Reliability and validity of the pediatric posterior drooling scale

Abstract

Background Drooling is a frequent problem in children with neurological disabilities. Drooling can be distinguished in anterior and posterior. Posterior drooling is described as saliva dripping into the pharynx, creating a risk of aspiration which can lead to substantial respiratory morbidity. Valid and reliable diagnostics are needed, but not yet available. Therefore, the Pediatric Posterior Drooling Scale (PPDS) is developed, but its psychometric properties are unknown. Research question What is the intra-rater, inter-rater, test-retest reliability and construct validity of the PPDS? Methods This cross-sectional study included 56 children aged 1-18 years with central neurological diseases. Reliability was determined by the intraclass correlation coefficient (ICC). Validity was determined by Spearmans rho correlation, using the Functional Oral Intake Scale (FOIS) for children and, in case of cerebral palsy, complemented with the Eating and Drinking Ability Classification System (EDACS). Results A good intra- (ICC = 0.86, p < 0.01) and inter-rater reliability (ICC = 0.81, p < 0.01) was found. The test-retest reliability was poor (ICC = 0.01, p = 0.48). Construct validity showed a low, negative correlation with the FOIS (r = -0.34, p = 0.01) and a moderate, positive correlation with the EDACS (r = 0.67, p < 0.01). Conclusion This study was the first to apply the newly developed PPDS to a representative population-based sample. The good intra- and inter-rater reliability indicates that the PPDS can be used as pre-/post assessment for treatment of posterior drooling in clinical practice and future research. Recommendations A proposal for an adjusted PPDS and its protocol is made. Multiple testing with the PPDS is needed when diagnosing posterior drooling taking the low test-retest reliability into account.