OBJECTIVE: To quantify the contributions of child, family, and environmental predictors to language ability at 4 years.METHODS: A longitudinal study was performed with a sample of 1910 infants recruited at 8 months in Melbourne, Australia. Predictors were child gender, prematurity, birth weight and order, multiple birth, socioeconomic status, maternal mental health, vocabulary, education, and age at child's birth, non–English-speaking background, and family history of speech/language difficulties. Outcomes were Clinical Evaluation of Language Fundamentals-Preschool, language scores, low language status (scores >1.25 SDs below the mean), and specific language impairment (SLI) (scores >1.25 SDs below the mean for children with normal nonverbal performance).RESULTS: A total of 1596 children provided outcome data. Twelve baseline predictors explained 18.9% and 20.9% of the variation in receptive and expressive scores, respectively, increasing to 23.6% and 30.4% with the addition of late talking status at age 2. A total of 20.6% of children (324 of 1573 children) met the criteria for low language status and 17.2% (251 of 1462 children) for SLI. Family history of speech/language problems and low maternal education levels and socioeconomic status predicted adverse language outcomes. The combined predictors discriminated only moderately between children with and without low language levels or SLIs (area under the curve: 0.72–0.76); this improved with the addition of late talking status (area under the curve: 0.78–0.84).CONCLUSIONS: Measures of social disadvantage helped explain more variation in outcomes at 4 years than at 2 years, but ability to predict low language status and SLI status remained limited.

Background: The term ‘specific language impairment’ (SLI), in use since the 1980s, describes children with language impairment whose cognitive skills are within normal limits where there is no identifiable reason for the language impairment. SLI is determined by applying exclusionary criteria, so that it is defined by what it is not rather than by what it is. The recent decision to not include SLI in DSM‐5 provoked much debate and concern from researchers and clinicians.Aims: To explore how the term ‘specific language impairment’ emerged, to consider how disorders, including SLI, are generally defined and to explore how societal changes might impact on use the term.Methods & Procedures: We reviewed the literature to explore the origins of the term ‘specific language impairment’ and present published evidence, as well as new analyses of population data, to explore the validity of continuing to use the term.Outcomes & Results and Conclusions & Implications: We support the decision to exclude the term ‘specific language impairment’ from DSM‐5 and conclude that the term has been a convenient label for researchers, but that the current classification is unacceptably arbitrary. Furthermore, we argue there is no empirical evidence to support the continued use of the term SLI and limited evidence that it has provided any real benefits for children and their families. In fact, the term may be disadvantageous to some due to the use of exclusionary criteria to determine eligibility for and access to speech pathology services. We propose the following recommendations. First, that the word ‘specific’ be removed and the label ‘language impairment’ be used. Second, that the exclusionary criteria be relaxed and in their place inclusionary criteria be adopted that take into account the fluid nature of language development particularly in the preschool period. Building on the goodwill and collaborations between the clinical and research communities we propose the establishment of an international consensus panel to develop an agreed definition and set of criteria for language impairment. Given the rich data now available in population studies it is possible to test the validity of these definitions and criteria. Consultation with service users and policy‐makers should be incorporated into the decision‐making process.

Aim: The epidemiology of preschool speech sound disorder is poorly understood. Our aims were to determine: the prevalence of idiopathic speech sound disorder; the comorbidity of speech sound disorder with language and pre‐literacy difficulties; and the factors contributing to speech outcome at 4 years.Method: One thousand four hundred and ninety‐four participants from an Australian longitudinal cohort completed speech, language, and pre‐literacy assessments at 4 years. Prevalence of speech sound disorder (SSD) was defined by standard score performance of ≤79 on a speech assessment. Logistic regression examined predictors of SSD within four domains: child and family; parent‐reported speech; cognitive‐linguistic; and parent‐reported motor skills.Results: At 4 years the prevalence of speech disorder in an Australian cohort was 3.4%. Comorbidity with SSD was 40.8% for language disorder and 20.8% for poor pre‐literacy skills. Sex, maternal vocabulary, socio‐economic status, and family history of speech and language difficulties predicted SSD, as did 2‐year speech, language, and motor skills. Together these variables provided good discrimination of SSD (area under the curve=0.78).Interpretation: This is the first epidemiological study to demonstrate prevalence of SSD at 4 years of age that was consistent with previous clinical studies. Early detection of SSD at 4 years should focus on family variables and speech, language, and motor skills measured at 2 years.

OBJECTIVE. This article responds to evidence gaps regarding language impairment identified by the US Preventive Services Task Force in 2006. We examine the contributions of putative child, family, and environmental risk factors to language outcomes at 24 months of age. METHODS. A community-ascertained sample of 1720 infants who were recruited at 8 months of age were followed at ages 12 and 24 months in a prospective, longitudinal study in metropolitan Melbourne, Australia. Outcomes at 24 months were parent-reported infant communication (Communication and Symbolic Behavior Scales and MacArthur-Bates Communicative Development Inventories vocabulary production score). Putative risk factors were gender, preterm birth, birth weight, multiple birth, birth order, socioeconomic status, maternal mental health, maternal vocabulary and education, maternal age at birth of child, non–English-speaking background, and family history of speech-language difficulties. Linear regression models were fitted to total standardized Communication and Symbolic Behavior Scales and Communicative Development Inventories vocabulary production scores; a logistic regression model was fitted to late-talking status at 24 months. RESULTS. The regression models accounted for 4.3% and 7.0% of the variation in the 24-month Communication and Symbolic Behavior Scales and Communicative Development Inventories scores, respectively. Male gender and family history were strongly associated with poorer outcomes on both instruments. Lower Communication and Symbolic Behavior Scales scores were also associated with lower maternal vocabulary and older maternal age. Lower vocabulary production scores were associated with birth order and non–English-speaking background. When the 12-month Communication and Symbolic Behavior Scales Total score was added as a covariate in the linear regression of 24-month Communication and Symbolic Behavior Scales Total score, it was by far the strongest predictor. CONCLUSIONS. These early risk factors explained no more than 7% of the variation in language at 24 months. They seem unlikely to be helpful in screening for early language delay.

OBJECTIVES. Our goals were to document (1) the onset of stuttering and (2) whether specific child, family, or environmental factors predict stuttering onset in children aged up to 3 years. METHODS. Participants included a community-ascertained cohort of 1619 2-year-old Australian children recruited at 8 months of age to study the longitudinal development of early language. The main outcome measure was parental telephone report of stuttering onset, verified by face-to-face expert diagnosis. Preonset continuous measures of the child's temperament (approach/withdrawal) and language development were available. Information on a range of predictor measures hypothesized to be associated with stuttering onset was obtained (maternal mental health and education levels, gender, premature birth status, birth weight, birth order, twinning, socioeconomic status, family history of stuttering). RESULTS. By 3 years of age, the cumulative incidence of stuttering onset was 8.5%. Onset often occurred suddenly over 1 to 3 days (49.6%) and involved the use of word combinations (97.1%). Children who stuttered were not more shy or withdrawn. Male gender, twin birth status, higher vocabulary scores at 2 years of age, and high maternal education were associated with stuttering onset. The multivariable model, however, had low predictive strength; just 3.7% of the total variation in stuttering onset was accounted for. CONCLUSIONS. The cumulative incidence of stuttering onset was much higher than reported previously. The hypothesized risk factors for stuttering onset together explained little of the variation in stuttering onset up to 3 years of age. Early onset was not associated with language delay, social and environmental factors, or preonset shyness/withdrawal. Health professionals can reassure parents that onset is not unusual up to 3 years of age and seems to be associated with rapid growth in language development.