{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,28]],"date-time":"2026-08-28T22:50:52Z","timestamp":1787957452986,"version":"build-2784847793"},"reference-count":51,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2015,12,21]],"date-time":"2015-12-21T00:00:00Z","timestamp":1450656000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"funder":[{"name":"Medstar Research Institute","award":["NCT00888563"],"award-info":[{"award-number":["NCT00888563"]}]},{"name":"Division of Intramural Research of the National Institute of Nursing Research"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Arthritis Care &amp;amp; Research"],"published-print":{"date-parts":[[2016,1]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To develop a symptoms cluster model that can describe factors of fibromyalgia syndrome (FMS) associated with fatigue severity as reported by the sample and to explore FMS clinical symptom subclusters based on varying symptom intensities.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>FMS individuals (n\u2009=\u2009120, 82% ages 31\u201360 years, 90% women, 59% white) diagnosed with the 1990 or 2010 American College of Rheumatology diagnostic criteria were enrolled. Participants completed multiple validated self\u2010report questionnaires to measure fatigue, pain, depression, anxiety, pain catastrophizing, daytime sleepiness, cognitive function, and FMS\u2010related polysymptomatic distress. Cluster analysis using SPSS 19.0 and structural equation modeling using AMOS 17.0 were used.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Final structural equation modeling the symptoms cluster model showed good fit and revealed that FMS fatigue was associated with widespread pain, symptoms severity, pain intensity, pain interference, cognitive dysfunction, catastrophizing, anxiety, and depression (\u03c7\n                      <jats:sup>2<\/jats:sup>\n                      \u2009=\u2009121.72 (98df),\n                      <jats:italic>P<\/jats:italic>\n                      &gt; 0.05, \u03c7\n                      <jats:sup>2<\/jats:sup>\n                      \/df\u2009=\u20091.242, comparative fit index\u2009=\u20090.982, root mean square error of approximation\u2009=\u20090.045). Two distinct clinical symptom subclusters emerged: subcluster 1 (78% of total subjects), defined by widespread pain, unrefreshed waking, and somatic symptoms, and subcluster 2 (22% of total subjects), defined by fatigue and cognitive dysfunction with pain being a less severe and less widespread occurrence.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Overall, subcluster 1 had more intense symptoms than subcluster 2. FMS symptoms may be categorized into 2 clinical subclusters. These findings have implications for an illness whose diagnosis and management are symptom dependent. A longitudinal study capturing the variability in the symptom experience of FMS subjects is warranted.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/acr.22626","type":"journal-article","created":{"date-parts":[[2015,5,27]],"date-time":"2015-05-27T14:07:30Z","timestamp":1432735650000},"page":"99-107","source":"Crossref","is-referenced-by-count":28,"title":["Understanding the Association of Fatigue With Other Symptoms of Fibromyalgia: Development of a Cluster Model"],"prefix":"10.1002","volume":"68","author":[{"given":"Nada","family":"Lukkahatai","sequence":"first","affiliation":[{"name":"School of Nursing, University of Nevada, Las Vegas, and National Institute of Nursing Research, NIH Bethesda Maryland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Brian","family":"Walitt","sequence":"additional","affiliation":[{"name":"National Institute of Nursing Research, NIH, Bethesda, Maryland, and Medstar Research Institute, Washington Hospital Center Washington DC"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexandra","family":"Espina","sequence":"additional","affiliation":[{"name":"National Institute of Nursing Research, NIH Bethesda Maryland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alves","family":"Gelio","sequence":"additional","affiliation":[{"name":"National Center for Biotechnology Information, National Library of Medicine Bethesda Maryland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leorey N.","family":"Saligan","sequence":"additional","affiliation":[{"name":"National Institute of Nursing Research, NIH Bethesda Maryland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2015,12,21]]},"reference":[{"key":"e_1_2_6_2_1","doi-asserted-by":"publisher","DOI":"10.1002\/acr.20156"},{"key":"e_1_2_6_3_1","doi-asserted-by":"publisher","DOI":"10.1002\/acr.21896"},{"key":"e_1_2_6_4_1","first-page":"175","article-title":"Cancer\u2010related fatigue: a multidimensional syndrome","volume":"8","author":"Bruera E.","year":"2010","journal-title":"J Support Oncol"},{"key":"e_1_2_6_5_1","doi-asserted-by":"publisher","DOI":"10.1002\/art.20841"},{"key":"e_1_2_6_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejca.2007.01.024"},{"key":"e_1_2_6_7_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10549-007-9831-1"},{"key":"e_1_2_6_8_1","doi-asserted-by":"publisher","DOI":"10.1177\/135910539900400103"},{"key":"e_1_2_6_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(04)15794-2"},{"key":"e_1_2_6_10_1","first-page":"251","volume-title":"Translational pain research: from mouse to man","author":"Light AR","year":"2010"},{"key":"e_1_2_6_11_1","first-page":"564","article-title":"\u201cFunctional\u201d or \u201cpsychosomatic\u201d symptoms, e.g. a flu\u2010like malaise, aches and pain and fatigue, are major features of major and in particular of melancholic depression","volume":"30","author":"Maes M.","year":"2009","journal-title":"Neuro Endocrinol Lett"},{"key":"e_1_2_6_12_1","doi-asserted-by":"publisher","DOI":"10.1186\/1745-6215-10-24"},{"key":"e_1_2_6_13_1","doi-asserted-by":"publisher","DOI":"10.7326\/0003-4819-146-10-200705150-00006"},{"key":"e_1_2_6_14_1","doi-asserted-by":"publisher","DOI":"10.1037\/a0029773"},{"key":"e_1_2_6_15_1","doi-asserted-by":"publisher","DOI":"10.1002\/acr.21949"},{"key":"e_1_2_6_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0304-3959(02)00300-7"},{"key":"e_1_2_6_17_1","doi-asserted-by":"publisher","DOI":"10.1348\/000711201161163"},{"key":"e_1_2_6_18_1","doi-asserted-by":"publisher","DOI":"10.1097\/01.ajp.0000135236.12705.2d"},{"key":"e_1_2_6_19_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jpsychores.2012.11.006"},{"key":"e_1_2_6_20_1","unstructured":"AaronLA.The moderating effects of catastrophizing as a response to daily pain in patients with fibromyalgia [thesis]. 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