title: Diagnostic needs for rare diseases and shared prediagnostic phenomena: Results of a German-wide expert Delphi survey.
abstract: BACKGROUND
  Worldwide approximately 7,000 rare diseases have been identified. Accordingly, 4 million individuals live with a rare disease in Germany. The mean time to diagnosis is about 6 years and patients receive several incorrect diagnoses during this time. A multiplicity of factors renders diagnosing a rare disease extremely difficult. Detection of shared phenomena among individuals with different rare diseases could assist the diagnostic process. In order to explore the demand for diagnostic support and to obtain the commonalities among patients, a nationwide Delphi survey of centers for rare diseases and patient groups was conducted.
  
  
  METHODS
  A two-step Delphi survey was conducted using web-based technologies in all centers for rare diseases in Germany. Moreover, the leading patient support group, the German foundation for rare diseases (ACHSE), was contacted to involve patients as experts in their disease. In the survey the experts were invited to name rare diseases with special need for diagnostic improvement. Secondly, communal experiences of affected individuals were collected.
  
  
  RESULTS
  166 of 474 contacted experts (35%) participated in the first round of the Delphi process and 95 of 166 (57%) participated in the second round. Metabolic (n = 74) and autoimmune diseases (n = 39) were ranked the highest for need for diagnostic support. For three diseases (i.e. scleroderma, Pompe's disease, and pulmonary arterial hypertension), a crucial need for diagnostic support was explicitly stated. A typical experience of individuals with a rare disease was stigmatization of having psychological or psychosomatic problems. In addition, most experts endured an 'odyssey' of seeing many different medical specialists before a correct diagnosis (n = 38) was confirmed.
  
  
  CONCLUSIONS
  There is need for improving the diagnostic process in individuals with rare diseases. Shared experiences in individuals with a rare disease were observed, which could possibly be utilized for diagnostic support in the future.
authors.affiliation: Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Hannover, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Blöß
authors.affiliation: Center for Chronic Immunodeficiency (CCI), University Medical Center Freiburg, University of Freiburg, Freiburg, Germany.|Center for Pediatric and Adolescent Medicine, University Medical Center Freiburg, University of Freiburg, Freiburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Klemann
authors.affiliation: Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Hannover, Germany.
authors.forename: Ann-Katrin
authors.initials: AK
authors.lastname: Rother
authors.affiliation: Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Hannover, Germany.|Department of Neurology, Hannover Medical School, Hannover, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Mehmecke
authors.affiliation: DRK Clementinenkrankenhaus, Hannover, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Schumacher
authors.affiliation: Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Hannover, Germany.
authors.forename: Urs
authors.initials: U
authors.lastname: Mücke
authors.affiliation: Center for Rare Diseases Bonn (ZSEB), University Hospital of Bonn, Bonn, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Mücke
authors.affiliation: Center for Rare Diseases Bonn (ZSEB), University Hospital of Bonn, Bonn, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Stieber
authors.affiliation: Ostfalia University of Applied Sciences, Wolfenbuettel, Germany.|Helmholtz Centre for Infection Research, Braunschweig, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Klawonn
authors.affiliation: Ostfalia University of Applied Sciences, Wolfenbuettel, Germany.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Kortum
authors.affiliation: Improved Medical Diagnostics IMD GmbH, Hannover, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Lechner
authors.affiliation: Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Hannover, Germany.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Grigull
mesh_terms: D000328:Adult; D001327:Autoimmune Diseases / Q000175:diagnosis; D057210:Delayed Diagnosis; D003697:Delphi Technique; D005260:Female; D005858:Germany; D006009:Glycogen Storage Disease Type II / Q000175:diagnosis; D006801:Humans; D006973:Hypertension / Q000145:classification / Q000175:diagnosis; D008297:Male; D008659:Metabolic Diseases / Q000175:diagnosis; D008875:Middle Aged; D035583:Rare Diseases / Q000175:diagnosis*; D012595:Scleroderma, Systemic / Q000175:diagnosis; D012657:Self-Help Groups / Q000458:organization & administration*; D012944:Social Support