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

Objective: Test the Velopharyngeal Insufficiency (VPI) Effects on Life Outcomes (VELO) instrument for validity, reliability, and responsiveness.

Study design: Observational cohort.

Setting: Academic tertiary medical center.

Subjects: Children with VPI (n = 59) and their parents (n = 84) were prospectively enrolled from a pediatric VPI clinic.

Methods: 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.

Results: 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).

Conclusion: 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.