Johannes Blom

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Articles

Journal article: BMJ OPEN GASTROENTEROLOGY. 2025;12(1):e001828
Temporal trends in surgical treatment of inflammatory bowel disease following introduction of biological drugs in Norway and Sweden
Hoegden A; Perrin V; Adami H-O; Kalager M; Jess T; Ye W; Young J; Helsingen LM; Refsum E; Blom J
Article: CLINICAL AND TRANSLATIONAL GASTROENTEROLOGY. 2025;16(1):e00790
Candidate Genetic Loci Modifying the Colorectal Cancer Risk Caused by Lifestyle Risk Factors
Barot S; Vermani L; Blom J; Larsson S; Liljegren A; Lindblom A
Article: BMJ OPEN GASTROENTEROLOGY. 2024;11(1):e001574
Costs of colorectal cancer screening in Sweden: an observational, longitudinal cost description
Johansson N; Nystrand C; Blom J
Article: FAMILIAL CANCER. 2024;23(4):599-605
Complications of colonoscopy surveillance of patients with Lynch syndrome-33 years of follow up
Frank A; Bernstedt SW; Jamizadeh N; Forsberg A; Hedin C; Blom J; Backman A-S
Article: JOURNAL OF MEDICAL SCREENING. 2024;31(1):8-14
Interval cancer after two rounds of a Swedish population-based screening program using gender-specific cut-off levels in fecal immunochemical test
Wilen HR; Blom J
Article: JOURNAL OF MEDICAL SCREENING. 2024;31(1):15-20
Colorectal cancer screening with faecal immunochemical test: Patterns of participation
Heyman H; Blom J; Saraste D
Article: JAMA NETWORK OPEN. 2024;7(2):e240516
Routine Fecal Occult Blood Screening and Colorectal Cancer Mortality in Sweden
Blom J; Saraste D; Toernberg S; Jonsson H
Article: BMJ OPEN GASTROENTEROLOGY. 2023;10(1):e001037
Risk of malignant lymphomas in patients with inflammatory bowel disease: a population-based cohort study
Yu J; Refsum E; Wieszczy P; Helsingen LM; Perrin V; Hogden A; Loberg M; Blom J; Bretthauer M; Adami H-O; Ye W; Kalager M
Journal article: COCHRANE DATABASE OF SYSTEMATIC REVIEWS. 2023;2023(1)
Prognostic models for colorectal cancer incidence and mortality in patients with inflammatory bowel disease
Gantzel R; Wieszczy P; Refsum E; Jess T; Larsen L; Bretthauer M; Vandvik PO; Blom J; Erichsen R; Kalager M; Helsingen L
Article: JOURNAL OF MEDICAL SCREENING. 2022;29(3):156-165
Interval cancers in a population-based screening program for colorectal cancer with gender-specific cut-off levels for fecal immunochemical test
Wilen HR; Saraste D; Blom J
Article: STATISTICAL METHODS IN MEDICAL RESEARCH. 2022;31(8):1538-1548
Estimating and testing the influence of early diagnosis on cancer survival via point effects of diagnoses and treatments
Wang X; Blom J; Ye W; Yin L
Article: LANCET GASTROENTEROLOGY & HEPATOLOGY. 2022;7(6):513-521
Once-only colonoscopy or two rounds of faecal immunochemical testing 2 years apart for colorectal cancer screening (SCREESCO): preliminary report of a randomised controlled trial
Forsberg A; Westerberg M; Metcalfe C; Steele R; Blom J; Engstrand L; Fritzell K; Hellstrom M; Levin L-A; Lowbeer C; Pischel A; Stromberg U; Tornberg S; Wengstrom Y; Ekbom A; Holmberg L; Hultcrantz R
Article: ANNALS OF ONCOLOGY. 2022;33(6):649-656
Inflammatory bowel disease and risk of adenocarcinoma and neuroendocrine tumors in the small bowel
Yu J; Refsum E; Perrin V; Helsingen LM; Wieszczy P; Loberg M; Bretthauer M; Adami HO; Ye W; Blom J; Kalager M
Article: UNITED EUROPEAN GASTROENTEROLOGY JOURNAL. 2022;10(2):212-224
Risk of hepato-pancreato-biliary cancer is increased by primary sclerosing cholangitis in patients with inflammatory bowel disease: A population-based cohort study
Yu J; Refsum E; Helsingen LM; Folseraas T; Ploner A; Wieszczy P; Barua I; Jodal HC; Melum E; Loberg M; Blom J; Bretthauer M; Adami H-O; Kalager M; Ye W
Article: JOURNAL OF MEDICAL SCREENING. 2021;28(4):439-447
Gender-specific cut-off levels in colorectal cancer screening with fecal immunochemical test: A population-based study of colonoscopy findings and costs
Wilen HR; Saraste D; Blom J
Journal article: CANCER RESEARCH. 2021;81(13_Supplement):841
Abstract 841: Risk of hepatobiliary & pancreatic cancer in inflammatory bowel disease
Yu J; Refsum E; Helsingen LM; Folseraas T; Ploner A; Wieszczy P; Barua I; Jodal HC; Melum E; Løberg M; Blom J; Bretthauer M; Adami H-O; Kalager M; Ye W
Article: JOURNAL OF MEDICAL SCREENING. 2019;26(2):92-97
Gender-specific cut-offs in colorectal cancer screening with FIT: Increased compliance and equal positivity rate
Blom J; Lowbeer C; Elfstrom KM; Sventelius M; Ohman D; Saraste D; Tornberg S
Article: SCANDINAVIAN JOURNAL OF GASTROENTEROLOGY. 2019;54(3):303-310
Fecal immunochemical test in cancer screening - colonoscopy outcome in FIT positives and negatives
Wilen HR; Blom J; Hoijer J; Andersson G; Lowbeer C; Hultcrantz R
Article: JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY. 2019;34(1):103-112
Fecal immunochemical test in colorectal cancer screening: Colonoscopy findings by different cut-off levels
Wilen HR; Blom J; Hoijer J; Hultcrantz R
Article: JOURNAL OF MEDICAL SCREENING. 2018;25(3):126-133
Initial participation as a predictor for continuous participation in population-based colorectal cancer screening
Saraste D; Ohman DJ; Sventelius M; Elfstrom KM; Blom J; Tornberg S
Article: JOURNAL OF MEDICAL SCREENING. 2017;24(3):146-152
Interval cancers in a guaiac-based colorectal cancer screening programme: Consequences on sensitivity
Blom J; Tornberg S
Article: JOURNAL OF MEDICAL SCREENING. 2017;24(2):69-74
Screening vs. non-screening detected colorectal cancer: Differences in pre-therapeutic work up and treatment
Saraste D; Martling A; Nilsson PJ; Blom J; Tornberg S; Janson M
Article: JOURNAL OF MEDICAL SCREENING. 2016;23(3):135-140
Complications after colonoscopy and surgery in a population-based colorectal cancer screening programme
Saraste D; Martling A; Nilsson PJ; Blom J; Tornberg S; Hultcrantz R; Janson M
Article: EUROPEAN SURGERY-ACTA CHIRURGICA AUSTRIACA. 2016;48(4):209-214
Clinical and inflammatory response to first ileocolic resection for Crohn's disease An analysis of 117 cases
Wilen HR; Nystrom P-O; Torkvist L; Blom J
Article: JOURNAL OF MEDICAL SCREENING. 2015;22(3):119-126
Participation rates for organized colorectal cancer screening programmes: an international comparison
Klabunde C; Blom J; Bulliard J-L; Garcia M; Hagoel L; Mai V; Patnick J; Rozjabek H; Senore C; Tornberg S
Article: LAKARTIDNINGEN. 2014;111(40):1717-1719
[Surgical course with focus on intercultural competence. Equal outcomes among Swedish and foreign medical students].
Blom J; Barman L; Wirén M; Jansson H; Nordenström J
Article: JOURNAL OF MEDICAL SCREENING. 2014;21(3):144-150
Five-year experience of organized colorectal cancer screening in a Swedish population - increased compliance with age, female gender, and subsequent screening round
Blom J; Inen SK; Hultcrantz R; Tornberg S
Article: COLORECTAL DISEASE. 2014;16(8):626-630
Results of collagen plug occlusion of anal fistula: a multicentre study of 126 patients
Blom J; Husberg-Sellberg B; Lindelius A; Gustafsson U-M; Carlens S; Oppelstrup H; Bragmark M; Yin L; Nystrom P-O
Article: ENDOSCOPY. 2013;45(1):51-59
European guidelines for quality assurance in colorectal cancer screening and diagnosis: Overview and introduction to the full Supplement publication
von Karsa L; Patnick J; Segnan N; Atkin W; Halloran S; Lansdorp-Vogelaar I; Malila N; Minozzi S; Moss S; Quirke P; Steele RJ; Vieth M; Aabakken L; Altenhofen L; Ancelle-Park R; Antoljak N; Anttila A; Armaroli P; Arrossi S; Austoker J; Banzi R; Bellisario C; Blom J; Brenner H; Bretthauer M; Cancela MC; Costamagna G; Cuzick J; Dai M; Daniel J; Dekker E; Delicata N; Ducarroz S; Erfkamp H; Espinas JA; Faivre J; Wood LF; Flugelman A; Frkovic-Grazio S; Geller B; Giordano L; Grazzini G; Green J; Hamashima C; Herrmann C; Hewitson P; Hoff G; Holten I; Jover R; Kaminski MF; Kuipers EJ; Kurtinaitis J; Lambert R; Launoy G; Lee W; Leicester R; Leja M; Lieberman D; Lignini T; Lucas E; Lynge E; Madai S; Marinho J; Zakotnik JM; Minoli G; Monk C; Morais A; Muwonge R; Nadel M; Neamtiu L; Tuser MP; Pignone M; Pox C; Primic-Zakelj M; Psaila J; Rabeneck L; Ransohoff D; Rasmussen M; Regula J; Ren J; Rennert G; Rey J; Riddell RH; Risio M; Rodrigues V; Saito H; Sauvaget C; Scharpantgen A; Schmiegel W; Senore C; Siddiqi M; Sighoko D; Smith R; Smith S; Suchanek S; Suonio E; Tong W; Tornberg S; Van Cutsem E; Vignatelli L; Villain P; Voti L; Watanabe H; Watson J; Winawer S; Young G; Zaksas V; Zappa M; Valori R
Article: TECHNIQUES IN COLOPROCTOLOGY. 2011;15(3):327-330
Endoanal ultrasonography may distinguish Crohn's anal fistulae from cryptoglandular fistulae in patients with Crohn's disease: a cross-sectional study
Blom J; Nystrom PO; Gunnarsson U; Strigard K
Article: LAKARTIDNINGEN. 2009;106(47):3134
[Why do not socioeconomically disadvantaged persons want to participate in preventive health work?].
Blom J
Article: CANCER EPIDEMIOLOGY BIOMARKERS & PREVENTION. 2008;17(5):1163-1168
A 9-year follow-up study of participants and nonparticipants in sigmoidoscopy screening:: Importance of self-selection
Blom J; Yin L; Liden A; Dolk A; Jeppsson B; Pahlman L; Holmberg L; Nyren O
Article: INTERNATIONAL JOURNAL OF CANCER. 2008;122(7):1618-1623
Toward understanding non participation in sigmoidoscopy screening for colorectal cancer
Blom J; Yin L; Liden A; Dolk A; Jeppsson B; Pahlman L; Holmberg L; Nyren O
Article: EJSO. 2004;30(4):362-369
Colorectal cancer screening with flexible sigmoidoscopy-participants' experiences and technical feasibility
Blom J; Lidén A; Nilsson J; Påhlman L; Nyrén O; Holmberg L
Article: EJSO. 2002;28(8):827-831
Compliance and findings in a Swedish population screened for colorectal cancer with sigmoidoscopy
Blom J; Lidén A; Jeppsson B; Holmberg L; Påhlman L
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All other publications

Review: SCANDINAVIAN JOURNAL OF GASTROENTEROLOGY. 2025;60(5):421-429
Temporal trends in characteristics and management of inflammatory bowel disease
Young JC; Helsingen LM; Refsum E; Hoegden A; Perrin V; Loberg M; Gantzel RH; Bretthauer M; Berglund A; Holme O; Jodal HC; Grimstad T; Brackmann SA; Ye W; Adami H-O; Larsen L; Hernan MA; Jess T; Blom J; Kalager M
Conference publication: PHARMACOEPIDEMIOLOGY AND DRUG SAFETY. 2023;32:336
Closing the gap on inflammatory bowel disease treatments and the risk of cancer: An international collaboration combining national registries with medical chart abstraction
Young JC; Helsingen L; Refsum E; Perrin V; Gantzel RH; Erichsen R; Hogden A; Berglund A; Adami H-O; Jess T; Blom J; Hernan MA; Kalager M
Conference publication: CANCER RESEARCH. 2021;81(13)
Risk of hepatobiliary & pancreatic cancer in inflammatory bowel disease
Yu J; Refsum E; Helsingen LM; Folseraas T; Ploner A; Wieszczy P; Barua I; Jodal HC; Melum E; Loberg M; Blom J; Bretthauer M; Adami H-O; Kalager M; Ye W
Review: EUROPEAN JOURNAL OF CANCER. 2014;50(2):434-446
Sorting out measures and definitions of screening participation to improve comparability: The example of colorectal cancer
Bulliard J-L; Garcia M; Blom J; Senore C; Mai V; Klabunde C
Other: BMJ EVIDENCE-BASED MEDICINE. 2010;15(5):155-156
Once-only flexible sigmoidoscopy screening for adults aged 55-64 years old reduces the incidence of colorectal cancer and colorectal cancer deaths.
Blom J
Letter: INFLAMMATORY BOWEL DISEASES. 2010;16(6):907-909
Analysis of 39 Crohn's Disease Risk Loci in Swedish Inflammatory Bowel Disease Patients
Torkvist L; Halfvarson J; Ong RTH; Lordal M; Sjoqvist U; Bresso F; Bjork J; Befrits R; Lofberg R; Blom J; Carlson M; Padyukov L; D'Amato M; Seielstad M; Pettersson S
Review: LAKARTIDNINGEN. 2008;105(38):2564-2567
[Colorectal cancer screening should be evaluated in Swedish studies].
Blom J
Doctoral thesis: 2007
Aspects of participation in sigmoidoscopy screening for colorectal cancer
Blom J

Employments

Principal Researcher, Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, 2024-2027
Principal Researcher, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 2023-2026

Degrees and Education

Docent, Karolinska Institutet, 2018
Doctor Of Philosophy, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, 2007
Licentiate Degree, Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, 2004

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