Health-related quality of life in patients with cleft palate : validity and reliability of the VPI effects on life outcomes (VELO) questionnaire translated to Dutch

Abstract

BACKGROUND : Disease-specific health-related quality of life (HRQOL) questionnaires provide the clinician with important information regarding the impact of the disease on functioning and well-being. For patients with velopharyngeal insufficiency (VPI), the VPI Effects on Life Outcomes (VELO) questionnaire was developed and validated in English by Skirko et al. (2012). However, a valid and reliable Dutch translation of this questionnaire is not available yet. METHODS : The English questionnaire was translated to Dutch following a forward-backward translation procedure. A linguistic validation and the evaluation of the internal consistency (Cronbach's α) of this Dutch version were performed based on the responses of 39 parents of patients with cleft (lip and) palate (mean age: 6.8 years) (parent report) and the responses of 14 patients older than 8 years (mean age: 9.5 years) (child report). Additionally, the concurrent validity was assessed by comparing the scores on the parent report to those on the pediatric voice handicap index. Furthermore, the validity of the parent proxy assessment and the relationship between age and responses on the VELO questionnaire were investigated. Based on the responses of an age and gender matched control group without cleft palate, the discriminant validity was evaluated. RESULTS : The parent report was easy to complete for all parents. Nine of the fourteen (64%) patients were able to complete the child report independently. The median scores on the parent report and the child report were 82.7 and 95.1 respectively. The patient group had a significantly worse perception of HRQOL compared to the control group (p < 0.001; p = 0.029). There were no significant differences between the responses of the parent and their child's (p = 0.345). A significant positive correlation was found between the score on the parent report and the age of the patients (p = 0.001). Furthermore, a significant negative correlation was found between the parent report and the P-VHI (p < 0.001). Cronbach's α was 0.955 and 0.817 for the parent report and the child report respectively. CONCLUSION : The Dutch VELO questionnaire is a valid, reliable and user-friendly tool that provides important information about HRQOL in patients with cleft (lip and) palate.