title: Validity and reliability of an Italian version of the revised Leeds disability questionnaire for patients with ankylosing spondylitis.
abstract: OBJECTIVE
  The purpose of the present study was to produce an Italian version of the Revised Leeds Disability Questionnaire (LDQ) in a group of patients with ankylosing spondylitis, and to examine the psychometric properties of this version, evaluating its internal consistency, external validity and reliability.
  
  
  METHODS
  The LDQ was administered to 60 Caucasian patients affected by ankylosing spondylitis (50 males, 10 females, mean age 46.1 +/- 14.2 yr, range 22-74, median disease duration 4.5 yr, range 1-24) together with the Italian version of the Stanford Health Assessment Questionnaire (HAQ), and anthropometric measurements. Thirty patients completed the questionnaire after a 10-day interval. Internal consistency was evaluated with Cronbach's alpha coefficient of reliability. Construct validity of the LDQ was evaluated using the correlation between the HAQ and anthropometric measurements. Test-retest reliability was assessed with the intraclass correlation coefficient.
  
  
  RESULTS
  All patients completed the validation study. The questionnaire was internally consistent (alpha=0.90). A significant correlation was recorded between the LDQ and the HAQ score (rho=0.841, P<0.01) and the anthropometric measurements. Test-retest reliability showed a good correlation coefficient (intraclass correlation=0.97).
  
  
  CONCLUSIONS
  The Italian LDQ is a valid and reliable instrument for detecting and measuring functional disability in patients with ankylosing spondylitis. Our results confirm the utility of this questionnaire as a valid and feasible functional measure for patients with ankylosing spondylitis.
authors.affiliation: Fondazione Maugeri, IRCCS, Istituto Telese Terme, Rheumatology and Rehabilitation Research Unit, Telese Terme (BN), Campania, Italy. enniolubrano@hotmail.com
authors.forename: E
authors.initials: E
authors.lastname: Lubrano
authors.forename: P
authors.initials: P
authors.lastname: Sarzi Puttini
authors.forename: W J
authors.initials: WJ
authors.lastname: Parsons
authors.forename: S
authors.initials: S
authors.lastname: D'Angelo
authors.forename: M A
authors.initials: MA
authors.lastname: Cimmino
authors.forename: F
authors.initials: F
authors.lastname: Serino
authors.forename: N
authors.initials: N
authors.lastname: Pappone
mesh_terms: D000328:Adult; D000368:Aged; D000886:Anthropometry / Q000379:methods; D003431:Cross-Cultural Comparison; D004185:Disability Evaluation; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D013167:Spondylitis, Ankylosing / Q000503:physiopathology / Q000534:rehabilitation*; D011795:Surveys and Questionnaires