Corrigendum: Stuttering in individuals with Down syndrome: a systematic review of earlier research.

[This corrects the article DOI: 10.3389/fpsyg.2023.1176743.].

Stuttering in individuals with Down syndrome: a systematic review of earlier research.

The main objective of this systematic review was to synthesize the evidence on the occurrence and characteristics of stuttering in individuals with Down syndrome and thus contribute knowledge about stuttering in this population. Group studies reporting outcome measures of stuttering were included. Studies with participants who were preselected based on their fluency status were excluded. We searched the Eric, PsychInfo, Medline, Scopus, and Web of Science Core Collection databases on 3rd January 2022 and conducted supplementary searches of the reference lists of previous reviews and the studies included in the current review, as well as relevant speech and language journals. The included studies were coded in terms of information concerning sample characteristics, measurement approaches, and stuttering-related outcomes. The appraisal tool for cross-sectional studies (AXIS) was used to evaluate study quality. We identified 14 eligible studies, with a total of 1,833 participants (mean = 131.29, standard deviation = 227.85, median = 45.5) between 3 and 58 years of age. The estimated occurrence of stuttering ranged from 2.38 to 56%, which is substantially higher than the estimated prevalence (1%) of stuttering in the general population. The results also showed that stuttering severity most often was judged to be mild-to-moderate and that individuals with Down syndrome displayed secondary behaviors when these were measured. However, little attention has been paid to investigating the potential adverse effects of stuttering for individuals with Down syndrome. We judged the quality of the evidence to be moderate-to-low. The negative evaluation was mostly due to sampling limitations that decreased the representability and generalizability of the results. Based on the high occurrence of stuttering and the potential negative effects of this condition, individuals with Down syndrome who show signs of stuttering should be referred to a speech and language pathologist for an evaluation of their need for stuttering treatment.

Stuttering Behavior in a National Age Cohort of Norwegian First-Graders With Down Syndrome.

PURPOSE: The aims of this study were to investigate the occurrence of stuttering behavior across time and to evaluate the relationship between stuttering behavior and language ability in children with Down syndrome. METHOD: A national age cohort of Norwegian first graders with Down syndrome (N = 75) participated in the study. Speech samples from a story-retelling task and a picture book dialogue as well as standardized measures of vocabulary, grammar, and nonverbal mental ability were collected at two time points approximately 5 months apart. Stuttering behavior was evaluated through counting stuttering-like disfluencies and stuttering severity ratings. The relationship between stuttering behavior and language ability was investigated through hierarchical regression analysis. RESULTS: The participants had stuttering severity ratings ranging from no stuttering behavior to severe and displayed all types of stuttering-like disfluencies. There were significant relationships between stuttering behavior and language ability at the first time point, whereas the relationships were not significant at the second time point. The stuttering severity ratings were significantly predicted by language ability across time, whereas the frequency of stuttering-like disfluencies was not. CONCLUSIONS: The occurrence of stuttering behavior was high across the measures and time points; however, the relationship between stuttering behavior and language ability varied across these variables. Thus, the nature of the relationship does not seem to follow a strict pattern that can be generalized to all children across time.

Children with Down syndrome can benefit from language interventions; Results from a systematic review and meta-analysis.

Language disorder is a cardinal challenge for children with Down syndrome, and their learning capacity has been debated. The aim of the current study was to conduct a systematic review and meta-analysis of existing language interventions for children with Down syndrome to reveal knowledge about the effects of these interventions and identify any common characteristics specific to effective or ineffective interventions. A systematic search was conducted in databases relevant for education, speech and language therapy, and psychology. Based on a set of predefined inclusion criteria, the hits were screened and coded. Eight studies were synthesised in a systematic review and four in a meta-analysis. The overall effect of the interventions was large (g = 1.01), but significant transfer effects to untrained aspects of language were rarely found. Interventions showing significant effects varied with regards to numerous characteristics including the age of the target group, the intervention approach, the dosage, and the implementer. The common characteristic across the effective interventions was simply the aim of improving language skills in children with Down syndrome. Overall, there was a moderate to high risk of bias across all studies. To conclude, children with Down syndrome have the potential to respond to language intervention. However, more interventions that reach transfer effects are needed to maximise children's language outcomes. Based on the limited number of studies and a moderate to high risk of bias across the studies, there is a great need for more robust intervention studies to ensure that future interventions are informed by high-quality research.