title: Characteristics of patients contacting a center for undiagnosed and rare diseases.
abstract: Little is known about the characteristics of patients seeking help from dedicated centers for undiagnosed and rare diseases. However, information about their demographics, symptoms, prior diagnoses and medical specialty is crucial to optimize these centers' processes and infrastructure.
  
  
  
  Using a questionnaire, structured information from 522 adult patients contacting a center for undiagnosed and rare diseases was obtained. The information included basic sociodemographic data (age, gender, insurance status), previous hospital admissions, primary symptoms of complaint and previously determined diagnosis.
  
  
  
  The majority of patients completing the questionnaire were female, 300 (57 %) vs. 222 men (43 %). The median age was 52 years (range 18-92). More than half, 309 (59 %), of our patients had never been admitted to a university hospital. Common diagnoses included other soft tissue disorders, not classified elsewhere (ICD M79, n = 63, 15.3 %), somatoform disorders (ICD F45, n = 51, 12.3 %) and other polyneuropathies (ICD G62, n=36, 8.7 %). The most frequent symptoms were general weakness (n = 180, 36.6 %) followed by arthralgia (n = 124, 25.2 %) and abdominal discomfort (n = 113, 23.0 %). The majority of patients had either internal medicine (81.3 %) and/or neurologic (37.6 %) health problems.
  
  
  
  Pain-associated diagnoses and the typical "unexplained" medical conditions (chronic fatigue syndrome, fibromyalgia, irritable bowel syndrome) are frequent among people contacting a center dedicated to undiagnosed diseases. The chief symptoms are mostly unspecific. An interdisciplinary organizational approach involving mainly internal medicine, neurology and psychiatry/psychosomatic care is needed.
authors.affiliation: Center for undiagnosed and rare diseases, University clinic Marburg, Baldinger Str. 1, D-35043, Marburg, Germany. tobias.mueller@staff.uni-marburg.de.
authors.forename: Tobias
authors.identifier: 0000-0003-0269-634X
authors.initials: T
authors.lastname: Mueller
authors.affiliation: Center for undiagnosed and rare diseases, University clinic Marburg, Baldinger Str. 1, D-35043, Marburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Jerrentrup
authors.affiliation: Center for undiagnosed and rare diseases, University clinic Marburg, Baldinger Str. 1, D-35043, Marburg, Germany.
authors.forename: Max Jakob
authors.initials: MJ
authors.lastname: Bauer
authors.affiliation: Information technology Department, University clinic Marburg, Baldinger Str. 1, D-35043, Marburg, Germany.
authors.forename: Hans Walter
authors.initials: HW
authors.lastname: Fritsch
authors.affiliation: Center for undiagnosed and rare diseases, University clinic Marburg, Baldinger Str. 1, D-35043, Marburg, Germany.
authors.forename: Juergen Rolf
authors.initials: JR
authors.lastname: Schaefer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis / Q000473:pathology; D005260:Female; D005356:Fibromyalgia / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000175:diagnosis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011115:Polyneuropathies / Q000175:diagnosis / Q000473:pathology; D035583:Rare Diseases / Q000175:diagnosis* / Q000473:pathology; D013001:Somatoform Disorders / Q000175:diagnosis / Q000473:pathology; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Rare disease epidemiology; Undiagnosed disease program; Undiagnosed diseases