{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T07:32:47Z","timestamp":1765611167897,"version":"3.48.0"},"reference-count":23,"publisher":"BMJ","issue":"11","license":[{"start":{"date-parts":[[2022,11,14]],"date-time":"2022-11-14T00:00:00Z","timestamp":1668384000000},"content-version":"unspecified","delay-in-days":13,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"DOI":"10.13039\/100018286","name":"Dutch Arthritis Society","doi-asserted-by":"publisher","award":["18-2-204"],"award-info":[{"award-number":["18-2-204"]}],"id":[{"id":"10.13039\/100018286","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2022,10,22]]},"published-print":{"date-parts":[[2022,11]]},"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>The incidence of degenerative disorders, including osteoarthritis (OA), increases rapidly in women after menopause. However, the influence of the menopause is still insufficiently investigated due to the slowness of menopausal transition. In this study, a novel human model is used in which it is expected that menopausal-related changes will occur faster. This is the Females discontinuing Oral Contraceptives Use at Menopausal age model. The ultimate aim is to link these changes to OA and other degenerative disorders, including cardiovascular diseases, diabetes, osteoporosis and tendinopathies.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods and analysis<\/jats:title>\n                    <jats:p>This is a pilot observational prospective cohort study with 2\u2009years of follow-up. Fifty women aged 50\u201360 who use oral contraceptive (OC) and have the intention to stop are included. Measurements are performed once before stopping OC, and four times thereafter at 6 weeks, 6 months, 1\u2009year and 2 years. At every time point, a questionnaire is filled in and a sample of blood is drawn. At the first and final time points, a physical examination, hand radiographs and a MRI scan of one knee are performed. The primary OA outcome is progression of the MRI Osteoarthritis Knee Score. Secondary OA outcomes are the development of clinical knee and hand OA, development of knee OA according to the MRI definition, and progression of radiographic features for hand OA. Principal component analysis will be used to assess which changes occur after stopping OC. Univariate and multivariate generalised estimating equation models will be used to test for associations between these components and OA.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Ethics and dissemination<\/jats:title>\n                    <jats:p>The study has been approved by the Medical Ethics Committee of the Erasmus MC University Medical Center Rotterdam (MEC-2019-0592). All participants must give informed consent before data collection. Results will be disseminated in national and international journals.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration number<\/jats:title>\n                    <jats:p>NL70796.078.19.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2022-064779","type":"journal-article","created":{"date-parts":[[2022,11,14]],"date-time":"2022-11-14T12:00:26Z","timestamp":1668427226000},"page":"e064779","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Accelerated menopausal changes as human disease model \u2018FOCUM\u2019 for the development of osteoarthritis and other degenerative disorders: protocol for a prospective cohort study"],"prefix":"10.1136","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6800-6666","authenticated-orcid":false,"given":"Eveline","family":"Molendijk","sequence":"first","affiliation":[{"name":"Department of General Practice, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dieuwke","family":"Schiphof","sequence":"additional","affiliation":[{"name":"Department of General Practice, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Edwin H G","family":"Oei","sequence":"additional","affiliation":[{"name":"Department of Radiology and Nuclear Medicine, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0372-0188","authenticated-orcid":false,"given":"Robert-Jan","family":"de Vos","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics and Sports Medicine, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P Koen","family":"Bos","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics and Sports Medicine, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joyce B J","family":"van Meurs","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics and Sports Medicine, Erasmus Medical Center, Rotterdam, The Netherlands"},{"name":"Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Erik","family":"Lubberts","sequence":"additional","affiliation":[{"name":"Department of Rheumatology, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M Carola","family":"Zillikens","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bram C J","family":"van der Eerden","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maryam","family":"Kavousi","sequence":"additional","affiliation":[{"name":"Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Boris W V","family":"Schouten","sequence":"additional","affiliation":[{"name":"Department of General Practice, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mari\u00eblla I B","family":"de Rooij-Duran","sequence":"additional","affiliation":[{"name":"Service Apotheek Pendrecht, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sita M A","family":"Bierma-Zeinstra","sequence":"additional","affiliation":[{"name":"Department of General Practice, Erasmus Medical Center, Rotterdam, The Netherlands"},{"name":"Department of Orthopaedics and Sports Medicine, Erasmus Medical Center, Rotterdam, The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2022,11,14]]},"reference":[{"key":"2025121223304794000_12.11.e064779.1","unstructured":"VTV-18 . 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