High-intensity vs Low-intensity Speech Intervention in Children With Phonological Speech Sound Disorders

Consonant proficiency will be measured in terms of percentage correctly produced consonants (%)

The cost-utility of the high intensity speech intervention compared to the low intensity speech intervention will be examined by calculating the ratio of the incremental costs to the incremental health effects (QALYs) called the incremental cost-utility ratio (ICUR), calculated as Cost intervention - Cost control / Effect intervention - Effect control. The EQ-5D-Youth version will be used for children aged 8-12 years and the EQ-5D proxy version for children aged 4-7 years to collect information on HRQoL ("utilities"). Cost information will be obtained using a self-reported questionnaire on health care use.

The cost-effectiveness of the high intensity speech intervention compared to the low intensity speech intervention will be examined by calculating the ratio of the incremental costs to the incremental health effects (percentage correctly produced consonants) called the incremental cost-effectiveness ratio (ICER), calculated as Cost intervention - Cost control / Effect intervention - Effect control. The effectiveness will be estimated using the primary outcome (percentage correctly produced consonants) obtained from the randomized controlled trial. Cost information will be obtained using a self-reported questionnaire on health care use.

To assess possible transfer of learned speech skills to contexts outside the therapy setting, the Intelligibility in Context Scale (ICS) will be administered. The ICS rates the degree to which children's speech is understood by different partners (caregivers, immediate and extended family, friends, acquaintances, teachers, and strangers) on a 5-point scale (1 - never intelligible to 5 - always intelligible) with a minimum score of 7 and a maximum score of 35. The higher the score, the better the result.

To evaluate the change in communication attitudes of children aged 4 and 5 years during the intervention, the KiddyCAT will be administered before, during and after the intervention. This questionnaire evaluates the extent to which the child has a negative attitude toward speaking. The higher the score, the more negative the attitude toward speaking. the scores range from 0 (no negative communication attitudes) to 14 (negative communication attitudes only).

To evaluate the change in communication attitudes of children aged 6 years and older during the intervention, the Communication Attitudes Test (CAT) will be administered before, during and after the intervention. This questionnaire evaluate the extent to which the child has a negative attitude toward speaking. The higher the score, the more negative the attitude toward speaking. the scores range from 0 (no negative communication attitudes) to 33 (negative communication attitudes only).

The instrument targets two hierarchical levels of phonological awareness and consists of 6 subtests of 4 test items. Minimum raw score is 0 and maximum possible score is 24, with higher scores reflecting better phonological awareness skills.

The instrument targets three hierarchical levels of phonological awareness and consists of four subtests of 10 test items. Children are asked to rhyme, to segment words in syllables, to combine phonemes into words and the repeat non-words. Minimum raw score is 0 and maximum possible score is 40, with higher scores reflecting better phonological awareness skills.