Validity and responsiveness of VELO: a velopharyngeal insufficiency quality of life measure.

Abstract

Test the Velopharyngeal Insufficiency (VPI) Effects on Life Outcomes (VELO) instrument for validity, reliability, and responsiveness. Observational cohort. Academic tertiary medical center. Children with VPI (n = 59) and their parents (n = 84) were prospectively enrolled from a pediatric VPI clinic. Pediatric speech language pathologists diagnosed VPI using perceptual speech analysis and rated VPI severity and speech intelligibility deficit (each as minimal, mild, moderate, or severe). All parents and youth 8+ years old (n = 24) completed the VELO instrument and other quality-of-life questionnaires at baseline; the first 40 subjects completed the VELO instrument again 2 weeks later. Treatments included Furlow palatoplasty (n = 20), sphincter pharyngoplasty (n = 14), or an obturator (n = 2), and 29 of 36 (81%) subjects completed the questionnaires 3 months posttreatment. VELO was tested with correlations for criterion validity against VPI severity, construct validity against speech intelligibility and velopharyngeal gap size, and concurrent validity against other quality-of-life measures (r > .40 demonstrating validity); for test-retest reliability using intraclass correlation (>.6 demonstrating reliability); and for responsiveness with the 3-month posttreatment measure using the paired t test. Parental responses are reported; youth responses showed similar results. The VELO instrument did not meet criterion validity (r = -.18, P = .10), or functional construct validity (r = -.37, P = .001), but did meet anatomic construct and concurrent validity (each r > .50, P < .01). VELO scores demonstrated excellent test-retest reliability (r = .85, P < .001) and responsiveness (baseline 54 ± 14 to posttreatment 70 ± 18, P < .001). VELO provides a VPI-specific quality-of-life instrument that demonstrates concurrent validity, test-retest reliability, and responsiveness to change in quality of life with treatment.