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

August 18, 2026 updated by: University Ghent

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

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
80

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Belgium
      • Ghent, Belgium, 9000
        • Recruiting
        • University Hospital Ghent
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age between 4 and 12 years
  • Presence of at least one phonological speech sound disorder.

Exclusion Criteria:

  • Presence of a language disorder
  • Presence of hearing disorders
  • Presence of neurological or neuromuscular disorders
  • Presence of craniofacial anomalies (e.g., a cleft palate)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: High-intensity Speech Intervention
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.
Behavioral: High-intensity combined phonetic-phonological intervention
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.
Active Comparator: Low-intensity Speech Intervention
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.
Behavioral: Low-intensity combined phonetic-phonological intervention
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.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
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 (%)
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
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.
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
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.
Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
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
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.
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
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).
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
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).
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
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.
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
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.
Assessment immediately pre-intervention, after 5 hours of therapy, after a 6-week rest period, immediately post-intervention, at 12 weeks post-intervention

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Ghent

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Kristiane Van Lierde, University Ghent

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 30, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 14, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 18, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 21, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 21, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 18, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ONZ-2025-0439

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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