{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,29]],"date-time":"2026-04-29T19:30:42Z","timestamp":1777491042039,"version":"3.51.4"},"reference-count":42,"publisher":"SAGE Publications","issue":"10","license":[{"start":{"date-parts":[[2020,4,20]],"date-time":"2020-04-20T00:00:00Z","timestamp":1587340800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"funder":[{"name":"Candy Foundation","award":["CEHEAD"],"award-info":[{"award-number":["CEHEAD"]}]},{"DOI":"10.13039\/501100004836","name":"Det Frie Forskningsr\u00e5d","doi-asserted-by":"publisher","award":["9039-00067B"],"award-info":[{"award-number":["9039-00067B"]}],"id":[{"id":"10.13039\/501100004836","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Cephalalgia"],"published-print":{"date-parts":[[2020,9]]},"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Headache is an extremely prevalent disorder with a lifetime prevalence of 90\u201399%. However, a small fraction of people never experiences a headache. Research on people without headache could uncover protective factors in headache, but to our knowledge no study on headache-free individuals has been published. We aim to estimate the prevalence of headache-free individuals among Danish blood donors, and to describe the socio-demographics and health factors of headache-free participants.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Materials and methods<\/jats:title>\n                    <jats:p>In all, 38,557 healthy volunteers were recruited as part of the Danish Blood Donor Study. Headache-free participants were identified based on the question \u201cHave you ever experienced a headache of any kind?\u201d. Utilising the Danish registries and self-reported questionnaires, we analysed socio-demographic and lifestyle factors using logistic regression adjusted for age and sex.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The prevalence of headache-free individuals was 4.1% (n\u2009=\u20091362) with a female-male ratio of 1:2.2. To be headache free was significantly associated with an employment status as a student, a low level of income and a regular alcohol consumption.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>The prevalence of headache-free individuals was comparable to population-wide studies of headache. To be headache free was not associated with a high socio-economic status. Further studies on people without headache will hopefully reveal protective factors in headache, and this novel approach might be useful in other very prevalent disorders.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/0333102420920653","type":"journal-article","created":{"date-parts":[[2020,4,20]],"date-time":"2020-04-20T23:19:33Z","timestamp":1587424773000},"page":"1055-1062","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":9,"title":["Prevalence and socio-demographic characteristics of persons who have never had a headache among healthy voluntary blood donors \u2013 a population-based study"],"prefix":"10.1177","volume":"40","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7500-8045","authenticated-orcid":false,"given":"Isa Amalie","family":"Olofsson","sequence":"first","affiliation":[{"name":"Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lisette","family":"Kogelman","sequence":"additional","affiliation":[{"name":"Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andreas","family":"Rasmussen","sequence":"additional","affiliation":[{"name":"Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christian","family":"Erikstrup","sequence":"additional","affiliation":[{"name":"Department of Clinical Immunology, Aarhus University Hospital, Aarhus, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Erik","family":"S\u00f8rensen","sequence":"additional","affiliation":[{"name":"Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1281-1567","authenticated-orcid":false,"given":"Helene M","family":"Paarup","sequence":"additional","affiliation":[{"name":"Department of Clinical Immunology, Odense University Hospital, Odense, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Henrik","family":"Hjalmgrim","sequence":"additional","affiliation":[{"name":"Department of Epidemiological Research, Statens Serum Institut, Copenhagen, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Karina","family":"Banasik","sequence":"additional","affiliation":[{"name":"Novo Nordisk Foundation Center for Protein Research, Copenhagen University, Copenhagen, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kaspar Ren\u00e9","family":"Nielsen","sequence":"additional","affiliation":[{"name":"Department of Clinical Immunology, Aalborg University Hospital, Aalborg, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kristoffer Soelvsten","family":"Burgdorf","sequence":"additional","affiliation":[{"name":"Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ole Birger Vesterager","family":"Pedersen","sequence":"additional","affiliation":[{"name":"Department of Clinical Immunology, Naestved Hospital, Naestved, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Henrik","family":"Ullum","sequence":"additional","affiliation":[{"name":"Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jes","family":"Olesen","sequence":"additional","affiliation":[{"name":"Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thomas Folkmann","family":"Hansen","sequence":"additional","affiliation":[{"name":"Danish Headache Center, Department of Neurology, Rigshospitalet, Glostrup, Denmark"},{"name":"Novo Nordisk Foundation Center for Protein Research, Copenhagen University, Copenhagen, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2020,4,20]]},"reference":[{"key":"bibr1-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1046\/j.1468-2982.2003.00468.x"},{"key":"bibr2-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1016\/0895-4356(91)90147-2"},{"key":"bibr3-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1111\/j.1468-2982.1981.tb00016.x"},{"key":"bibr4-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.42.6.1225"},{"key":"bibr5-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(18)32279-7"},{"key":"bibr6-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1136\/bmjopen-2012-000962"},{"key":"bibr7-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1007\/s10654-004-6519-2"},{"key":"bibr8-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1080\/08998280.2005.11928028"},{"key":"bibr9-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1136\/jcp.45.9.756"},{"key":"bibr10-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1517\/17460441.2015.1041497"},{"key":"bibr11-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1155\/2012\/401965"},{"key":"bibr12-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1111\/j.1423-0410.2011.01553.x"},{"key":"bibr13-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0169112"},{"key":"bibr14-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1016\/j.cmpb.2016.07.023"},{"key":"bibr15-0333102420920653","doi-asserted-by":"publisher","DOI":"10.1097\/00005650-199603000-00003"},{"key":"bibr16-0333102420920653","doi-asserted-by":"crossref","unstructured":"Gandek 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