O Roikjær

1.1k total citations
37 papers, 865 citations indexed

About

O Roikjær is a scholar working on Surgery, Oncology and Pulmonary and Respiratory Medicine. According to data from OpenAlex, O Roikjær has authored 37 papers receiving a total of 865 indexed citations (citations by other indexed papers that have themselves been cited), including 24 papers in Surgery, 20 papers in Oncology and 11 papers in Pulmonary and Respiratory Medicine. Recurrent topics in O Roikjær's work include Colorectal Cancer Surgical Treatments (14 papers), Colorectal Cancer Screening and Detection (9 papers) and Cardiac, Anesthesia and Surgical Outcomes (8 papers). O Roikjær is often cited by papers focused on Colorectal Cancer Surgical Treatments (14 papers), Colorectal Cancer Screening and Detection (9 papers) and Cardiac, Anesthesia and Surgical Outcomes (8 papers). O Roikjær collaborates with scholars based in Denmark, Norway and Belgium. O Roikjær's co-authors include Per Jess, Jakob Lykke, Henrik Kehlet, Torben Callesen, F Burcharth, H Baden, I. Krogh Pedersen, N. H. Jensen, Svend Schulze and Jens Andersen and has published in prestigious journals such as Cancer, British journal of surgery and Anesthesia & Analgesia.

In The Last Decade

O Roikjær

37 papers receiving 835 citations

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name h Career Trend Papers Cites
O Roikjær Denmark 19 564 415 228 122 99 37 865
Bradford J. Kim United States 16 424 0.8× 209 0.5× 211 0.9× 134 1.1× 80 0.8× 52 792
Patrick J. Broe Ireland 17 635 1.1× 164 0.4× 403 1.8× 84 0.7× 39 0.4× 64 912
Etienne Abdelnour‐Berchtold Switzerland 15 718 1.3× 179 0.4× 542 2.4× 364 3.0× 154 1.6× 35 1.2k
Linda W. Martin United States 16 569 1.0× 291 0.7× 591 2.6× 109 0.9× 55 0.6× 73 963
Relin Yang United States 16 246 0.4× 266 0.6× 197 0.9× 77 0.6× 22 0.2× 20 713
W. F. A. Miles United Kingdom 12 750 1.3× 249 0.6× 247 1.1× 397 3.3× 24 0.2× 23 1.0k
J Weerts Belgium 18 2.2k 3.9× 617 1.5× 512 2.2× 40 0.3× 121 1.2× 46 2.4k
J. R. T. Monson United Kingdom 14 601 1.1× 380 0.9× 241 1.1× 117 1.0× 26 0.3× 28 884
B. Rumstadt Germany 15 716 1.3× 514 1.2× 350 1.5× 97 0.8× 51 0.5× 34 924
Yasumitsu Hirano Japan 14 664 1.2× 357 0.9× 308 1.4× 89 0.7× 12 0.1× 124 881

Countries citing papers authored by O Roikjær

Since Specialization
Citations

This map shows the geographic impact of O Roikjær's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by O Roikjær with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites O Roikjær more than expected).

Fields of papers citing papers by O Roikjær

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by O Roikjær. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by O Roikjær. The network helps show where O Roikjær may publish in the future.

Co-authorship network of co-authors of O Roikjær

This figure shows the co-authorship network connecting the top 25 collaborators of O Roikjær. A scholar is included among the top collaborators of O Roikjær based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with O Roikjær. O Roikjær is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
Wilhelmsen, Michael, Sisse Helle Njor, O Roikjær, Morten Arendt Rasmussen, & Ismail Gögenür. (2021). Impact of screening on short-term mortality and morbidity following treatment for colorectal cancer. Scandinavian Journal of Surgery. 110(4). 465–471. 4 indexed citations
2.
Njor, Sisse Helle, Berit Andersen, Lennart Friis‐Hansen, et al.. (2021). The optimal cut‐off value in fit‐based colorectal cancer screening: An observational study. Cancer Medicine. 10(5). 1872–1879. 21 indexed citations
3.
Lykke, Jakob, et al.. (2020). Identification of Risk Factors Associated With Stage III Disease in Nonmetastatic Colon Cancer: Results From a Prospective National Cohort Study. Annals of Coloproctology. 36(5). 316–322. 5 indexed citations
4.
Lykke, Jakob, et al.. (2019). Lymph node yield and tumour subsite are associated with survival in stage I–III colon cancer: results from a national cohort study. World Journal of Surgical Oncology. 17(1). 62–62. 20 indexed citations
5.
Degett, Thea Helene, O Roikjær, Lene Hjerrild Iversen, & Ismail Gögenür. (2017). A model predicting operative mortality in the UK has only limited value in Denmark. International Journal of Colorectal Disease. 33(2). 141–147. 7 indexed citations
6.
Lykke, Jakob, Per Jess, & O Roikjær. (2016). The prognostic value of lymph node ratio in a national cohort of rectal cancer patients. European Journal of Surgical Oncology. 42(4). 504–512. 26 indexed citations
7.
Lykke, Jakob, et al.. (2016). A high lymph node yield in colon cancer is associated with age, tumour stage, tumour sub-site and priority of surgery. Results from a prospective national cohort study. International Journal of Colorectal Disease. 31(7). 1299–1305. 21 indexed citations
8.
Roikjær, O, et al.. (2015). Elderly patients with colorectal cancer are oncologically undertreated. European Journal of Surgical Oncology. 41(3). 421–425. 24 indexed citations
9.
Lykke, Jakob, et al.. (2015). A minimum yield of twelve lymph nodes in rectal cancer remains valid in the era of neo-adjuvant treatment. International Journal of Colorectal Disease. 30(3). 347–351. 9 indexed citations
10.
Lykke, Jakob, Per Jess, & O Roikjær. (2015). Increased Lymph Node Yield Is Associated With Improved Survival in Rectal Cancer Irrespective of Neoadjuvant Treatment. Diseases of the Colon & Rectum. 58(9). 823–830. 31 indexed citations
11.
12.
13.
14.
Callesen, Torben, et al.. (1999). Pain after primary inguinal herniorrhaphy: influence of surgical technique11No competing interests declared.. Journal of the American College of Surgeons. 188(4). 355–359. 29 indexed citations
15.
Bech, K., Torben Callesen, O Roikjær, et al.. (1998). [Organization and results of ambulatory surgery for inguinal hernia].. PubMed. 160(7). 1014–8. 3 indexed citations
16.
Callesen, Torben, Karsten Bech, Jørgen Thorup, et al.. (1998). Cryoanalgesia. Anesthesia & Analgesia. 87(4). 896–899. 33 indexed citations
17.
Callesen, Torben, K. Bech, Jens Andersen, et al.. (1998). Pain after groin hernia repair. British journal of surgery. 85(10). 1412–1414. 91 indexed citations
18.
Pedersen, I. Krogh, F Burcharth, O Roikjær, & H Baden. (1994). Resection of liver metastases from colorectal cancer. Diseases of the Colon & Rectum. 37(11). 1078–1082. 84 indexed citations
19.
Roikjær, O, F Burcharth, Claus Hovendal, et al.. (1992). A double-blinded multicenter trial of somatostatin in the treatment of acute pancreatitis. University of Southern Denmark Research Portal (University of Southern Denmark). 3 indexed citations
20.
Schulze, Svend, et al.. (1988). Epidural bupivacaine and morphine plus systemic indomethacin eliminates pain but not systemic response and convalescence after cholecystectomy.. PubMed. 103(3). 321–7. 90 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

Explore authors with similar magnitude of impact

Breakdown of academic impact, for papers by Bradford J. Kim Breakdown of academic impact, for papers by Patrick J. Broe Breakdown of academic impact, for papers by Etienne Abdelnour‐Berchtold Breakdown of academic impact, for papers by Linda W. Martin Breakdown of academic impact, for papers by Relin Yang Breakdown of academic impact, for papers by W. F. A. Miles Breakdown of academic impact, for papers by J Weerts Breakdown of academic impact, for papers by J. R. T. Monson Breakdown of academic impact, for papers by B. Rumstadt Breakdown of academic impact, for papers by Yasumitsu Hirano
Rankless by CCL
2026