title: Cross-cultural adaptation and validation of the Italian version of the Western Ontario Osteoarthritis of the Shoulder index (WOOS).
abstract: BACKGROUND
  The Western Ontario Osteoarthritis of the Shoulder index (WOOS) has been introduced as a disease-specific quality of life measurement in patients with glenohumeral arthritis. The aim of the present study was to perform a cross-cultural adaptation of the English version of the WOOS to Italian and to assess its validity, reliability and responsiveness in patients with glenohumeral joint osteoarthritis treated conservatively.
  
  
  METHODS
  The adaptation process was carried out following the simplified Guillemin criteria. The English version was translated into Italian by two bilingual orthopaedic surgeons and then translated back into English by two different bilingual orthopaedic surgeons. The original version was compared with the back-translation. The questionnaire was prospectively administered to 30 patients with glenohumeral osteoarthritis at baseline and again after 5 days for retest reliability. After 6 months of conservative treatment, the responsiveness of the questionnaire was assessed in a subsample of 20 patients. The level of statistical significance was set at 0.05.
  
  
  RESULTS
  The interclass correlation coefficient between test and retest of the WOOS was 0.99 (P < 0.001). Pearson's correlation coefficient between the WOOS and disability of the arm, shoulder and hand (DASH) preoperatively was 0.73 (P < 0.01) and the correlation between the changes of score for the WOOS and DASH was 0.75 (P < 0.01). There were no floor or ceiling effects. Responsiveness, calculated by standardized response mean, was 1.1 and effect size was 1.3.
  
  
  CONCLUSIONS
  The Italian version of the WOOS questionnaire has shown to be equivalent to its English version and demonstrated good validity, reliability and responsiveness to conservative treatment of glenohumeral osteoarthritis.
  
  
  METHODS
  Level II.
authors.affiliation: Science for Health Department, Molise University, Via De Sanctis, 86100, Campobasso, Italy.
authors.forename: Katia
authors.initials: K
authors.lastname: Corona
authors.affiliation: Catholic University of Rome, Largo Francesco Vito 1, 00168, Rome, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Cerciello
authors.affiliation: Lexington Clinic Orthopedics-Sports Medicine Center, The Shoulder Center of Kentucky, Lexington, USA.
authors.forename: Brent Joseph
authors.initials: BJ
authors.lastname: Morris
authors.affiliation: Ospedali Riuniti Padova Sud-ULSS 17, Schiavonia (PD), Italy. e.visona@libero.it.
authors.forename: Enrico
authors.identifier: http://orcid.org/0000-0001-7074-6308
authors.initials: E
authors.lastname: Visonà
authors.affiliation: Unit of Shoulder and Elbow Surgery, D. Cervesi Hospital, Cattolica-AUSL della Romagna Ambito Territoriale di Rimini, Cattolica, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Merolla
authors.affiliation: Unit of Shoulder and Elbow Surgery, D. Cervesi Hospital, Cattolica-AUSL della Romagna Ambito Territoriale di Rimini, Cattolica, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Porcellini
mesh_terms: D003466:Cultural Characteristics; D004185:Disability Evaluation; D006801:Humans; D007558:Italy; D010003:Osteoarthritis / Q000145:classification* / Q000503:physiopathology* / Q000628:therapy; D010147:Pain Measurement; D011446:Prospective Studies; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D012785:Shoulder Joint; D014177:Translations
keywords: Cross-cultural adaptation; Shoulder osteoarthritis; Validation; Western Ontario Osteoarthritis of the Shoulder index