Low language capacity in childhood: A systematic review of prevalence estimates.

BACKGROUND AND AIMS: Epidemiological studies have provided invaluable insight into the origin and impact of low language skills in childhood and adolescence. However, changing terminology and diagnostic guidelines have contributed to variable estimations of the prevalence of developmental language difficulties. The aim of this review was to profile the extent and variability of low language prevalence estimates through a systematic review of epidemiological literature. METHODS: A systematic review of the empirical research (August 2022) was undertaken to identify studies that aimed to estimate the prevalence of low language skills in children (<18 years). A total of 19 studies published between 1980-2022 met inclusion criteria for review. RESULTS: Studies reported prevalence estimates of low language skills in children between 1 and 16 years. Estimated rates varied from 0.4% to 25.2%. More stable estimations were observed in studies of children aged 5 years and older and those that applied updated diagnostic criteria to performance on standardised assessments of receptive and expressive language. CONCLUSIONS AND IMPLICATIONS: The estimated prevalence of low language skills in childhood varies considerably in the literature. Application of updated diagnostic criteria, including the assessment of functional impact, is critical to inform advocacy efforts and govern social, health and educational policies. WHAT THIS PAPER ADDS: What is already known on the subject Epidemiological research has informed our understanding of the origin and impact of low language capacity in childhood. Childhood language disorder is met with a rich history of evolving terminology and diagnostic guidelines to identify children with low language skills. Inconsistent definitions of and methods to identify low language in children have resulted in variable prevalence estimates in population-based studies. Variability in prevalence estimates impacts advocacy efforts to inform social, health and educational policy for child language disorder. What this study adds A total of 19 studies published at the time of this review aimed to provide estimates of the proportion of children who experience low language skills. Prevalence estimates varied between 0.4% and 25.2%, with more stable estimates reported in studies of older school-age children and those which utilised standardised assessments of both expressive and receptive language. Few studies utilised assessments of functional impact of language difficulties, which is misaligned with updated diagnostic criteria for child language disorder. What are the clinical implications of this work? This review reports substantial variability in estimates of the proportion of children and adolescents who live with low language skills. This variability underscores the importance of applying updated diagnostic criteria to identify the prevalence low language in childhood. Efforts to estimate the prevalence of low language must include measures of functional impact of low language skills. This aligns with clinical recommendations, which call for routine assessment of functional outcomes. To this end, we require a unified understanding of the term 'functional impact' in the context of low language, including the development and evaluation of measures that assess impact across emotional, social and academic domains.

Predictors of school concern across the transition to secondary school with developmental language disorder and low language ability: A longitudinal developmental cascade analysis.

BACKGROUND: Developmental language disorder (DLD) has clear functional ramifications in the areas of social competency, emotion recognition, emotional well-being and literacy skill, which have been found to persist from childhood to adolescence. These domains are important factors during the transition from primary to secondary school in typical development (TD). Nevertheless, there is a paucity of research on the transition from primary to secondary school for adolescents with DLD and low language (LL) ability. AIMS: To investigate the association between psychosocial domains, literacy skill and concerns about school during the transition to secondary school for adolescents with DLD, LL and their TD peers. The first research question examined whether levels of social competency, emotion recognition, emotional well-being and literacy skill predicted school concern for the three groups. The second research question explored the longitudinal relationship between school concern and psychosocial and literacy indicators over the transition. METHODS & PROCEDURES: Participants (aged 10-11 years) with DLD (n = 30), LL ((n = 29) and TD (n = 42) were recruited for this longitudinal study from eight UK primary schools. Standardized language and psychosocial assessments were administered in the spring and summer terms of the final year of primary school, and the autumn and summer terms of the first year in secondary school. OUTCOMES & RESULTS: Regression analyses showed pre-transition school concern to be predicted by emotion recognition for the DLD group, by social competence and emotional well-being for the LL group, and by social competence for the TD group. Post-transition concern was predicted by emotional well-being for the LL group; with no significant predictors for the DLD/TD groups. Path analyses revealed an association between literacy skill and emotion recognition for the DLD group. A developmental cascade illustrated a relationship between social competence and emotional well-being for the TD group. CONCLUSIONS & IMPLICATIONS: This study concludes that transition interventions must be differentiated according to language ability; support for DLD adolescents should focus on emotion recognition skill, provision for LL adolescents should centre on emotional well-being, and TD participants should be particularly supported in the domain of social competence in advance of the move to secondary school. Additionally, this study emphasizes the importance of the inclusion of a LL group, as their outcomes cannot be predicted using DLD/TD research. WHAT THIS PAPER ADDS: What is already known on the subject There is limited research exploring the transition from primary school to secondary for adolescents with DLD or LL ability. Research on TD has highlighted vulnerable domains at this time. As these key areas are evidenced spheres of difficulty in DLD and LL, there was a strong impetus for this study. What this paper adds to existing knowledge This study reveals differences between language ability groups in the predictors of school concern both pre- and post-transition. Concerns of adolescents with DLD were predicted by emotion recognition, those of adolescents with LL were predicted by emotional well-being, and a longitudinal link between social competence and emotional well-being was evidenced for TD adolescents. What are the potential or actual clinical implications of this work? This study has implications for researchers and clinicians, as a need has been identified for a new clinical group. It also has practical implications for transition support planning for educational practitioners, families and adolescents.

Health-related quality of life of caregivers of children with low language: Results from two Australian population-based studies.

Purpose: To examine (1) the association between low language (LL) and caregiver's health-related quality of life (HRQoL), (2) whether persistent LL affects caregiver's HRQoL and (3) whether child social-emotional-behavioural (SEB) difficulties attenuates the association between LL and caregiver's HRQoL.Method: Data were from the Early Language in Victoria Study (ELVS) and the Longitudinal Study of Australian Children (LSAC). Caregiver's HRQoL was measured using the EuroQoL-5 dimensions and the Assessment of Quality of Life-8 dimensions. Language ability was determined using the Clinical Evaluation of Language Fundamentals (CELF)-Preschool-2nd or 4th edition (ELVS) and the Peabody Picture Vocabulary Test-3rd edition or CELF-4 recalling sentences subscale (LSAC). Child SEB difficulties were measured using the Strengths and Difficulties Questionnaire. Multivariable linear regression was used for the analysis.Result: At 11-12 years, an association between LL and reduced caregiver's HRQoL was found in LSAC, but not in ELVS. Persistent LL from 4-11 years seemed to not affect caregivers' HRQoL in either cohort. Child SEB difficulties attenuated the association between caregiver's HRQoL and LL.Conclusion: Both LL and SEB difficulties contributed to reduced caregiver's HRQoL at children age 11-12 years. Interventions supporting children with LL should consider caregiver's well-being in provision of care that meets families' needs.

Consistency of Parental and Self-Reported Adolescent Wellbeing: Evidence From Developmental Language Disorder.

Research on adolescent wellbeing in Developmental Language Disorder (DLD) has previously been examined through measures of parent (proxy) or self-reported wellbeing, but never has a study included both and enabled comparison between the two. The current study reports parent and self rated wellbeing of adolescents with DLD and Low Language (LL) ability, as well as their typically developing (TD) peers. It also examines consistency between raters and factors influencing correspondence. Adolescents aged 10-11 with DLD (n = 30), LL (n = 29) or TD (n = 48) were recruited from eight UK primary schools. A battery of standardized language, psychosocial and wellbeing assessments, including the KIDSCREEN-27 were administered. Adolescent ratings of wellbeing were similar across groups on three of the five wellbeing dimensions, but those with DLD had lower self-reported Autonomy and Parental Relations than their TD peers, and both the DLD and LL group had lower School Environment scores than their TD peers. By parental report, the DLD and LL group were considered to have lower wellbeing on all five wellbeing dimensions relative to their TD peers. Paired sample t-test analyses indicated a high level of variance between parent and adolescent reported wellbeing for multiple wellbeing domains, especially Psychological Wellbeing. Importantly, predictors of the level of agreement between parent and adolescent reported psychological wellbeing differed between groups: cognitive reappraisal and sociability predicted this level of agreement for adolescents with LL, while social competence predicted agreement in DLD and TD. This study emphasizes the necessity of allowing adolescents of all language abilities to report their own wellbeing, as their perspective does not align with that of their parents. It also highlights the importance of including the full spectrum of need when investigating the impact of language ability on consistency between proxy and self-reported wellbeing.

Health-related quality of life of children with low language from early childhood to adolescence: results from an Australian longitudinal population-based study.

BACKGROUND: Low language abilities are known to be associated with significant adverse long-term outcomes. However, associations between low language and health-related quality of life (HRQoL) are unclear. We aimed to (a) examine the association between low language and HRQoL from 4 to 13 years and (b) classify the children's trajectories of HRQoL and language and examine the association between language and HRQoL trajectories. METHODS: Data were from an Australian community-based cohort of children. HRQoL was measured at ages 4-13 years using the parent-reported Pediatric Quality of Life Inventory 4.0. Language was assessed using the Clinical Evaluation of Language Fundamentals (CELF)-Preschool 2nd edition at 4 years and the CELF-4th edition at 5, 7 and 11 years. Multivariable linear regression and mixed effect modelling were used to estimate cross-sectional and longitudinal associations between low language and HRQoL from 4 to 13 years. A joint group-based trajectory model was used to characterize associations between HRQoL and language trajectories over childhood. RESULTS: Children with low language had substantially lower HRQoL than children with typical language from 4 to 13 years. Higher language scores were associated with better HRQoL, particularly in social and school functioning. Three HRQoL trajectories were identified: stable-high (51% of children), reduced with slow decline (40%) and low with rapid decline (9%). Children with low language were less likely to follow a stable-high HRQoL trajectory (40%) while 26% and 34% followed the reduced with slow decline and low with rapid decline trajectories, respectively. CONCLUSIONS: Children with low language experienced reduced HRQoL from 4 to 13 years. More than half had declining trajectories in HRQoL highlighting the need to monitor these children over time. Interventions should not only aim to improve children's language ability but also address the wider functional impacts of low language.

Health-Related Quality of Life in Children With Low Language or Congenital Hearing Loss, as Measured by the PedsQL and Health Utility Index Mark 3.

OBJECTIVES: To examine health-related quality of life (HRQoL) in young children with low language or congenital hearing loss and to explore the value of assessing HRQoL by concurrently administering 2 HRQoL instruments in populations of children. METHODS: Data were from 2 Australian community-based studies: Language for Learning (children with typical and low language at age 4 years, n = 1012) and the Statewide Comparison of Outcomes study (children with hearing loss, n = 108). HRQoL was measured using the parent-reported Health Utilities Index Mark 3 (HUI3) and the Pediatrics Quality of Life Inventory 4.0 (PedsQL) generic core scale. Agreement between the HRQoL instruments was assessed using intraclass correlation and Bland-Altman plots. RESULTS: Children with low language and with hearing loss had lower HRQoL than children with normal language; the worst HRQoL was experienced by children with both. The lower HRQoL was mainly due to impaired school functioning (PedsQL) and speech and cognition (HUI3). Children with hearing loss also had impaired physical and social functioning (PedsQL), vision, hearing, dexterity, and ambulation (HUI3). Correlations between instruments were poor to moderate, with low agreement. CONCLUSIONS: Children with low language and congenital hearing loss might benefit from interventions targeting overall health and well-being, not just their impairments. The HUI3 and PedsQL each seemed to provide unique information and thus may supplement each other in assessing HRQoL of young children, including those with low language or congenital hearing loss.

Health-related quality of life, service utilization and costs of low language: A systematic review.

BACKGROUND: Low language (LL) is a common childhood condition affecting 7-17% of children. It is associated with life-long adverse outcomes and can affect various aspects of a child's life. However, the literature on its impact on health-related quality of life (HRQoL), service use and costs are limited. To date, there has been no systematic review of the overall economic burden of LL. A systematic review regarding the economic burden of LL is important for clinical, educational, policy decision-making and theoretical aspects. We adopted the term 'low language' to refer to children whose language performance falls below well-recognized cut-points regardless of known or unknown aetiology. AIMS: To review the literature systematically on how LL is associated with HRQoL, service utilization and costs. METHODS & PROCEDURES: A systematic search was conducted across various databases, including MEDLINE, Embase, PsycINFO, CINAHL, up to July 2017. Data on study design, population and outcomes were extracted and screened by two pairs of reviewers with the revision of other experts in the panel on any discrepancies. The Effective Public Health Practice Project tool was used to assess the risk of bias of the included studies. The findings of the included studies were summarized in a narrative synthesis. OUTCOMES & RESULTS: We identified 22 relevant articles, of which 12 reported HRQoL and 11 reported service utilization and costs associated with LL. Preference-based instruments, which include the relative importance attached to different aspects of HRQoL, were less employed in the literature. Most studies found poorer HRQoL in children with LL compared with their peers. About half the families having children with LL did not actively seek professional help, and many families felt they did not receive sufficient services when needed. Healthcare costs associated with LL were substantial. Non-healthcare costs were largely unexplored. CONCLUSIONS & IMPLICATIONS: LL was associated with reduced children's HRQoL, higher service use and costs. Under-servicing was evident in children with LL. LL also imposed large costs on the healthcare system. Further research is required to examine (1) the overall HRQoL of children with LL, in particular studies using and testing the performance of preference-based instruments; and (2) the service use and costs specific to LL, especially non-healthcare costs.

Expectations of the transition to secondary school in children with developmental language disorder and low language ability.

BACKGROUND: A successful transition from primary to secondary school for typically developing (TD) children is associated with academic and psychosocial outcomes. Children with developmental language disorder (DLD) tend to have pervasive needs in both of these domains, yet little is known about their experience of this transition. We have no information concerning the transition for children with low language (LL). AIM: (1) To explore the expectations of the transition to primary school for children with DLD, children with LL proficiency, and their TD peers; (2) to examine the predictors of transition concerns for each group. SAMPLE: Children aged 10-11 in the final year of primary school with DLD (n = 30), LL (n = 29), or TD (n = 48) were recruited from eight UK primary schools in the summer term. METHODS: A battery of standardized language and psychosocial assessments, including the School Concerns Questionnaire (SCQ; Rice et al. British Journal of Educational Psychology, 81, 2011, 244), was administered. RESULTS: The TD group had significantly lower levels of school concern than DLD and LL groups while DLD and LL groups did not significantly differ. Scholastic competence predicted overall concerns of children with DLD; social competence predicted TD overall concerns; and no variables predicted overall concerns of children with LL. Exploration of school concern subfactors highlighted the importance of emotion recognition for all groups and social competence for children with LL. CONCLUSIONS: Results indicate that school provision to facilitate a successful transition may most usefully target different areas depending on pupils' language level.

Spanish-English Bilingual Children's Relative Use of English Tense and Agreement Morphemes.

Best practice for bilingual speakers involves considering performance in each language the client uses. To support this practice for young clients, a comprehensive understanding of how bilingual children develop skills in each language is needed. To that end, the present work investigates relative use of English tense and agreement (T/A) morphemes - a skill frequently considered as part of a complete language assessment - in Spanish-English developing bilingual preschoolers with varying levels of language ability. Results indicate that developing bilingual children with both typical and weak language skills demonstrate greater use of copula and auxiliary BE relative to third person singular, past tense and auxiliary DO. Findings thus reveal a relative ranking of T/A morphemes in developing bilingual children that differs from that of English monolingual children, who demonstrate relatively later emergence and productivity of auxiliary BE. In turn, findings demonstrate the importance of utilizing appropriate comparisons in clinical practice.

Late talkers and later language outcomes: Predicting the different language trajectories.

PURPOSE: The aim of the current study was to investigate the risk factors present at 2 years for children who showed language difficulties that persisted from 2 to 10 years and difficulties that emerged later, at 10 years. METHOD: Participants (n = 783) were drawn from the Raine Study in Western Australia. Patterns of change from 2 to 10 years were identified based on child performance on the Language Development Survey and the Clinical Evaluation of Language Fundamentals, respectively. Logistic regression analyses were conducted to test whether parental, family and child characteristics present at 2 years predicted poorer language outcomes at age 10. RESULT: Across the 8 year period, 5.6% of the children displayed consistently low language skills, 5.9% improved skills and 23.2% deteriorated skills. Compared to children with consistently typical skills, the deteriorated group was more likely to have mothers who smoked during pregnancy, fathers with incomplete secondary education, low family income, poor early literacy environment and be male. Children showing consistently low language skills were more likely to have mothers who smoked during pregnancy than late talkers whose early delays improved. CONCLUSION: Results provide evidence of some modifiable risk factors at 2 years which are associated with language outcome.