Accurate assessment of drooling severity with the 5-minute drooling quotient in children with developmental disabilities

The aims of this study were to examine whether objective measurements of the 10-minute drooling quotient (DQ10) and the 5-minute drooling quotient (DQ5) are interchangeable; to assess agreement between the measurements and their accuracy in classifying drooling severity; and to develop a time-efficient clinical assessment.

The study cohort included 162 children (61 females, 101 males; mean age 11 y 6 mo, SD 4 y 5 mo, range 3 y 9 mo-22 y 1 mo) suffering from moderate to profuse drooling. One hundred and twenty-four had cerebral palsy and 38 had other developmental disabilities. Seventy-four of the participants were ambulant and 88 non-ambulant. The original DQ10 was recalculated into a 5-minute score (DQ5). Assessments were undertaken while the participants were in a rest situation (DQ(R)) and while they were active (DQ(A)). Agreement in scores was quantified using intraclass correlations and Bland-Altman plots. To classify drooling, area under the receiver operating characteristic curve analysis was used to compare accuracy of the DQ10 and DQ5 at rest and during activity.

Agreement between DQ10A, and DQ5(A), and between DQ10(R) and DQ5(R) was high (intraclass correlation coefficient >0.90). Moderate agreement existed between DQ(A) and DQ(R). DQ(A) scores were more accurate in classifying children's drooling behaviour. For DQ5(A), a cut-off point of 18 or more (drooling episodes/observation time) might indicate 'constant drooling'.

The DQ10 and DQ5 can be used interchangeably. DQ(A) is most discriminative for drooling severity. For evaluating treatment efficiency the cut-off point can be used. For clinical and research purposes, the DQ5 is time efficient and cost saving while validity, and intrarater and interrater reliability are preserved.