title: Cross-cultural adaptation, reliability and validity of the Turkish version of the Chronic Venous Disease Quality of Life Questionnaire (CIVIQ-20).
abstract: BACKGROUND
  Chronic venous disease (CVD) is a well-defined and known disorder which impact on related-health quality of life (QoL). The Chronic Venous Insufficiency Quality of Life Questionnaire (CIVIQ) is a disease-specific instrument to measure the impact of chronic venous insufficiency on patients' lives. The purpose of this study is to cross-culturally adapted the Chronic Venous Disease Quality of Life Questionnaire (CIVIQ-20) for Turkish-speaking patients and determine the psychometric properties of reliability, validity and factor structure in a Turkish population with CVD.
  
  
  METHODS
  The CIVIQ-20 was translated into Turkish and culturally adapted using a double forward-backward protocol according to established guidelines. Individuals (n = 140) with venous diseases completed the CIVIQ-20, Venous Insufficiency Epidemiological and Economic Study (VEINES-QoL/Sym) and Nottingham Health Profile (NHP) questionnaires at baseline and 1 month later.
  
  
  RESULTS
  Cronbach's α value was 0.93. Test-retest reliability was determined as moderate (ICC2:1 = 0.80). There was a significant correlation between CIVIQ-Tk and Nottingham and VEINES-QoL total scores (Nottingham 1: r = 0.770; p < 0.00, Nottingham 2: r = 0.7000; p < 0) (VEINES-QoL: r = -0.574; p < 0.00, VEINES-QoL 2: -0.592, p: 0.00). The measurement error were calculated from SEM and MDC90. The SEM was 2.63 and the MDC90 was 5.79. Exploratory factor analysis demonstrated a three factor structure that explained 56.32 % of total variance.
  
  
  CONCLUSIONS
  The CVIQ-20 Turkish is a reliable and valid instrument for Turkish speaking patients with chronic venous insufficiency.
authors.affiliation: The Institute of Health Sciences, School of Physical Therapy and Rehabilitation, Abant İzzet Baysal University, 14130 Bolu, Turkey.
authors.forename: Özlem Cinar
authors.initials: ÖC
authors.lastname: Özdemir
authors.affiliation: The Faculty of Health Sciences, Marmara University, Istanbul, Turkey.
authors.forename: Eda
authors.initials: E
authors.lastname: Tonga
authors.affiliation: Department of Biostatistics, Izmir University, Izmir, Turkey.
authors.forename: Agah
authors.initials: A
authors.lastname: Tekindal
authors.affiliation: The Institute of Health Sciences, School of Physical Therapy and Rehabilitation, Abant İzzet Baysal University, 14130 Bolu, Turkey.
authors.forename: Yesim
authors.initials: Y
authors.lastname: Bakar