardsholm EA (2015)
First step in the development of an ultrasound joint inflammation score for rheumatoid arthritis using a data-driven approach
Ann Rheum Dis, 75 (8), 1444-51
DOI 10.1136/annrheumdis-2015-207572, PubMed 26085490

Berg IJ, Semb AG, van der Heijde D, Kvien TK, Olsen IC, Dagfinrud H, Provan SA (2015)
CRP and ASDAS are associated with future elevated arterial stiffness, a risk marker of cardiovascular disease, in patients with ankylosing spondylitis: results after 5-year follow-up
Ann Rheum Dis, 74 (8), 1562-6
DOI 10.1136/annrheumdis-2014-206773, PubMed 25795906

Berg IJ, van der Heijde D, Dagfinrud H, Seljeflot I, Olsen IC, Kvien TK, Semb AG, Provan SA (2015)
Disease activity in ankylosing spondylitis and associations to markers of vascular pathology and traditional cardiovascular disease risk factors: a cross-sectional study
J Rheumatol, 42 (4), 645-53
DOI 10.3899/jrheum.141018, PubMed 25641897

Ikdahl E, Hisdal J, Rollefstad S, Olsen IC, Kvien TK, Pedersen TR, Semb AG (2015)
Rosuvastatin improves endothelial function in patients with inflammatory joint diseases, longitudinal associations with atherosclerosis and arteriosclerosis: results from the RORA-AS statin intervention study
Arthritis Res Ther, 17, 279
DOI 10.1186/s13075-015-0795-y, PubMed 26445924

Ikdahl E, Rollefstad S, Olsen IC, Kvien TK, Hansen IJ, Soldal DM, Haugeberg G, Semb AG (2015)
EULAR task force recommendations on annual cardiovascular risk assessment for patients with rheumatoid arthritis: an audit of the success of implementation in a rheumatology outpatient clinic
Biomed Res Int, 2015, 515280
DOI 10.1155/2015/515280, PubMed 25815322

Moe RH, Grotle M, Kjeken I, Olsen IC, Mowinckel P, Haavardsholm EA, Hagen KB, Kvien TK, Uhlig T (2015)
Effectiveness of an Integrated Multidisciplinary Osteoarthritis Outpatient Program versus Outpatient Clinic as Usual: A Randomized Controlled Trial
J Rheumatol, 43 (2), 411-8
DOI 10.3899/jrheum.150157, PubMed 26669917

Tønnessen E, Svendsen IS, Olsen IC, Guttormsen A, Haugen T (2015)
Performance development in adolescent track and field athletes according to age, sex and sport discipline
PLoS One, 10 (6), e0129014
DOI 10.1371/journal.pone.0129014, PubMed 26043192

Publications 2014

Berg IJ, Semb AG, van der Heijde D, Kvien TK, Hisdal J, Olsen IC, Dagfinrud H, Provan SA (2014)
Uveitis is associated with hypertension and atherosclerosis in patients with ankylosing spondylitis: a cross-sectional study
Semin Arthritis Rheum, 44 (3), 309-13
DOI 10.1016/j.semarthrit.2014.05.017, PubMed 24968705

Midtbø H, Gerdts E, Kvien TK, Olsen IC, Hirth A, Davidsen ES, Semb AG (2014)
Disease activity and left ventricular structure in patients with rheumatoid arthritis
Rheumatology (Oxford), 54 (3), 511-9
DOI 10.1093/rheumatology/keu368, PubMed 25224414

Sveaas SH, Berg IJ, Provan SA, Semb AG, Hagen KB, Vøllestad N, Fongen C, Olsen IC, Michelsen A, Ueland T, Aukrust P, Kvien TK, Dagfinrud H (2014)
Efficacy of high intensity exercise on disease activity and cardiovascular risk in active axial spondyloarthritis: a randomized controlled pilot study
PLoS One, 9 (9), e108688
DOI 10.1371/journal.pone.0108688, PubMed 25268365

Publications 2013

Aga AB, Lie E, Uhlig T, Olsen IC, Wierød A, Kalstad S, Rødevand E, Mikkelsen K, Kvien TK, Haavardsholm EA (2013)
Time trends in disease activity, response and remission rates in rheumatoid arthritis during the past decade: results from the NOR-DMARD study 2000-2010
Ann Rheum Dis, 74 (2), 381-8
DOI 10.1136/annrheumdis-2013-204020, PubMed 24285493

Gandjbakhch F, Haavardsholm EA, Conaghan PG, Ejbjerg B, Foltz V, Brown AK, Døhn UM, Lassere M, Freeston JE, Olsen IC, Bøyesen P, Bird P, Fautrel B, Hetland ML, Emery P, Bourgeois P, Hørslev-Petersen K, Kvien TK, McQueen FM, Østergaard M (2013)
Determining a magnetic resonance imaging inflammatory activity acceptable state without subsequent radiographic progression in rheumatoid arthritis: results from a followup MRI study of 254 patients in clinical remission or low disease activity
J Rheumatol, 41 (2), 398-406
DOI 10.3899/jrheum.131088, PubMed 24334647

Maehlen MT, Olsen IC, Andreassen BK, Viken MK, Jiang X, Alfredsson L, Källberg H, Brynedal B, Kurreeman F, Daha N, Toes R, Zhernakova A, Gutierrez-Achury J, de Bakker PI, Martin J, Teruel M, Gonzalez-Gay MA, Rodríguez-Rodríguez L, Balsa A, Uhlig T, Kvien TK, Lie BA (2013)
Genetic risk scores and number of autoantibodies in patients with rheumatoid arthritis
Ann Rheum Dis, 74 (4), 762-8
DOI 10.1136/annrheumdis-2013-204173, PubMed 24336335

Maehlen MT, Provan SA, de Rooy DP, van der Helm-van Mil AH, Krabben A, Saxne T, Lindqvist E, Semb AG, Uhlig T, van der Heijde D, Mero IL, Olsen IC, Kvien TK, Lie BA (2013)
Associations between APOE genotypes and disease susceptibility, joint damage and lipid levels in patients with rheumatoid arthritis
PLoS One, 8 (4), e60970
DOI 10.1371/journal.pone.0060970, PubMed 23613766

Semb AG, Rollefstad S, Provan SA, Kvien TK, Stranden E, Olsen IC, Hisdal J (2013)
Carotid plaque characteristics and disease activity in rheumatoid arthritis
J Rheumatol, 40 (4), 359-68
DOI 10.3899/jrheum.120621, PubMed 23322468

Publications 2012

Torkildsen O, Wergeland S, Bakke S, Beiske AG, Bjerve KS, Hovdal H, Midgard R, Lilleås F, Pedersen T, Bjørnarå B, Dalene F, Kleveland G, Schepel J, Olsen IC, Myhr KM (2012)
ω-3 fatty acid treatment in multiple sclerosis (OFAMS Study): a randomized, double-blind, placebo-controlled trial
Arch Neurol, 69 (8), 1044-51
DOI 10.1001/archneurol.2012.283, PubMed 22507886

Tvete IF, Olsen IC, Fagerland MW, Meland N, Aldrin M, Smerud KT, Holden L (2012)
An approach to combining parallel and cross-over trials with and without run-in periods using individual patient data
Clin Trials, 9 (2), 164-75
DOI 10.1177/1740774511430714, PubMed 22297620

Publications 2011

Haug IJ, Sagmo LB, Zeiss D, Olsen IC, Draget KI, Seternes T (2011)
Bioavailability of EPA and DHA delivered by gelled emulsions and soft gel capsules
Eur. J. Lipid Sci. Technol., 113 (2), 137-145
DOI 10.1002/ejlt.201000450

Publications 2009

Kjekshus JK, Torp-Pedersen C, Gullestad L, Køber L, Edvardsen T, Olsen IC, Sjaastad I, Qvigstad E, Skomedal T, Osnes JB, Levy FO (2009)
Effect of piboserod, a 5-HT4 serotonin receptor antagonist, on left ventricular function in patients with symptomatic heart failure
Eur J Heart Fail, 11 (8), 771-8
DOI 10.1093/eurjhf/hfp087, PubMed 19567409

Sommer OH, Aga O, Cvancarova M, Olsen IC, Selbaek G, Engedal K (2009)
Effect of oxcarbazepine in the treatment of agitation and aggression in severe dementia
Dement Geriatr Cogn Disord, 27 (2), 155-63
DOI 10.1159/000199236, PubMed 19182483

Sorensen PS, Mellgren SI, Svenningsson A, Elovaara I, Frederiksen JL, Beiske AG, Myhr KM, Søgaard LV, Olsen IC, Sandberg-Wollheim M (2009)
NORdic trial of oral Methylprednisolone as add-on therapy to Interferon beta-1a for treatment of relapsing-remitting Multiple Sclerosis (NORMIMS study): a randomised, placebo-controlled trial
Lancet Neurol, 8 (6), 519-29
DOI 10.1016/S1474-4422(09)70085-7, PubMed 19409854