K. Hagen

1.8k total citations
18 papers, 1.4k citations indexed

About

K. Hagen is a scholar working on Psychiatry and Mental health, Public Health, Environmental and Occupational Health and Physiology. According to data from OpenAlex, K. Hagen has authored 18 papers receiving a total of 1.4k indexed citations (citations by other indexed papers that have themselves been cited), including 15 papers in Psychiatry and Mental health, 5 papers in Public Health, Environmental and Occupational Health and 5 papers in Physiology. Recurrent topics in K. Hagen's work include Migraine and Headache Studies (15 papers), Musculoskeletal pain and rehabilitation (4 papers) and Blood Pressure and Hypertension Studies (2 papers). K. Hagen is often cited by papers focused on Migraine and Headache Studies (15 papers), Musculoskeletal pain and rehabilitation (4 papers) and Blood Pressure and Hypertension Studies (2 papers). K. Hagen collaborates with scholars based in Norway, Netherlands and Spain. K. Hagen's co-authors include Lars Jacob Stovner, John‐Anker Zwart, Gunnar Bovim, GM Terwindt, J.‐A. Zwart, Julio Pascual, L Vatten, LJ Stovner, Jostein Holmen and J-A Zwart and has published in prestigious journals such as Neurology, Headache The Journal of Head and Face Pain and Sleep Medicine.

In The Last Decade

K. Hagen

18 papers receiving 1.3k citations

Peers — A (Enhanced Table)

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

Name	h						Papers	Cites
K. Hagen Norway	16	1.1k	531	361	163	136	18	1.4k
J.‐A. Zwart Norway	15	857 0.8×	437 0.8×	269 0.7×	187 1.1×	102 0.8×	15	1.1k
J-A Zwart Norway	15	979 0.9×	430 0.8×	276 0.8×	95 0.6×	115 0.8×	18	1.2k
Jelena Pavlović United States	23	1.3k 1.2×	567 1.1×	407 1.1×	167 1.0×	224 1.6×	84	1.7k
Anne H. Calhoun United States	24	1.2k 1.1×	611 1.2×	373 1.0×	103 0.6×	137 1.0×	39	1.5k
Grethe Helde Norway	24	1.4k 1.3×	474 0.9×	347 1.0×	176 1.1×	52 0.4×	46	1.9k
Colette Andrée Switzerland	15	1.8k 1.7×	978 1.8×	430 1.2×	177 1.1×	75 0.6×	24	2.0k
Paul Rizzoli United States	20	1.2k 1.1×	645 1.2×	374 1.0×	83 0.5×	64 0.5×	58	1.5k
John‐Anker Zwart Norway	21	725 0.7×	296 0.6×	232 0.6×	140 0.9×	102 0.8×	33	987
Christian Lampl Austria	20	1.3k 1.2×	743 1.4×	424 1.2×	146 0.9×	64 0.5×	42	1.5k
Elena Ruiz de la Torre Italy	14	1.5k 1.4×	823 1.5×	367 1.0×	113 0.7×	61 0.4×	27	1.6k

Countries citing papers authored by K. Hagen

Since Specialization

Citations

This map shows the geographic impact of K. Hagen'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 K. Hagen with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites K. Hagen more than expected).

Fields of papers citing papers by K. Hagen

Since Specialization

Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by K. Hagen. 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 K. Hagen. The network helps show where K. Hagen may publish in the future.

Co-authorship network of co-authors of K. Hagen

This figure shows the co-authorship network connecting the top 25 collaborators of K. Hagen. A scholar is included among the top collaborators of K. Hagen 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 K. Hagen. K. Hagen is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

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18 of 18 papers shown

Hagen, K., et al.. (2018). The relationship between obstructive sleep apnea and insomnia: a population-based cross-sectional polysomnographic study. Sleep Medicine. 54. 126–133. 19 indexed citations

Johnsen, Marianne Bakke, Bendik S. Winsvold, Sigrid Børte, et al.. (2018). The causal role of smoking on the risk of headache. A Mendelian randomization analysis in the HUNT study. European Journal of Neurology. 25(9). 1148–1148. 16 indexed citations

Sandvik, Leiv, et al.. (2015). Early menarche and chronic widespread musculoskeletal complaints‐ Results from the HUNT study. European Journal of Pain. 20(3). 458–464. 11 indexed citations

Heuch, Ivar, et al.. (2014). Blood pressure as a risk factor for headache and migraine: a prospective population‐based study. European Journal of Neurology. 22(1). 156–156. 45 indexed citations

Heuch, Ivar, et al.. (2013). Does high blood pressure reduce the risk of chronic low back pain? The Nord‐Trøndelag Health Study. European Journal of Pain. 18(4). 590–598. 27 indexed citations

Ægidius, Karen, John‐Anker Zwart, K. Hagen, et al.. (2010). Increased headache prevalence in female adolescents and adult women with early menarche. The Head‐HUNT Studies. European Journal of Neurology. 18(2). 321–328. 42 indexed citations

Tronvik, Erling, Lars Jacob Stovner, K. Hagen, Jostein Holmen, & J-A Zwart. (2008). High pulse pressure protects against headache. Neurology. 70(16). 1329–1336. 50 indexed citations

Hagen, K., LJ Stovner, & J-A Zwart. (2007). Potentials and Pitfalls in Analytical Headache Epidemiological Studies—Lessons to be Learned from the Head-HUNT Study. Cephalalgia. 27(5). 403–413. 35 indexed citations

Stovner, Lars Jacob, John‐Anker Zwart, K. Hagen, GM Terwindt, & Julio Pascual. (2006). Epidemiology of headache in Europe. European Journal of Neurology. 13(4). 333–345. 299 indexed citations

10.

Hagen, K., Erik O. Pettersen, Lars Jacob Stovner, Frank Skorpen, & J.‐A. Zwart. (2006). The association between headache and Val158Met polymorphism in the catechol–O–methyltransferase gene: the HUNT Study. The Journal of Headache and Pain. 7(2). 70–74. 47 indexed citations

11.

Aamodt, Anne Hege, Lars Jacob Stovner, K. Hagen, Geir Bråthen, & John‐Anker Zwart. (2006). Headache prevalence related to smoking and alcohol use. The Head‐HUNT Study. European Journal of Neurology. 13(11). 1233–1238. 129 indexed citations

12.

Ægidius, Karen, J.‐A. Zwart, K. Hagen, Berit Schei, & Lars Jacob Stovner. (2006). Oral contraceptives and increased headache prevalence. Neurology. 66(3). 349–353. 66 indexed citations

13.

Zwart, J.‐A., Grete Dyb, K. Hagen, et al.. (2004). Analgesic overuse among subjects with headache, neck, and low-back pain. Neurology. 62(9). 1540–1544. 119 indexed citations

14.

Aamodt, Anne Hege, Berit Borch‐Iohnsen, K. Hagen, et al.. (2004). Headache Prevalence Related to Haemoglobin and Ferritin. The HUNT Study. Cephalalgia. 24(9). 758–762. 33 indexed citations

15.

Hagen, K., et al.. (2003). The co‐occurrence of headache and musculoskeletal symptoms amongst 51 050 adults in Norway.. Headache The Journal of Head and Face Pain. 43(4). 424–424. 6 indexed citations

16.

Hagen, K., L Vatten, LJ Stovner, et al.. (2002). Low Socio-Economic Status is Associated with Increased Risk of Frequent Headache: A Prospective Study of 22718 Adults in Norway. Cephalalgia. 22(8). 672–679. 108 indexed citations

17.

Hagen, K., LJ Stovner, Lars J. Vatten, et al.. (2002). Blood pressure and risk of headache: a prospective study of 22 685 adults in Norway.. PubMed. 72(4). 463–6. 108 indexed citations

18.

Hagen, K., et al.. (2000). Prevalence of Migraine and Non-Migrainous Headache—Head-HUNT, A Large Population-Based Study. Cephalalgia. 20(10). 900–906. 195 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.

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