Speech TherapyNCT07779759
High-intensity vs Low-intensity Speech Intervention in Children With Phonological Speech Sound Disorders
A study testing High-intensity combined phonetic-phonological intervention and Low-intensity combined phonetic-phonological intervention in people with Speech Therapy and Speech Disorders in Children, run by University Ghent at 1 site in Belgium.
Trial summary
Achieving speech that is understandable and acceptable to others is the key outcome in the treatment of phonological speech sound disorders. Therefore, speech therapy provided by a speech-language pathologist is essential. Read more about this study
- Who is it for?
- Ages 4 to 12 years
- Conditions the study is for
- Speech Therapy, Speech Disorders in Children, Phonological (Speech) Disorder
- What is being tested?
- High-intensity combined phonetic-phonological intervention and Low-intensity combined phonetic-phonological intervention
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 1 siteBelgium
- Study dates
- 30 Nov 2025to 30 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 4 to 12 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Age between 4 and 12 years
- Presence of at least one phonological speech sound disorder.
Who cannot join
- Presence of a language disorder
- Presence of hearing disorders
- Presence of neurological or neuromuscular disorders
- Presence of craniofacial anomalies (e.g., a cleft palate)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
University Hospital Ghent
Ghent, 9000
Kristiane Van Lierde, +3293320530, hiruz.ctu@uzgent.be
About this study
Official title: The Short- and Long-Term Effects and Cost-Effectiveness of High-Intensity Versus Low-Intensity Speech Intervention in Children With Phonological Speech Sound Disorders.
Achieving speech that is understandable and acceptable to others is the key outcome in the treatment of phonological speech sound disorders. Therefore, speech therapy provided by a speech-language pathologist is essential. Traditionally, this intervention has been delivered twice per week for 30 minutes, often over the course of several months or even years, by first-line speech-language pathologists. Unfortunately, this low-intensity approach is largely based on historical practice rather than scientific evidence.
The current study aims to provide stronger evidence regarding the optimal intensity of intervention. Specifically, this project will compare the effects of high-intensity and low-intensity speech intervention in children with phonological speech sound disorders in terms of speech outcomes, quality of life, and cost-utility. The interventions will be provided by first-line speech-language pathologists within a large-scale randomized controlled trial. The ultimate goal is to implement this program in clinical practice and raise awareness among stakeholders about its benefits for children with phonological speech sound disorders
- Being tested
- High-intensity combined phonetic-phonological intervention, Low-intensity combined phonetic-phonological intervention
- Keywords
- Speech Therapy, Randomized Controlled Trial, Children with Speech Sound Disorders, Cost-effectiveness
- Medical subject headings
- Communication Disorders, Articulation Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High-intensity combined phonetic-phonological interventionBehavioural
Children will receive phonological speech therapy supplemented by phonetic principles. A next level will be introduced when the child is able to correctly produce the sound in 80% of the time with minimal cues from the therapist. Multiple errors will be targeted simultaneously by focusing on a process. Child-friendly games will be played to illustrate the contrast between concepts. Exercises will be embedded in meaningful language contexts such as minimal pairs. Therapy will be provided 5 times 30' per week for 2 times 2 weeks.
Low-intensity combined phonetic-phonological interventionBehavioural
Children will receive phonological speech therapy supplemented by phonetic principles. A next level will be introduced when the child is able to correctly produce the sound in 80% of the time with minimal cues from the therapist. Multiple errors will be targeted simultaneously by focusing on a process. Child-friendly games will be played to illustrate the contrast between concepts. Exercises will be embedded in meaningful language contexts such as minimal pairs. Therapy will be provided 5 times 30' per week for 10 consecutive weeks.
| Study group | Role | What they receive |
|---|---|---|
| High-intensity Speech Intervention | Experimental | To investigate the (cost-)effectiveness of speech therapy for children with phonological speech sound disorders, a community based SLP will provide a high-intensity speech intervention. Receives: Behavioral: High-intensity combined phonetic-phonological intervention |
| Low-intensity Speech Intervention | Active comparator | To investigate the (cost-)effectiveness of speech therapy for children with phonological speech sound disorders, a community based SLP will provide a low-intensity speech intervention. Receives: Behavioral: Low-intensity combined phonetic-phonological intervention |
What is being measured
The primary outcome is the main question the study is designed to answer.
Consonant proficiency (percentage correctly produced consonants)
Consonant proficiency will be measured in terms of percentage correctly produced consonants (%)
Measured: Assessment 2 weeks pre-intervention, immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 2 weeks post-intervention, at 12 weeks post-intervention
Incremental cost-utility ratio
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.
Measured: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
Incremental cost-effectiveness ratio
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.
Measured: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
Secondary outcomes (5)
Intelligibility in Context Scale (ICS)
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.
Measured: Assessment 2 weeks pre-intervention, immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 2 weeks post-intervention, at 12 weeks post-intervention
Communication attitudes of children aged 4 and 5 years (KiddyCAT)
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).
Measured: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
Communication attitudes Test (CAT)
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).
Measured: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
Phonological Awareness subtest from the CELF-Preschool-II-NL
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.
Measured: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
Dutch Phonological Awareness Test (Proef Fonologisch Bewustzijn)
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.
Measured: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Aug 2026
- Study start30 Nov 2025
- Primary completion30 Dec 2027 (estimated)
- Study completion30 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Speech TherapyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Ghent
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Kristiane Van Lierde, Principal investigator, University Ghent
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07779759
- Sponsor's protocol ID
- ONZ-2025-0439
- Status last verified
- Aug 2026
- First submitted
- 14 Nov 2025
- Last updated
- 21 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Short- and Long-Term Effects and Cost-Effectiveness of High-Intensity Versus Low-Intensity Speech Intervention in Children With Phonological Speech Sound Disorders.
- ClinicalTrials.gov ID
- NCT07779759
- Acronym / sponsor ID
- ONZ-2025-0439
- Keywords
- Speech Therapy, Randomized Controlled Trial, Children with Speech Sound Disorders, Cost-effectiveness
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- University GhentUniversity, hospital or other
- Study start
- 30 Nov 2025 (actual)
- Primary completion
- 30 Dec 2027 (estimated)
- Study completion
- 30 Dec 2027 (estimated)
- First posted
- 21 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Achieving speech that is understandable and acceptable to others is the key outcome in the treatment of phonological speech sound disorders. Therefore, speech therapy provided by a speech-language pathologist is essential. Traditionally, this intervention has been delivered twice per week for 30 minutes, often over the course of several months or even years, by first-line speech-language pathologists. Unfortunately, this low-intensity approach is largely based on historical practice rather than scientific evidence.
The current study aims to provide stronger evidence regarding the optimal intensity of intervention. Specifically, this project will compare the effects of high-intensity and low-intensity speech intervention in children with phonological speech sound disorders in terms of speech outcomes, quality of life, and cost-utility. The interventions will be provided by first-line speech-language pathologists within a large-scale randomized controlled trial. The ultimate goal is to implement this program in clinical practice and raise awareness among stakeholders about its benefits for children with phonological speech sound disorders
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| High-intensity Speech Intervention | Experimental | Behavioral: High-intensity combined phonetic-phonological interventionTo investigate the (cost-)effectiveness of speech therapy for children with phonological speech sound disorders, a community based SLP will provide a high-intensity speech intervention. |
| Low-intensity Speech Intervention | Active comparator | Behavioral: Low-intensity combined phonetic-phonological interventionTo investigate the (cost-)effectiveness of speech therapy for children with phonological speech sound disorders, a community based SLP will provide a low-intensity speech intervention. |
Who may qualify
- Ages
- 4 to 12 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (2 listed)
- Age between 4 and 12 years
- Presence of at least one phonological speech sound disorder.
Key exclusion criteria (4 listed)
- Presence of a language disorder
- Presence of hearing disorders
- Presence of neurological or neuromuscular disorders
- Presence of craniofacial anomalies (e.g., a cleft palate)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| High-intensity combined phonetic-phonological interventionChildren will receive phonological speech therapy supplemented by phonetic principles. A next level will be introduced when the child is able to correctly produce the sound in 80% of the time with minimal cues from the therapist. Multiple errors will be targeted simultaneously by focusing on a process. Child-friendly games will be played to illustrate the contrast between concepts. Exercises will be embedded in meaningful language contexts such as minimal pairs. Therapy will be provided 5 times 30' per week for 2 times 2 weeks. | Behavioural | High-intensity Speech Intervention |
| Low-intensity combined phonetic-phonological interventionChildren will receive phonological speech therapy supplemented by phonetic principles. A next level will be introduced when the child is able to correctly produce the sound in 80% of the time with minimal cues from the therapist. Multiple errors will be targeted simultaneously by focusing on a process. Child-friendly games will be played to illustrate the contrast between concepts. Exercises will be embedded in meaningful language contexts such as minimal pairs. Therapy will be provided 5 times 30' per week for 10 consecutive weeks. | Behavioural | Low-intensity Speech Intervention |
Primary outcome
Consonant proficiency (percentage correctly produced consonants)
Time frame: Assessment 2 weeks pre-intervention, immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 2 weeks post-intervention, at 12 weeks post-intervention
Consonant proficiency will be measured in terms of percentage correctly produced consonants (%)
Incremental cost-utility ratio
Time frame: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
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.
Incremental cost-effectiveness ratio
Time frame: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
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.
5 secondary outcomes
Intelligibility in Context Scale (ICS)
Time frame: Assessment 2 weeks pre-intervention, immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 2 weeks post-intervention, at 12 weeks post-intervention
Communication attitudes of children aged 4 and 5 years (KiddyCAT)
Time frame: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
Communication attitudes Test (CAT)
Time frame: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
Phonological Awareness subtest from the CELF-Preschool-II-NL
Time frame: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
Dutch Phonological Awareness Test (Proef Fonologisch Bewustzijn)
Time frame: Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Kristiane Van Lierde principal investigator
University Ghent
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High-intensity combined phonetic-phonological intervention and Low-intensity combined phonetic-phonological intervention in people with Speech Therapy and Speech Disorders in Children, run by University Ghent at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 21 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Fien Allemeersch (+32474128135, fien.allemeersch@ugent.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Consonant proficiency (percentage correctly produced consonants) (time frame: Assessment 2 weeks pre-intervention, immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 2 weeks post-intervention, at 12 weeks post-intervention). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Aug 2026.