Translation and validation of the Dutch VEINES-QOL/Sym in varicose vein patients
Objectives: To translate from English to Dutch and evaluate the psychometric properties of the VEnous INsufficiency Epidemiological and Economic Studies (VEINES) questionnaire, divided in symptom (VEINES-Sym) and quality of life (VEINES-QOL) subscales. Methods: Standard forward-backward translation method was used to translate the 26 items of the VEINES-QOL/Sym. Eligible patients had to complete a standardized questionnaire. Demographic, venous disease characteristics, clinical venous signs, CEAP (clinical, aetiological, anatomical and pathological elements) classification and ultrasound findings were also noted. If item's scores were in an extreme category in more than 70% of patients a floor or ceiling effect was present. Feasibility of the individual items was considered poor if 5% or more of the responses were missing. The validity was tested by comparing the VEINES-QOL/Sym scores to the Short Form 36 (SF-36) scores and across the different 'CEAP' categories. Confirmatory factor analysis was used to assess the underlying structure of the VEINES-QOL/Sym. Results: Sixty-six patients were included (response rate of 72%). None of the 26 items missed <10% of responses, but two showed ceiling effect. Both the VEINES-QOL and VEINES-Sym showed an excellent internal consistency (Cronbach's alpha of 0.88 and 0.81, respectively). The VEINES-QOL demonstrated a good construct validity for the physical component of the SF-36, but not for the mental component (rho = 0.62 and 0.22, respectively), as expected. The VEINES-Sym correlated poorly to both SF-36's components. According to the confirmatory principle axis factoring, only three out of 25 items did not load sufficiently on the factor. Conclusions: The Dutch VEINES-QOL/Sym can be used for health-related quality of life research in varicose veins patients and the evaluation of therapies.