Ivar Sønbø Kristiansen

• Engebretsen, Ingrid; Gilhus, Nils Erik; Kristiansen, Ivar Sønbø; Sæther, Erik Magnus; Lindberg-Schager, Ingrid & Arneberg, Fredrik [Vis alle 7 forfattere av denne artikkelen] (2024). The epidemiology and societal costs of myasthenia gravis in Norway: A non-interventional study using national registry data. European Journal of Neurology. ISSN 1351-5101. doi: 10.1111/ene.16233.
• Husum, Yngvil Solheim; Bråten, Ragnhild Haugli; Sæther, Erik Magnus; Moe, Morten Carsten; Kristiansen, Ivar Sønbø & Jørstad, Øystein Kalsnes (2023). Intravitreal anti-vascular endothelial growth factor therapy for retinal diseases in Norway from 2011 to 2021: A combined registry and survey study. Acta Ophthalmologica. ISSN 1755-375X. s. 1–11. doi: 10.1111/aos.16598.
• Pedersen, Kine; Kristiansen, Ivar Sønbø; Sy, Stephen; Kim, Jane J. & Burger, Emily Annika (2023). Designing Guidelines for Those Who Do Not Follow Them: The Impact of Adherence Assumptions on Optimal Screening Guidelines. Value in Health. ISSN 1098-3015. doi: 10.1016/j.jval.2023.04.005. Fulltekst i vitenarkiv
• Røssell, Eeva-Liisa; Bo, Anne; Grønborg, Therese Koops; Kristiansen, Ivar Sønbø; Borgquist, Signe & Scherer, Laura D. [Vis alle 7 forfattere av denne artikkelen] (2023). Danish Women Want to Participate in a Hypothetical Breast Cancer Screening with Harms and No Reduction in Mortality: A Cross-Sectional Survey. Medical decision making. ISSN 0272-989X. doi: 10.1177/0272989X231152830.
• Engebretsen, Ingrid; Munkhaugen, John; Bugge, Christoffer; Halvorsen, Sigrun; Ødegaard, Kristina Malene & Støvring, Henrik [Vis alle 7 forfattere av denne artikkelen] (2022). Gaps and discontinuation of statin treatment in Norway: potential for optimizing management of lipid lowering drugs. European Heart Journal Open (EHJ Open). 2(6). doi: 10.1093/ehjopen/oeac070. Fulltekst i vitenarkiv
• Nielsen, Jesper B.; Kristiansen, Ivar Sønbø & Thapa, Subash (2022). Prolongation of disease-free life: When is the benefit sufficient to warrant the effort of taking a preventive medicine? Preventive Medicine. ISSN 0091-7435. 154. doi: 10.1016/j.ypmed.2021.106867.
• Cyr, Pascale Renée; Pedersen, Kine; Iyer, Anita Lakshmi; Bundorf, Kate; Goldhaber-Fiebert, Jeremy & Gyrd-Hansen, Dorte [Vis alle 8 forfattere av denne artikkelen] (2021). Providing more balanced information on the harms and benefits of cervical cancer screening: A randomized survey among US and Norwegian women. Preventive Medicine Reports. ISSN 2211-3355. doi: 10.1016/j.pmedr.2021.101452. Fulltekst i vitenarkiv Vis sammendrag

  We aimed to identify how additional information about benefits and harms of cervical cancer (CC) screening impacted intention to participate in screening, what type of information on harms women preferred receiving, from whom, and whether it differed between two national healthcare settings. We conducted a survey that randomized screen-eligible women in the United States (n = 1084) and Norway (n = 1060) into four groups according to the timing of introducing additional information. We found that additional information did not significantly impact stated intentions-to-participate in screening or follow-up testing in either country; however, the proportion of Norwegian women stating uncertainty about seeking precancer treatment increased from 7.9% to 14.3% (p = 0.012). Women reported strong system-specific preferences for sources of information: Norwegians (59%) preferred it come from a national public health agency while Americans (59%) preferred it come from a specialist care provider. Regression models revealed having a prior Pap-test was the most important predictor of intentions-to-participate in both countries, while having lower income reduced the probabilities of intentions-to-follow-up and seek precancer treatment among U.S. women. These results suggest that additional information on harms is unlikely to reduce participation in CC screening but could increase decision uncertainty to seek treatment. Providing unbiased information would improve on the ethical principle of respect for autonomy and self-determination. However, the clinical impact of additional information on women's understanding of the trade-offs involved with CC screening should be investigated. Future studies should also consider country-specific socioeconomic barriers to screening if communication re-design initiatives aim to improve CC screening participation.

• Bugge, Christoffer; Kaasa, Stein; Sæther, Erik Magnus; Melberg, Hans Olav & Kristiansen, Ivar Sønbø (2021). What are determinants of utilisation of pharmaceutical anticancer treatment during the last year of life in Norway? A retrospective registry study. BMJ Open. ISSN 2044-6055. 11(9), s. 1–7. doi: 10.1136/bmjopen-2021-050564.
• Bugge, Christoffer; Sæther, Erik Magnus & Kristiansen, Ivar Sønbø (2021). Men receive more end-of-life cancer hospital treatment than women: fact or fiction? Acta Oncologica. ISSN 0284-186X. 60(8), s. 984–991. doi: 10.1080/0284186X.2021.1917000.
• Oteiza, Francisco; Løyland, Hanna Isabel; Bugge, Christoffer; Kristiansen, Ivar Sønbø & Støvring, Henrik (2021). Persistence of statin treatment – the impact of analytic method when estimating drug survival. Norsk Epidemiologi. ISSN 0803-2491. 29(1-2), s. 107–115. doi: 10.5324/nje.v29i1-2.4052.
• Bugge, Christoffer; Brustugun, Odd Terje; Sæther, Erik Magnus & Kristiansen, Ivar Sønbø (2021). Phase- and gender-specific, lifetime, and future costs of cancer: A retrospective population-based registry study. Medicine. ISSN 0025-7974. 100(26), s. 1–8. doi: 10.1097/MD.0000000000026523.
• Bugge, Christoffer; Sæther, Erik Magnus; Brustugun, Odd & Kristiansen, Ivar Sønbø (2021). Societal cost of cancer in Norway –Results of taking a broader cost perspective. Health Policy. ISSN 0168-8510. doi: 10.1016/j.healthpol.2021.05.008.
• Lousdal, Mette Lise; Lash, Timothy L.; Flanders, W Dana; Brookhart, M Alan; Kristiansen, Ivar Sønbø & Kalager, Mette [Vis alle 7 forfattere av denne artikkelen] (2020). Negative controls to detect uncontrolled confounding in observational studies of mammographic screening comparing participants and non-participants. International Journal of Epidemiology. ISSN 0300-5771. 49(3), s. 1032–1042. doi: 10.1093/ije/dyaa029.
• Hovland, Ragnar; Bremer, Sara; Frigaard, Christine; Henjum, Solveig; Faksvåg, Per Kristian & Sæther, Erik Magnus [Vis alle 7 forfattere av denne artikkelen] (2019). Effect of a pharmacist-led intervention on adherence among patients with a first-time prescription for a cardiovascular medicine: a randomized controlled trial in Norwegian pharmacies. International Journal of Pharmacy Practice (IJPP). ISSN 0961-7671. doi: 10.1111/ijpp.12598.
• Hylin, Hannah Douglass; Thrane, Helene; Pedersen, Kine; Kristiansen, Ivar Sønbø & Burger, Emily (2019). The healthcare costs of treating human papillomavirus-related cancers in Norway. BMC Cancer. ISSN 1471-2407. 19(1). doi: 10.1186/s12885-019-5596-2. Fulltekst i vitenarkiv
• Kristiansen, Ivar Sønbø; Bråten, Ragnhild Haugli; Jørstad, Øystein Kalsnes; Moe, Morten Carsten & Sæther, Erik Magnus (2019). Intravitreal therapy for retinal diseases in Norway 2011-2015. Acta Ophthalmologica. ISSN 1755-375X. s. 1–7. doi: 10.1111/aos.14262. Fulltekst i vitenarkiv
• Røssell Johansen, Eeva-Liisa; Lousdal, Mette Lise; Vinther Skriver, Mette; Væth, Michael; Kristiansen, Ivar Sønbø & Støvring, Henrik (2019). Predicting Difference in Mean Survival Time from Reported Hazard Ratios for Cancer Patients. Medical decision making. ISSN 0272-989X. 39(3), s. 228–238. doi: 10.1177/0272989X19832879.
• Sengupta, Kaushik; Thygesen, Lau Caspar; Kristiansen, Ivar Sønbø; Bolin, Kristian; Pukkala, Eero & Emneus, Martha [Vis alle 8 forfattere av denne artikkelen] (2019). Utilization of etoricoxib in dental patients in the Nordic countries: a population-based register study. Acta Odontologica Scandinavica. ISSN 0001-6357. 77(8), s. 584–591. doi: 10.1080/00016357.2019.1622037.
• Wisløff, Torbjørn; Mundal, Liv; Retterstøl, Kjetil; Igland, Jannicke & Kristiansen, Ivar Sønbø (2019). Economic evaluation of lipid lowering with PCSK9 inhibitors in patients with familial hypercholesterolemia: Methodological aspects. Atherosclerosis. ISSN 0021-9150. 287, s. 140–146. doi: 10.1016/j.atherosclerosis.2019.06.900. Fulltekst i vitenarkiv
• Edwards, Christina Hansen; Tomba, Gianpaolo Scalia; Kristiansen, Ivar Sønbø; White, Richard Aubrey & De Blasio, Birgitte Freiesleben (2019). Evaluating costs and health consequences of sick leave strategies against pandemic and seasonal influenza in Norway using a dynamic model. BMJ Open. ISSN 2044-6055. 9. doi: 10.1136/bmjopen-2018-027832. Fulltekst i vitenarkiv
• Iyer, Anita Lakshmi; Bundorf, M. Kate; Gyrd-Hansen, Dorte; Goldhaber-Flebert, Jeremy D.; Cyr, Pascale-Renée & Kristiansen, Ivar Sønbø (2019). How does information on the harms and benefits of cervical cancer screening alter the intention to be screened?: a randomized survey of Norwegian women. European Journal of Cancer Prevention. ISSN 0959-8278. 28(2), s. 87–95. doi: 10.1097/CEJ.0000000000000436.
• Inderhaug, Eivind; Schelp, Carl Henrik; Glambek, Inge & Kristiansen, Ivar Sønbø (2018). Cost-effectiveness analysis of five procedures for great saphenous vein reflux in a Norwegian healthcare setting or societal setting. American Journal of Sports Medicine. ISSN 0363-5465. 6(4), s. 826–831. doi: 10.1177/2050312118801709.
• Bugge, Christoffer; Sæther, Erik Magnus; Pahle, Andreas; Halvorsen, Sigrun & Kristiansen, Ivar Sønbø (2018). Diagnosing heart failure with NT-proBNP point-of-care testing: lower costs and better outcomes. A decision analytic study. British Journal of General Practice. ISSN 0960-1643. doi: 10.3399/bjgpopen18X101596.
• Møller, Mette; Lousdal, Mette Lise; Kristiansen, Ivar Sønbø & Støvring, Henrik (2018). Effect of organized mammography screening on breast cancer mortality: A population-based cohort study in Norway. International Journal of Cancer. ISSN 0020-7136. s. 1–10. doi: 10.1002/ijc.31832.
• Stavem, Knut; Augestad, Liv Ariane; Kristiansen, Ivar Sønbø & Rand, Kim (2018). General population norms for the EQ-5D-3 L in Norway: comparison of postal and web surveys. Health and Quality of Life Outcomes. ISSN 1477-7525. 16(204), s. 1–10. doi: 10.1186/s12955-018-1029-1. Fulltekst i vitenarkiv
• Lousdal, Mette Lise; Møller, Mette H.; Kristiansen, Ivar Sønbø; Kalager, Mette; Wisløff, Torbjørn & Støvring, Henrik (2018). The Screening Illustrator: separating the effects of lead-time and overdiagnosis in mammography screening. European Journal of Public Health. ISSN 1101-1262. 28(6), s. 1138–1142. doi: 10.1093/eurpub/cky085.
• Korman, Max; Retterstøl, Kjetil; Kristiansen, Ivar Sønbø & Wisløff, Torbjørn (2018). Are PCSK9 Inhibitors Cost Effective? PharmacoEconomics (Auckland). ISSN 1170-7690. 36(9), s. 1031–1041. doi: 10.1007/s40273-018-0671-0. Fulltekst i vitenarkiv
• Mundal, Liv; Igland, Jannicke; Veierød, Marit Bragelien; Holven, Kirsten Bjørklund; Ose, Leiv & Selmer, Randi [Vis alle 11 forfattere av denne artikkelen] (2018). Impact of age on excess risk of coronary heart disease in patients with familial hypercholesterolaemia. Heart. ISSN 1355-6037. 104, s. 1600–1607. doi: 10.1136/heartjnl-2017-312706. Fulltekst i vitenarkiv
• Pedersen, Kine; Fogelberg, Sara; Thamsborg, Lise H.; Clements, Mark; Nygård, Mari & Kristiansen, Ivar Sønbø [Vis alle 10 forfattere av denne artikkelen] (2018). An overview of cervical cancer epidemiology and prevention in Scandinavia. Acta Obstetricia et Gynecologica Scandinavica. ISSN 0001-6349. 97(7), s. 795–807. doi: 10.1111/aogs.13313. Fulltekst i vitenarkiv
• Pedersen, Kine; Burger, Emily; Nygård, Mari; Kristiansen, Ivar Sønbø & Kim, Jane J. (2018). Adapting cervical cancer screening for women vaccinated against human papillomavirus infections: The value of stratifying guidelines. European Journal of Cancer. ISSN 0959-8049. 91, s. 68–75. doi: 10.1016/j.ejca.2017.12.018. Fulltekst i vitenarkiv
• Lousdal, Mette Lise; Kristiansen, Ivar Sønbø; Møller, Bjørn & Støvring, Henrik (2017). Predicting Mean Survival Time from Reported Median Survival Time for Cancer Patients. Medical decision making. ISSN 0272-989X. 37(4), s. 391–402. doi: 10.1177/0272989X16655341.
• Burger, Emily; Pedersen, Kine; Sy, Stephen; Kristiansen, Ivar Sønbø & Kim, Jane J (2017). Choosing wisely: a model-based analysis evaluating the trade-offs in cancer benefit and diagnostic referrals among alternative HPV testing strategies in Norway. British Journal of Cancer. ISSN 0007-0920. 117(6), s. 783–790. doi: 10.1038/bjc.2017.248. Fulltekst i vitenarkiv
• Andreassen, A Elizabeth S; Jacobsen, Caroline M; De Blasio, Birgitte Freiesleben; White, Richard; Kristiansen, Ivar Sønbø & Elstrøm, Petter (2017). The impact of methicillin-resistant S. aureus on length of stay, readmissions and costs: a register based case-control study of patients hospitalized in Norway. Antimicrobial Resistance and Infection Control. ISSN 2047-2994. 6. doi: 10.1186/s13756-017-0232-x. Fulltekst i vitenarkiv
• Pahle, Andreas; Sørli, Daniel; Kristiansen, Ivar Sønbø; Deraas, Trygve Sigvart & Halvorsen, Peder Andreas (2017). Practice variation in surgical procedures and IUD-insertions among general practitioners in Norway – a longitudinal study. BMC Family Practice. ISSN 1471-2296. 18:7. doi: 10.1186/s12875-017-0581-9. Fulltekst i vitenarkiv
• Pedersen, Kine; Sørbye, Sveinung Wergeland; Kristiansen, Ivar Sønbø & Burger, Emily (2017). Using novel biomarkers to triage young adult women with minor cervical lesions: a cost-effectiveness analysis. BJOG: An International Journal of Obstetrics and Gynaecology. ISSN 1470-0328. 124(3), s. 474–484. doi: 10.1111/1471-0528.14135. Vis sammendrag

  Objective To evaluate the short-term consequences and cost-effectiveness associated with the use of novel biomarkers to triage young adult women with minor cervical cytological lesions. Design Model-based economic evaluation using primary epidemiological data from Norway, supplemented with data from European and American clinical trials. Setting Organised cervical cancer screening in Norway. Population Women aged 25–33 years with minor cervical cytological lesions detected at their primary screening test. Methods We expanded an existing simulation model to compare 12 triage strategies involving alternative biomarkers (i.e. reflex human papillomavirus (HPV) DNA/mRNA testing, genotyping, and dual staining) with the current Norwegian triage guidelines. Main outcome measures The number of high-grade precancers detected and resource use (e.g. monetary costs and colposcopy referrals) for a single screening round (3 years) for each triage strategy. Cost-efficiency, defined as the additional cost per additional precancer detected of each strategy compared with the next most costly strategy. Results Five strategies were identified as cost-efficient, and are projected to increase the precancer detection rate between 18 and 57%, compared with current guidelines; however, the strategies did not uniformly require additional resources. Strategies involving HPV mRNA testing required fewer resources, whereas HPV DNA-based strategies detected >50% more precancers, but were more costly and required twice as many colposcopy referrals compared with the current guidelines. Conclusion Strategies involving biomarkers to triage younger women with minor cervical cytological lesions have the potential to detect additional precancers, yet the optimal strategy depends on the resources available as well as decision-makers' and women's acceptance of additional screening procedures.

• Pedersen, Kine; Burger, Emily; Sy, Stephen; Kristiansen, Ivar Sønbø & Kim, Jane J. (2016). Cost-effective management of women with minor cervical lesions: Revisiting the application of HPV DNA testing. Gynecologic Oncology. ISSN 0090-8258. 143(2), s. 326–333. doi: 10.1016/j.ygyno.2016.08.231. Fulltekst i vitenarkiv Vis sammendrag

  Background Lack of consensus in management guidelines for women with minor cervical lesions, coupled with novel screening approaches, such as human papillomavirus (HPV) genotyping, necessitate revisiting prevention policies. We evaluated the cost-effectiveness and resource trade-offs of alternative triage strategies to inform cervical cancer prevention in Norway. Methods We used a decision-analytic model to compare the lifetime health and economic consequences associated with ten novel candidate approaches to triage women with minor cervical lesions. Candidate strategies varied by: 1) the triage test(s): HPV testing in combination with cytology, HPV testing alone with or without genotyping for HPV-16 and -18, and immediate colposcopy, and 2) the length of time between index and triage testing (i.e., 6, 12 or 18 months). Model outcomes included quality-adjusted life-years (QALYs), lifetime societal costs, and resource use (e.g., colposcopy referrals). Results The current Norwegian guidelines were less effective and more costly than candidate strategies. Given a commonly-cited willingness-to-pay threshold in Norway of $100,000 per QALY gained, the preferred strategy involved HPV genotyping with immediate colposcopy referral for HPV-16 or -18 positive and repeat HPV testing at 12 months for non-HPV-16 or -18 positive ($78,010 per QALY gained). Differences in health benefits among candidate strategies were small, while resource use varied substantially. More effective strategies required a moderate increase in colposcopy referrals (e.g., a 9% increase for the preferred strategy) compared with current levels. Conclusion New applications of HPV testing may improve management of women with minor cervical lesions, yet are accompanied by a trade-off of increased follow-up procedures.

• Lousdal, Mette L; Kristiansen, Ivar Sønbø; Møller, Bjørn & Støvring, Henrik (2016). Effect of organised mammography screening on stage-specific incidence in Norway: Population study. British Journal of Cancer. ISSN 0007-0920. 114(5), s. 590–596. doi: 10.1038/bjc.2016.8.
• Augestad, Liv Ariane; Stavem, Knut; Kristiansen, Ivar Sønbø; Samuelsen, Carl Haakon & Rand-Hendriksen, Kim (2016). Influenced from the start: anchoring bias in time trade-off valuations. Quality of Life Research. ISSN 0962-9343. 25(9), s. 1–13. doi: 10.1007/s11136-016-1266-x.
• Hagen, Gunhild; Wisløff, Torbjørn & Kristiansen, Ivar Sønbø (2016). The predicted lifetime costs and health consequences of calcium and vitamin D supplementation for fracture prevention—the impact of cardiovascular effects. Osteoporosis International. ISSN 0937-941X. 27(6), s. 2089–2098. doi: 10.1007/s00198-016-3495-9.
• Møller, MH; Kristiansen, Ivar Sønbø; Beisland, Christian; Rørvik, Jarle & Støvring, H (2016). Trends in stage-specific incidence of prostate cancer in Norway, 1980–2010: a population-based study. BJU International. ISSN 1464-4096. 118(4), s. 547–555. doi: 10.1111/bju.13364. Vis sammendrag

  OBJECTIVES: To estimate changes in the stage distribution of prostate cancer during the time period where opportunistic PSA-testing was introduced. SUBJECTS AND METHODS: Cancer stage, age and year of diagnosis were obtained for all men over the age of 50 diagnosed with prostate cancer in Norway during the period 1980-2010. Three calendar-time periods (1980-1989, 1990-2000, and 2001-2010) and three age groups (50-65, 66-74, and 75+) were defined. Birth cohorts were categorized into four intervals: <1915, 1916-1925, 1926-1940 and >1941. We used Poisson regressions to conduct both a time period and cohort-based analysis of trends in the incidence of localised, regional and distant cancer for each combination of age groups and calendar-time periods or birth cohorts, respectively. Additionally, we explored the effect of cohorts on the stage-specific incidence graphically with a Poisson regression using 5-year age groups, and by estimating cumulative incidence rates for each birth cohort. RESULTS: The annual incidence of localised cancers among men aged 50-65 and 66-74 rose from 41.4 and 255.2 per 100,000, respectively, before the introduction of PSA-testing to 137.9 and 418.7 in 2001-2010 afterwards, corresponding to 3.3 (CI: 3.1; 3.5) and 1.6 (CI: 1.6; 1.7) fold increases. The incidence of regional cancers increased by a factor seven among men aged <75. The incidence of distant cancers in men aged 75+ decreased by 29% (CI: 25%; 33%). These findings were confirmed in the cohort-based approach. CONCLUSION: Opportunistic PSA-testing substantially increased the incidence of localised and regional prostate cancers among men aged 50-74 years, which was not fully compensated by the 30% decrease in incidence of distant prostate cancers in older men. This article is protected by copyright. All rights reserved.

• Shin, Minkyung; Valcarcel Salamanca, Beatriz; Kristiansen, Ivar Sønbø & Flem, Elmira (2016). Healthcare Costs of Rotavirus and Other Types of Gastroenteritis in Children in Norway. The Pediatric Infectious Disease Journal. ISSN 0891-3668. 35(4), s. e97–e101. doi: 10.1097/INF.0000000000001026. Vis sammendrag

  BACKGROUND: Norway has initiated a publicly funded rotavirus immunization program for all age-eligible children in 2014. We aimed to estimate the healthcare costs of rotavirus gastroenteritis in children younger than 5 years of age. METHODS: We identified all gastroenteritis cases in children younger than 5 years old treated during 2009-2013 through the national claims database for primary care and the national hospital registry. We estimated direct medical costs of rotavirus-associated primary care consultations and hospital encounters (inpatient admission, outpatient visit, and ambulatory care). We performed a range of one-way sensitivity analyses to explore uncertainty in the cost estimates. RESULTS: Prior to vaccine introduction, the mean healthcare cost of rotavirus gastroenteritis in children younger than 5 years of age was &OV0556;4,440,337 million per year. Among rotavirus-associated costs, 92% were hospital costs and the remaining 8% were primary care costs. The mean annual cost of rotavirus-associated hospital encounters was &OV0556;4,083,691, of which 95% were costs of inpatient hospital admissions. The average healthcare cost of medically attended gastroenteritis in children younger than 5 years of age was approximately &OV0556;8 million per year, of which rotavirus-related costs represented 56%. CONCLUSIONS: Healthcare costs of rotavirus gastroenteritis in Norway are substantial. The cost-effectiveness of ongoing rotavirus immunization program should be reassessed.

• Pedersen, Kine; Sørbye, Sveinung Wergeland; Burger, Emily; Lönnberg, Stefan & Kristiansen, Ivar Sønbø (2015). Using decision-analytic modeling to isolate interventions that are feasible, efficient and optimal: an application from the Norwegian Cervical Cancer Screening Program. Value in Health. ISSN 1098-3015. 18(8), s. 1088–1097. doi: 10.1016/j.jval.2015.08.003. Fulltekst i vitenarkiv
• Kvamme, Maria Knoph; Lie, Elisabeth; Uhlig, Till; Moger, Tron Anders; Kvien, Tore Kristian & Kristiansen, Ivar Sønbø (2015). Cost-effectiveness of TNF inhibitors vs synthetic disease-modifying antirheumatic drugs in patients with rheumatoid arthritis: A Markov model study based on two longitudinal observational studies. Rheumatology. ISSN 1462-0324. 54(7), s. 1226–1235. doi: 10.1093/rheumatology/keu460.
• Halvorsen, Peder Andreas; Aasland, Olaf Gjerløw & Kristiansen, Ivar Sønbø (2015). Decisions on statin therapy by patients’ opinions about survival gains: cross sectional survey of general practitioners. BMC Family Practice. ISSN 1471-2296. 16. doi: 10.1186/s12875-015-0288-8. Fulltekst i vitenarkiv
• Pedersen, Kine; Lönnberg, Stefan; Skare, Gry Baadstrand; Sørbye, Sveinung Wergeland; Burger, Emily & Kristiansen, Ivar Sønbø (2015). Kostnader ved Masseundersøkelsen mot livmorhalskreft. Sykepleien Forskning. ISSN 1890-2936. s. 62–71. doi: 10.4220/Sykepleienf.2015.53414. Fulltekst i vitenarkiv
• Burger, Emily; Sy, Stephen; Nygård, Mari; Kristiansen, Ivar Sønbø & Kim, Jane J (2015). Too late to vaccinate? The incremental benefits and cost-effectiveness of a delayed catch-up program using the 4-valent human papillomavirus vaccine in Norway. Journal of Infectious Diseases. ISSN 0022-1899. 211(2), s. 206–215. doi: 10.1093/infdis/jiu413. Vis sammendrag

  Background: Human papillomavirus (HPV) vaccines are ideally administered prior to HPV exposure; therefore catch-up programs for girls past adolescence have not been readily funded. We evaluated the benefits and cost-effectiveness of a delayed, 1-year female catch-up vaccination program in Norway. Methods: We calibrated a dynamic HPV transmission model to Norwegian data and projected the costs and benefits associated with eight HPV-related conditions while varying the upper vaccination age limit to 20, 22, 24 or 26 years. We explored the impact of vaccine protection in women with prior vaccine-targeted HPV infections, vaccine cost, coverage, and natural- and vaccine-induced immunity. Results: The incremental benefits and cost-effectiveness decreased as the upper age limit for catch-up increased. Assuming a vaccine cost of $150/dose, vaccination up to age 20 remained below Norway’s willingness-to-pay threshold (≈$83,000/ quality-adjusted life year gained); extension to age 22 was cost-effective at a lower cost-per-dose ($50-$75). At high levels of vaccine protection in women with prior HPV exposure, vaccinating up to age 26 was cost-effective. Results were stable with lower coverage. Conclusions: HPV vaccination catch-up programs may be warranted five years after routine implementation; however, even at low vaccine cost per dose, the cost-effectiveness of vaccinating beyond age 22 remains uncertain.

• Lousdal, Mette L; Kristiansen, Ivar Sønbø; Møller, Bjørn & Støvring, Henrik (2014). Trends in breast cancer stage distribution before, during and after introduction of a screening programme in Norway. European Journal of Public Health. ISSN 1101-1262. 24(6), s. 1017–1022. doi: 10.1093/eurpub/cku015.
• LUNDQVIST, CHRISTOFER; Beiske, Antonie Giæver; Reiertsen, Ola & Kristiansen, Ivar Sønbø (2014). Real life cost and quality of life associated with continuous intraduodenal levodopa infusion compared with oral treatment in Parkinson patients. Journal of Neurology. ISSN 0340-5354. 261(12), s. 2438–2445. doi: 10.1007/s00415-014-7515-4.
• Bøhmer, Ellen; Kristiansen, Ivar Sønbø; Arnesen, Harald & Halvorsen, Sigrun (2014). Health-related quality of life after myocardial infarction, does choice of method make a difference? Scandinavian Cardiovascular Journal. ISSN 1401-7431. 48(4), s. 216–222. doi: 10.3109/14017431.2014.923581.
• Harmsen, Charlotte G; Kristiansen, Ivar Sønbø; Larsen, Pia Veldt; Nexøe, Jørgen; Støvring, Henrik & Gyrd-Hansen, Dorte [Vis alle 9 forfattere av denne artikkelen] (2014). Communicating risk using absolute risk reduction or prolongation of life formats: Cluster-randomisedtrial in general practice. British Journal of General Practice. ISSN 0960-1643. 64(621), s. e199–e207. doi: 10.3399/bjgp14X677824.
• Burger, Emily; Nygård, Mari; Gyrd-Hansen, Dorte; Moger, Tron Anders & Kristiansen, Ivar Sønbø (2014). Does the primary screening test influence women's anxiety and intention to screen for cervical cancer? A randomized survey of Norwegian women. BMC Public Health. ISSN 1471-2458. 14:360. doi: 10.1186/1471-2458-14-360. Fulltekst i vitenarkiv
• Burger, Emily; Sy, Stephen; Nygård, Mari; Kristiansen, Ivar Sønbø & Kim, Jane J (2014). Prevention of HPV-Related Cancers in Norway: Cost-Effectiveness of Expanding the HPV Vaccination Program to Include Pre-Adolescent Boys. PLOS ONE. ISSN 1932-6203. 9(3). doi: 10.1371/journal.pone.0089974. Fulltekst i vitenarkiv Vis sammendrag

  Background: Increasingly, countries have introduced female vaccination against human papillomavirus (HPV), causally linked to several cancers and genital warts, but few have recommended vaccination of boys. Declining vaccine prices and strong evidence of vaccine impact on reducing HPV-related conditions in both women and men prompt countries to reevaluate whether HPV vaccination of boys is warranted. Methods: A previously-published dynamic model of HPV transmission was empirically calibrated to Norway. Reductions in the incidence of HPV, including both direct and indirect benefits, were applied to a natural history model of cervical cancer, and to incidence-based models for other non-cervical HPV-related diseases. We calculated the health outcomes and costs of the different HPV-related conditions under a gender-neutral vaccination program compared to a female-only program. Results: Vaccine price had a decisive impact on results. For example, assuming 71% coverage, high vaccine efficacy and a reasonable vaccine tender price of $75 per dose, we found vaccinating both girls and boys fell below a commonly cited cost-effectiveness threshold in Norway ($83,000/quality-adjusted life year (QALY) gained) when including vaccine benefit for all HPV-related diseases. However, at the current market price, including boys would not be considered ‘good value for money.’ For settings with a lower cost-effectiveness threshold ($30,000/QALY), it would not be considered cost-effective to expand the current program to include boys, unless the vaccine price was less than $36/dose. Increasing vaccination coverage to 90% among girls was more effective and less costly than the benefits achieved by vaccinating both genders with 71% coverage. Conclusions: At the anticipated tender price, expanding the HPV vaccination program to boys may be cost-effective and may warrant a change in the current female-only vaccination policy in Norway. However, increasing coverage in girls is uniformly more effective and cost-effective than expanding vaccination coverage to boys and should be considered a priority.

• De Blasio, Birgitte Freiesleben; Flem, Elmira; Latipov, Renat; Kuatbaeva, Ajnagul & Kristiansen, Ivar Sønbø (2014). Dynamic Modeling of Cost-effectiveness of Rotavirus Vaccination, Kazakhstan. Emerging Infectious Diseases. ISSN 1080-6040. 20(1), s. 29–37. doi: 10.3201/eid2001.130019. Fulltekst i vitenarkiv
• Støvring, Henrik; Harmsen, CG; Wisløff, Torbjørn; Jarbøl, DE; Nexøe, Jørgen & Nielsen, Jesper Bo [Vis alle 7 forfattere av denne artikkelen] (2013). A competing risk approach for the European Heart SCORE model based on cause-specific and all-cause mortality. European Journal of Preventive Cardiology (EJPC). ISSN 2047-4873. 20(5), s. 827–836. doi: 10.1177/2047487312445425. Vis sammendrag

  Background: The European Heart SCORE model constitutes the basis for national guidelines for primary prevention and treatment of cardiovascular disease (CVD) in several European countries. The model estimates individuals’ 10-year CVD mortality risks from age, sex, smoking status, systolic blood pressure, and total cholesterol level. The SCORE model, however, is not mathematically consistent and does not estimate all-cause mortality. Our aim is to modify the SCORE model to allow consistent estimation of both CVD-specific and all-cause mortality. Methods: Using a competing risk approach, we first re-estimated the cause-specific risk of dying from cardiovascular disease, and secondly we incorporated non-CVD mortality. Finally, non-CVD mortality was allowed to also depend on smoking status, and not only age and sex. From the models, we estimated CVD-specific and all-cause 10-year mortality risk, and the expected residual lifetime together with corresponding expected effects of statin treatment. Results: The modified model provided CVD-specific 10-year mortality risks similar to those of the European Heart SCORE model. Incorporation of non-CVD mortality increased 10-year mortality risks, in particular for older individuals. When non-CVD mortality was assumed unaffected by smoking status, the absolute risk reduction due to statin treatment ranged from 0.0% to 3.5%, whereas the gain in expected residual lifetime ranged from 3 to 11 months. Statin effectiveness increased for non-smokers and declined for smokers, when smoking was allowed to influence non-CVD mortality. Conclusion: The modified model provides mathematically consistent estimates of mortality risk and expected residual lifetime together with expected benefits from statin treatment.

• Augestad, Liv Ariane; Rand-Hendriksen, Kim; Stavem, Knut & Kristiansen, Ivar Sønbø (2013). Time trade-off and attitudes toward euthanasia: implications of using 'death' as an anchor in health state valuation. Quality of Life Research. ISSN 0962-9343. 22(4), s. 705–714. doi: 10.1007/s11136-012-0192-9.
• Wisløff, Torbjørn; Atar, Dan & Kristiansen, Ivar Sønbø (2013). Cost Effectiveness of Drug-Eluting Stents as Compared With Bare Metal Stents in Patients With Coronary Artery Disease. American Journal of Therapeutics. ISSN 1075-2765. 20(6), s. 596–601. doi: 10.1097/MJT.0b013e3182211a01. Vis sammendrag

  The aim of this study was to estimate the incremental cost effectiveness of replacing bare metal stents (BMS) by drug-eluting stents (DES) when using trial data and registry data. We developed a Markov model (model of cost effectiveness of coronary artery disease) in which 60-year-old patients started by undergoing percutaneous coronary intervention for acute or subacute coronary artery disease. The patients are followed until death or 100 years of age. Data on the occurrence of events (revascularization, acute myocardial infarction, and death) were based on Scandinavian registry data. Separate analyses were conducted with data on effectiveness based on randomized controlled trials and patient registries. On using trial data, it was found that sirolimus-eluting stents (SES) yield 0.003 greater life expectancy and $3300 lower costs than do BMS (dominant strategy). Paclitaxel-eluting stents (PES) yield 0.148 more life years than do SES at additional lifetime costs of $2800 ($21,400 per life year gained). On using registry data, the cost per life year gained was found to be $4900 when replacing BMS with DES. Probabilistic sensitivity analyses, on the other hand, indicate that PES only has a 50%-75% probability of being cost effective, regardless of the type of effectiveness data. DESs are cost effective with current willingness to pay for life year gains. Whether PES or SES is the most effective DES remains uncertain.

• Boberg, Kirsten Muri; Wisløff, Torbjørn; Kjøllesdal, Karl Sæbjørn; Støvring, Henrik & Kristiansen, Ivar Sønbø (2013). Cost and health consequences of treatment of primary biliary cirrhosis with ursodeoxycholic acid. Alimentary Pharmacology and Therapeutics. ISSN 0269-2813. 38(7), s. 794–803. doi: 10.1111/apt.12435.
• Harmsen, Charlotte G; Jarbøl, Dorte E; Nexøe, Jørgen; Støvring, Henrik; Gyrd-Hansen, Dorte & Nielsen, Jesper Bo [Vis alle 8 forfattere av denne artikkelen] (2013). Impact of effectiveness information format on patient choice of therapy and satisfaction with decisions about chronic disease medication: the "Influence of intervention Methodologies on Patient Choice of Therapy (IMPACT)" cluster-randomised trial in general practice. BMC Health Services Research. ISSN 1472-6963. 13. doi: 10.1186/1472-6963-13-76.
• Halvorsen, Peder Andreas; Edwards, A.; Aaraas, Ivar Johannes; Aasland, Olaf Gjerløw & Kristiansen, Ivar Sønbø (2013). What professional activities do general practitioners find most meaningful? Cross sectional survey of Norwegian general practitioners. BMC Family Practice. ISSN 1471-2296. 14(41). doi: 10.1186/1471-2296-14-41. Fulltekst i vitenarkiv
• Augestad, Liv Ariane; Rand-Hendriksen, Kim; Kristiansen, Ivar Sønbø & Stavem, Knut (2012). Impact of Transformation of Negative Values and Regression Models on Differences Between the UK and US EQ-5D Time Trade-Off Value Sets. PharmacoEconomics (Auckland). ISSN 1170-7690. 30(12), s. 1203–1214. doi: 10.2165/11595420-000000000-00000. Vis sammendrag

  Background National EQ-5D value sets are developed because preferences for health may vary in different populations. UK values are lower than US values for most of the 243 possible EQ-5D health states. Although similar protocols were used for data collection, analytic choices regarding how to model values from the collected data may also influence national value sets. Participants in the UK and US studies assessed the same subset of 42 EQ-5D health states using the time trade-off (TTO) method. However, different methods were used to transform negative values to a range bounded by 0 and −1, and values for all 243 health states were estimated using two different regression models. The transformation of negative values is inconsistent with expected utility theory, and the choice of which transformation method to use lacks a theoretical foundation. Objectives Our objectives were to assess how much of the observed difference between the UK and US EQ-5D value sets may be explained by the choice of transformation method for negative values relative to the choice of regression model and the differences between elicited TTO values in the respective national studies (datasets). Methods We applied both transformation methods and both regression models to each of the two datasets, resulting in eight comparable value sets. We arranged these value sets in pairs in which one source of difference (transformation method, regression model or dataset) was varied. For each of these paired value sets, we calculated the mean difference between the two matching values for each of the 243 health states. Finally, we calculated the mean utility gain for all possible transitions between pairs of EQ-5D health states within each value set and used the difference in transition scores as a measure of impact from changing transformation method, regression model or dataset. Results The mean absolute difference in values was 1.5 times larger when changing the transformation method than when using different datasets. The choice of transformation method had a 3.2 times larger effect on the mean health gain (transition score) than the choice of dataset. The mean health gain in the UK value set was 0.09 higher than in the US value set. Using the UK transformation method on the US dataset reduced this absolute difference to 0.02. The choice of regression model had little overall impact on the differences between the value sets. Conclusions Most of the observed differences between the UK and US value sets were caused by the use of different transformation methods for negative values, rather than differences between the two study populations as reflected in the datasets. Changing the regression model had little impact on the differences between the value sets.

• Li, J; Ulvin, Kim Andre; Biboh, Henrietta & Kristiansen, Ivar Sønbø (2012). Cost-effectiveness of supplementing a broth-enriched culture test with the Xpert meticillin-resistant Staphylococcus aureus (MRSA) assay for screening inpatients at high risk of MRSA. Journal of Hospital Infection. ISSN 0195-6701. 82(4), s. 227–233. doi: 10.1016/j.jhin.2012.08.009.
• Harmsen, Charlotte G; Støvring, Henrik; Jarbøl, Dorte E; Nexøe, Jørgen; Gyrd-Hansen, Dorte & Nielsen, Jesper Bo [Vis alle 8 forfattere av denne artikkelen] (2012). Medication effectiveness may not be the major reason for accepting cardiovascular preventive medication: A population-based survey. BMC Medical Informatics and Decision Making. ISSN 1472-6947. 12. doi: 10.1186/1472-6947-12-89.
• Kvamme, Maria Knoph; Lie, Elisabeth; Kvien, Tore Kristian & Kristiansen, Ivar Sønbø (2012). Two-year direct and indirect costs for patients with inflammatory rheumatic joint diseases: data from real-life follow-up of patients in the NOR-DMARD registry. Rheumatology. ISSN 1462-0324. 51(9), s. 1618–1627. doi: 10.1093/rheumatology/kes074.
• Xue, Yiting; Kristiansen, Ivar Sønbø & De Blasio, Birgitte Freiesleben (2012). Dynamic modelling of costs and health consequences of school closure during an influenza pandemic. BMC Public Health. ISSN 1471-2458. 12. doi: 10.1186/1471-2458-12-962.
• Fuglenes, Dorthe; Aas, Eline; Botten, Grete Synøve; Øian, Pål & Kristiansen, Ivar Sønbø (2012). Maternal Preference for Cesarean Delivery Do Women Get What They Want? Obstetrics and Gynecology. ISSN 0029-7844. 120(2), s. 252–260. doi: 10.1097/AOG.0b013e3182605b1a.
• Burger, Emily; Ortendahl, J D; Sy, S; Kristiansen, Ivar Sønbø & Kim, J.J. (2012). Cost-effectiveness of cervical cancer screening with primary human papillomavirus testing in Norway. British Journal of Cancer. ISSN 0007-0920. 106(9), s. 1571–1578. doi: 10.1038/bjc.2012.94.
• Wisløff, Torbjørn; Selmer, Randi; Halvorsen, Sigrun; Fretheim, Atle; Norheim, Ole Frithjof & Kristiansen, Ivar Sønbø (2012). Choice of generic antihypertensive drugs for the primary prevention of cardiovascular disease - A cost-effectiveness analysis. BMC Cardiovascular Disorders. ISSN 1471-2261. 12. doi: 10.1186/1471-2261-12-26.
• Rand-Hendriksen, Kim; Augestad, Liv Ariane; Dahl, Fredrik Andreas; Kristiansen, Ivar Sønbø & Stavem, Knut (2012). A Shortcut to Mean-Based Time Tradeoff Tariffs for the EQ-5D? Medical decision making. ISSN 0272-989X. 32(4), s. 569–577. doi: 10.1177/0272989X11431607.
• Augestad, Liv Ariane; Rand-Hendriksen, Kim; Kristiansen, Ivar Sønbø & Stavem, Knut (2012). Learning Effects in Time Trade-Off Based Valuation of EQ-5D Health States. Value in Health. ISSN 1098-3015. 15(2), s. 340–345. doi: 10.1016/j.jval.2011.10.010.
• Fretheim, Atle; Odgaard-Jensen, Jan; Brørs, Odd; Madsen, Steinar; Njølstad, Inger & Norheim, Ole Frithjof [Vis alle 10 forfattere av denne artikkelen] (2012). Comparative effectiveness of antihypertensive medication of primary prevention of cardiovascular disease: Systematic review and multiple treatments meta-analysis. BMC Medicine. ISSN 1741-7015. 10. doi: 10.1186/1741-7015-10-33. Fulltekst i vitenarkiv

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• Østby, Jens Torup & Kristiansen, Ivar Sønbø (2023). Hvordan ta hensyn til helsetjenestens verdiskaping ved prioritering av helsetiltak? Tidsskrift for Den norske legeforening. ISSN 0029-2001. 143(17). doi: 10.4045/tidsskr.23.0706.
• Syse, Aslak & Kristiansen, Ivar Sønbø (2022). Legers rolle i Nye metoder. Tidsskrift for Den norske legeforening. ISSN 0029-2001. 142(1), s. 1–3. doi: 10.4045/tidsskr.21.0823.
• Kvamme, Maria Knoph; Lie, Elisabeth; Uhlig, Till; Moger, Tron Anders; Kvien, Tore Kristian & Kristiansen, Ivar Sønbø (2020). Erratum: Cost-effectiveness of TNF inhibitors vs synthetic disease-modifying antirheumatic drugs in patients with rheumatoid arthritis: A Markov model study based on two longitudinal observational studies (Rheumatology (2015 54 (1226-1235) DOI: 10.1093/rheumatology/keu460). Rheumatology. ISSN 1462-0324. 59(4). doi: 10.1093/rheumatology/kez609.
• Zahl, Per Henrik & Kristiansen, Ivar Sønbø (2020). Re: Stage-specific survival has improved for young breast cancer patients since 2000: but not equally? Breast Cancer Research and Treatment. ISSN 0167-6806. 185(2), s. 527–528. doi: 10.1007/s10549-020-05941-7.
• Kristiansen, Ivar Sønbø; Burger, Emily & De Blasio, Birgitte Freiesleben (2020). Covid-19: Simuleringsmodeller ved epidemier. Tidsskrift for Den norske legeforening. ISSN 0029-2001. 140(6). doi: 10.4045/tidsskr.20.0225.
• Kristiansen, Ivar Sønbø; Burger, Emily & De Blasio, Birgitte Freiesleben (2020). Covid-19: Simuleringsmodeller ved epidemier. Tidsskrift for Den norske legeforening. ISSN 0029-2001. 140(6), s. 1–6. doi: 10.4045/TIDSSKR.20.0225.
• Kristiansen, Ivar Sønbø; Bugge, Christoffer & Førde, Olav Helge (2018). Kristiansen og medarbeidere svarer : . Tidsskrift for Den norske legeforening. ISSN 0029-2001. 138(12), s. 1102–1103. doi: 10.4045/tidsskr.18.0594.
• Kristiansen, Ivar Sønbø; Bugge, Christoffer & Førde, Olav Helge (2018). Bidrar overdiagnostikk til høye melanomtall? Tidsskrift for Den norske legeforening. ISSN 0029-2001. 138(11), s. 1007–1010. doi: 10.4045/tidsskr.17.0600.
• Kristiansen, Ivar Sønbø & Bugge, Christoffer (2018). Prioritering i pasienters siste leveår. Tidsskrift for Den norske legeforening. ISSN 0029-2001. 138(9). doi: 10.4045/tidsskr.18.0389.
• Kristiansen, Ivar Sønbø (2017). Verdiløs helsepolitikk. Tidsskrift for Den norske legeforening. ISSN 0029-2001. 137(16), s. 1156–1157. doi: 10.4045/tidsskr.17.0667.
• Burger, Emily; Pedersen, Kine; Sy, Stephen; Kristiansen, Ivar Sønbø & Kim, Jane J. (2017). Primary HPV-based Cervical Cancer Screening: Balancing Health Benefits Colposcopy Referrals.
• Hagen, Gunhild; Wisløff, Torbjørn & Kristiansen, Ivar Sønbø (2016). Bør Tine rekruttere melkedrikkere? Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116.
• Mundal, Liv; Igland, Jannicke; Veierød, Marit Bragelien; Holven, Kirsten Bjørklund; Selmer, Randi & Wisløff, Torbjørn [Vis alle 8 forfattere av denne artikkelen] (2016). INCIDENCE OF ACUTE MYOCARDIAL INFARCTION IN PATIENTS WITH GENOTYPED FAMILIAL HYPERCHOLESTEROLEMIA IN NORWAY DURING 2001-2009. Circulation. ISSN 0009-7322. 134 (25), s. E711–E711.
• Pedersen, Kine; Burger, Emily; Sy, Stephen; Kristiansen, Ivar Sønbø & Kim, Jane J. (2016). Cost-effective management of women with minor cervical lesions: Revisiting the application of HPV DNA testing.
• Sørbye, Sveinung Wergeland; Kristiansen, Ivar Sønbø; Ursin, Giske; Iversen, Ole-Erik & Aarseth, Hans Petter (2016). Fortsatt strid om etikken bak HPV-prosjekt. [Internett]. Dagens Medisin. Vis sammendrag

  Forskere mener pilotprosjektet burde vært søkt Regional Etisk Komite (REK) på vanlig måte, som for andre kliniske studier. – Det at Kreftregisteret har valgt randomisering betyr at det er tvil om effekten av innføringen. Det er usikkert om HPV-test hvert femte år forebygger mer kreft enn celleprøve hvert tredje år. Dersom man velger å randomisere er det per definisjon en studie, sier Sveinung Wergeland Sørbye, overlege i patologi ved Universitetssykehuset i Nord-Norge.

• Pedersen, Kine; Sørbye, Sveinung Wergeland; Kristiansen, Ivar Sønbø & Burger, Emily (2015). Novel Biomarkers to Triage Women with Minor Cervical Lesions: Quantifying the Cost-Effectiveness Tradeoffs to Ensure Feasible Implementation.
• Pedersen, Kine; Sørbye, Sveinung Wergeland; Burger, Emily; Lönnberg, Stefan & Kristiansen, Ivar Sønbø (2015). Quantifying benefits and harms in cervical cancer screening: A decision analytic approach.
• Edwards, Christina Hansen; Scalia Tomba, Gianpaolo; de Blasio, Birgitte Freiesleben; Kristiansen, Ivar Sønbø & White, Richard Aubrey (2014). ) Dynamic modeling of the cost-effectiveness of sick leave practices during influenza illness.
• Kristiansen, Ivar Sønbø (2014). Re: Hvorfor blir jeg ikke sitert? Tidsskrift for Den norske legeforening. ISSN 0029-2001. 134(16). doi: 10.4045/tidsskr.14.0915.
• Pedersen, Kine; Sørbye, Sveinung Wergeland; Lönnberg, Stefan; Burger, Emily & Kristiansen, Ivar Sønbø (2014). Trade-offs in cervial cancer screening - Balancing detected cancer precursors and resource use. Vis sammendrag

  Reflex HPV-testing allows for improvements in both effectiveness and cost-effectiveness of the current screening algorithm. Candidate strategies can detect a larger number of precancers while using fewer resources compared to current practice; however, the optimal strategy depends on society’s willingness to pay costs and accept harms. Ultimately, the down-stream effectiveness of the alternative algorithms will depend on the extent to which precancers regress or progress into cancer.

• Sørbye, Sveinung Wergeland & Kristiansen, Ivar Sønbø (2014). - En celleprøve er ikke en perfekt test som kan garantere mot utvikling av livmorhals-kreft. Avisa Nordland. ISSN 1503-5964. s. 3–3. Vis sammendrag

  I Norge har vi et organisert masseundersøkelsesprogram mot livmorhalskreft. Kvinner fra 25–69 år anbefales å ta celleprøve hvert tredje år, og omtrent 80 prosent tar prøven. Det har trolig halvert antallet tilfeller av livmorhalskreft. Hvert år får likevel ca. 300 kvinner påvist denne typen kreft. Omtrent 150 av disse kvinnene har tatt celleprøve og omtrent 70 har hatt bare normale celleprøver.

• Sørbye, Sveinung Wergeland; Stålcrantz, Jeanette; Trovik, Jone; Nøkleby, Hanne & Kristiansen, Ivar Sønbø (2014). - Alle kvinner bør ta denne vaksinen. [Internett]. Klikk.no. Vis sammendrag

  Folkehelseinstituttet er ansvarlig for det norske barnevaksinasjonsprogrammet og utgangspunktet deres er at det er viktig at jenter tar HPV-vaksinen før de blir utsatt for smitte slik at de får best mulig effekt av vaksinen. HPV-vaksinen Gardasil er likevel godkjent til bruk hos kvinner opp til 45 år. - At vaksinen bare virker for dem som ikke har vært seksuelt aktive eller har vært smittet er en myte. Det er dokumentert god forebyggende effekt opp til 45 år, sier imidlertid Sveinung Sørbye, overlege ved avdeling for klinisk patologi ved Universitetssykehuset Nord-Norge (UNN), som selv har forelest om vaksinen for andre leger.

• Tveito, Marit & Kristiansen, Ivar Sønbø (2014). Tallenes taler. Tidsskrift for Den norske legeforening. ISSN 0029-2001. 134(3), s. 288–290. doi: 10.4045/tidsskr.13.1638.
• Sørbye, Sveinung Wergeland & Kristiansen, Ivar Sønbø (2014). Forebygging av livmorhalskreft. Avisa Nordland. ISSN 1503-5964. s. 3–3. Vis sammendrag

  Nordlandssykehuset Bodø har blitt omtalt flere ganger i media de siste ukene i forbindelse med at noen kvinner har utviklet kreft i livmorhalsen til tross for at de var undersøkt med celleprøve. Det viste seg i ettertid at flere av prøver som var blitt oppfattet som normale, hadde til dels alvorlige celleforandringer ved fornyet undersøkelse. Saken er politianmeldt og fylkeslegen gransker den. Allmennheten bør vite at celleprøve ikke er en perfekt test som kan garantere mot utvikling av livmorhalskreft.

• Kristiansen, Ivar Sønbø & Sørbye, Sveinung Wergeland (2014). HPV-testing: Usikkerhet og verdivalg. Dagens medisin. ISSN 1501-4290. Vis sammendrag

  Vi støtter forslaget om å prøve ut HPV-testing i Norge, men bare dersom forsøket er REK-godkjent og kvinnene er informert om at de deltar i en eksperimentell studie. Alle involverte må få tallmessig informasjon om HPV-testingens positive og negative konsekvenser.

• Hagen, Gunhild; Rand-Hendriksen, Kim; Bjørnelv, Gudrun Maria Waaler; Kvamme, Maria Knoph & Kristiansen, Ivar Sønbø (2013). Bør prioriteringer QALYfiseres? Dagens medisin. ISSN 1501-4290.
• Olsen, Jan Abel; Kristiansen, Ivar Sønbø; Magnussen, Jon; Norheim, Ole Frithjof & Robberstad, Bjarne (2013). Fagkritikkens utfordringer. Tidsskrift for Den norske legeforening. ISSN 0029-2001. 133(5). doi: 10.4045/tidsskr.13.0174.
• Samuelsen, Carl Haakon; Augestad, Liv Ariane; Stavem, Knut; Kristiansen, Ivar Sønbø & Rand-Hendriksen, Kim (2013). Anchoring effects in the Lead-Time Time Trade-Off.
• Sørbye, Sveinung Wergeland; Halvorsen, Peder Andreas & Kristiansen, Ivar Sønbø (2013). Screening for livmorhalskreft – fastlegenes viktigste screeningoppgave? Utposten. ISSN 0800-5680. 42(2), s. 34–37. Vis sammendrag

  Tidlig på 90-tallet møter ”Eva” til screening for livmorhalskreft. Prøven viser lavgradige celleforandringer. Oppfølging ihht. retningslinjer medfører at ”Eva” de neste 18 årene får utført til sammen 16 nye celleprøver og 7 biopsier. Etter innføring av HPV testing viser celleprøven lavgradige celleforandringer og positiv HPV-test. Biopsi viser nå CIN 2, og ”Eva” blir konisert. Histologisk undersøkelse av resektatet viser invasiv cervixcancer, og ”Eva” blir hysterektomert.

• Wisløff, Torbjørn; Aalen, Odd O. & Kristiansen, Ivar Sønbø (2012). Regarding adequate methods for comparison of effect measures - Reply. Journal of Clinical Epidemiology. ISSN 0895-4356. 65(4), s. 462–463. doi: 10.1016/j.jclinepi.2011.10.005.

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