title: The individualized neuromuscular quality of life questionnaire: cultural translation and psychometric validation for the Dutch population.
abstract: BACKGROUND
  In this study we describe the translation and psychometric evaluation of the Dutch Individualized Neuromuscular Quality of Life (INQoL) questionnaire.
  
  
  METHODS
  Backward and forward translation of the questionnaire was executed, and psychometric properties were assessed on the basis of reliability and validity.
  
  
  RESULTS
  Two hundred six patients were included in the study. Reliability analyses resulted in Cronbach alpha values of >0.70 for all subdomains. Known-group validity showed a significant correlation between INQoL scores and severity as well as age for the majority of subdomains. Item-total correlation for overall quality of life was satisfactory. Concurrent validity with the SF-36 and EQ-5D was good (range of Spearman correlation coefficients -0.43 to -0.76).
  
  
  CONCLUSIONS
  This study resulted in a questionnaire that is appropiate for use in the Dutch-speaking population to measure quality of life among patients with a wide variety of muscle disorders. This confirms and extends data obtained in the UK, US, Italy, and Serbia.
authors.affiliation: Department of Neurology, Radboud University Medical Centre, 935 Neurology, Reinier Postlaan 4, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
authors.forename: Femke M
authors.initials: FM
authors.lastname: Seesing
authors.forename: Lisanne Ewm
authors.initials: LE
authors.lastname: van Vught
authors.forename: Michael R
authors.initials: MR
authors.lastname: Rose
authors.forename: Gea
authors.initials: G
authors.lastname: Drost
authors.forename: Baziel G M
authors.initials: BG
authors.lastname: van Engelen
authors.forename: Gert-Jan
authors.initials: GJ
authors.lastname: van der Wilt
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003469:Culture; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases / Q000453:epidemiology*; D009426:Netherlands / Q000453:epidemiology; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014177:Translations
keywords: INQoL; muscle disease; outcome; patient-reported; quality of life; validation