title: Identifying the symptom and functional domains in patients with fibromyalgia: results of a cross-sectional Internet-based survey in Italy.
abstract: OBJECTIVE
  The aims of this cross-sectional study were to investigate the usefulness of using an Internet survey of patients with fibromyalgia in order to obtain information concerning symptoms and functionality and identify clusters of clinical features that can distinguish patient subsets.
  
  
  METHODS
  An Internet website has been used to collect data. Fibromyalgia Impact Questionnaire Revised version, self-administered Fibromyalgia Activity Score, and Self-Administered Pain Scale were used as questionnaires. Hierarchical agglomerative clustering was applied to the data obtained in order to identify symptoms and functional-based subgroups.
  
  
  RESULTS
  Three hundred and fifty-three patients completed the study (85.3% women). The highest scored items were those related to sleep quality, fatigue/energy, pain, stiffness, degree of tenderness, balance problems, and environmental sensitivity. A high proportion of patients reported pain in the neck (81.4%), upper back (70.1%), and lower back (83.2%). A three-cluster solution best fitted the data. The variables were significantly different (P<0.0001) among the three clusters: cluster 1 (117 patients) reflected the lowest average scores across all symptoms, cluster 3 (116 patients) the highest scores, and cluster 2 (120 patients) captured moderate symptom levels, with low depression and anxiety.
  
  
  CONCLUSIONS
  Three subgroups of fibromyalgia samples in a large cohort of patients have been identified by using an Internet survey. This approach could provide rationale to support the study of individualized clinical evaluation and may be used to identify optimal treatment strategies.
authors.affiliation: Rheumatology Department, Polytechnic University of Marche, Jesi (Ancona), Parma, Italy.
authors.forename: Fausto
authors.initials: F
authors.lastname: Salaffi
authors.affiliation: Department of Internal Medicine and Rheumatology, University Hospital of Parma, Parma, Italy.
authors.forename: Flavio
authors.initials: F
authors.lastname: Mozzani
authors.affiliation: Rheumatology Department, Polytechnic University of Marche, Jesi (Ancona), Parma, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Draghessi
authors.affiliation: IRCCS Galeazzi Orthopedic Department, Milan, Italy.
authors.forename: Fabiola
authors.initials: F
authors.lastname: Atzeni
authors.affiliation: Department of Internal Medicine and Rheumatology, University Hospital of Parma, Parma, Italy.
authors.forename: Rosita
authors.initials: R
authors.lastname: Catellani
authors.affiliation: Rheumatology Department, Betsi Cadwaladr University Health Board, Glan Clwyd Hospital, Bodelwyddan, Denbighshire, Wales, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ciapetti
authors.affiliation: Rheumatology Department, Polytechnic University of Marche, Jesi (Ancona), Parma, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Di Carlo
authors.affiliation: Rheumatology Department, L. Sacco University Hospital, Milan, Italy.
authors.forename: Piercarlo
authors.initials: P
authors.lastname: Sarzi-Puttini
keywords: FAS; FIQR; Internet; SAPS; cluster analysis; fibromyalgia; pain