title: Reliability and validity of an instrument to measure quality of life in the dysarthric speaker.
abstract: OBJECTIVE
  To develop a tool to measure quality of life (QOL) in the dysarthric speaker (QOL-DyS).
  
  
  METHODS
  The study consisted of two phases: scale development and item reduction (phase 1), and reliability and validity analysis (phase 2). The 100-item 'Dysarthria from the Point of View of the Dysarthric Patient' questionnaire was used for item development; the data from 50 dysarthric patients were measured for internal consistency and the 40-item QOL-DyS was developed. A second group of 50 dysarthric patients and 30 control participants were recruited for phase 2. Internal consistency and test-retest reliability were analyzed through Cronbach's α coefficient and intraclass correlation coefficient (ICC), respectively. The scores obtained from the pathological and the control group were compared using the Mann-Whitney test. Finally, the correlation between the QOL-DyS and dysarthria severity was assessed using the Spearman test.
  
  
  RESULTS
  An excellent internal consistency (α = 0.90) and test-retest reliability (ICC = 0.98, 95% CI: 0.97-0.99) were found; the score difference between the dysarthric and control groups was significant (p < 0.001). The QOL-DyS scores correlated positively with the severity of dysarthria (r = 0.43).
  
  
  CONCLUSIONS
  The QOL-DyS is a reliable and valid tool to assess QOL in patients with dysarthria.
authors.affiliation: Department of Clinical Sciences L. Sacco, Università degli Studi di Milano, Fondazione Don Gnocchi Onlus, IRCCS, Milan, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Piacentini
authors.forename: Annalisa
authors.initials: A
authors.lastname: Zuin
authors.forename: Davide
authors.initials: D
authors.lastname: Cattaneo
authors.forename: Antonio
authors.initials: A
authors.lastname: Schindler
mesh_terms: D000223:Adaptation, Psychological; D000293:Adolescent; D000328:Adult; D000368:Aged; D003144:Communication Barriers; D004401:Dysarthria / Q000209:etiology / Q000523:psychology*; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000150:complications; D011446:Prospective Studies; D011788:Quality of Life; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult