Study registration
Chapter 1 Introduction and programme overview Introduction
The focus of this research programme, known as Child Talk, is on speech and language therapist (SLT)-led interventions for preschool children with primary speech and language impairment (PSLI).
Primary speech and language impairment
Primary speech and language impairment is a relatively stable, high-prevalence condition that can persist into adolescence and adulthood and which is associated with a range of negative sequelae. Children with PSLI present with delayed speech and language, which is not associated with any other overt congenital, developmental, neurological or sensory disorders. However, the way that the impairment manifests in any individual varies considerably. Over the years, various terms have been used to refer to this impairment, the most common being specific language impairment. Currently, the Raise Awareness of Language Learning Impairments (RALLI) campaign is promoting awareness of specific language impairment and
generating a discussion about agreeing consistency of terminology to avoid confusion.1The impairment
can be particularly difficult to diagnose during the preschool years because of the wide range of what is
considered to be‘typical development’ in both language and cognition and the absence of conclusive
research on the predictors of resolution. Nonetheless, delays that involve only expressive language,
the so-called‘late talkers’, are more likely to resolve before children reach school than difficulties in both
receptive and expressive language skills.2–5
Adult concern begins to consolidate at around the age of 2 years when around 50% of children will be
joining words into short phrases and sentences.6,7Those considered to be‘late talkers’ at this age will
typically have a vocabulary of< 50 words and will not be joining words.8Some children may also find it
hard to learn new word meanings, have difficulties understanding what is said to them or show other cognitive difficulties such as problems with attention, symbolic development and memory, despite other aspects of their development proceeding normally. Children who have difficulty with understanding language are thought to have difficulties that are less likely to resolve.9
The majority of those children whose language is delayed at 2 years will go on to develop functional speech and language, for example they will be able to communicate their needs in everyday situations and be intelligible to strangers. However, they are more likely to have life-long difficulties with language and language-related activities, such as understanding more abstract and inferential language, literacy, social
interactions and friendships.10–16Prevalence estimates vary, but an accepted rate of PSLI at 6 years is
around 7.4%.17,18This is higher than for autism, for which a prevalence of 1% is commonly accepted,19,20
and for cleft palate, for which 1 in 700 births is a typically quoted figure.21,22
Speech and language therapy
Speech and language therapy is the lead profession responsible for diagnosing and managing interventions for these children. This process typically takes place in collaboration with parents, early years practitioners (EYPs), psychologists, paediatricians and health visitors. For this preschool population, speech and language therapy services are primarily funded through the NHS, although there are increasing numbers of SLTs being funded into public health roles by the early years department of local authorities and, for older children, by individual schools.
Preschool children considered at risk for PSLI are typically, and most commonly, identified by EYPs, health visitors and parents themselves and are then referred to speech and language therapy services. Services
may be delivered in a range of settings: community clinics, children’s centres, nursery classes and schools
Council23and it is estimated that approximately 70% of these work with children.24There are, however, no national data on the number who work specifically with preschool children or indeed on the spread of pay grades and expertise or the numbers who work with children with different speech and language conditions. A survey by the Royal College of Speech and Language Therapists (RCSLT) is currently under
way to help gather some of this information.25
The process of supporting children with PSLI has changed over the years. Several decades ago the approach was primarily focused on the child. Children were typically brought to a clinic by their parents and, following assessment and identification of the possibility of language impairment, the SLT would carry out interventions directly with the child. Sometimes the parent would observe the SLT working with the child, with the idea of practising the activities at home, but the focus was very much on the child and his or her performance. In recognition that speech and language skills develop in a social context through dialogue between the child and surrounding adults, the emphasis and approach has shifted over the years
to focus on the adults’ interactions with the child and on the environment, opportunities and resources
available to the child.26In most cases, these adults are the child’s parents but it may also be staff who spend time with the child in childcare and nursery settings. The assumption behind this approach is that the child has failed to acquire speech and language in the standard/typical environment and thus needs an environment that is highly adapted and more finely tuned to his or her learning needs. Despite this, the
approach, which focuses on the adults’ interactions with the child, does sometimes leave parents with the
impression that their interactions with their child are faulty. This increases the adults’ feelings of guilt
about the origins of their child’s speech and language impairments.27This paradigm shift from the focus
on the child to a focus on the environment is widespread throughout services; however, there is still wide
variation in how services are delivered and in how interventions are described and configured.28
What do we know about these interventions/services?
Although speech and language therapy has been found to be effective for some children, a number of systematic and service reviews have identified some limitations of SLT-led interventions for children with PSLI.
For example, Law et al.29reviewed interventions for children of all ages with PSLI and concluded that the
research to date provided evidence of the effectiveness of interventions that target expressive phonology and expressive vocabulary; interventions that target expressive sentence structure may also be effective as long as there is no accompanying receptive language impairment. The evidence to support interventions targeting receptive language impairment was limited both in terms of the volume of research and the synthesised effect sizes for the existing studies. In terms of how interventions could be delivered, no differences were found between interventions delivered in a group and those delivered in one-to-one contexts or between those delivered by therapists and those delivered by parents who had been trained to deliver an intervention.
Evidence regarding the ideal frequency and amount of intervention (or‘dosage’) has also been inconclusive
so far.30The systematic reviews have identified evidence for the effectiveness of interventions in the short term, that is, for the period of intervention specified in the studies. Although evidence supports early
intervention for children who are growing up in socially deprived conditions,31–34the evidence does not yet
extend to long-term follow-up of preschool children with PSLI; thus, the power of interventions to prevent negative sequelae of a speech and language impairment is not known.
A common finding of those attempting to review and synthesise evidence about the effectiveness of any interventions in speech and language therapy services is that the interventions themselves are poorly
described. For example, Zeng et al.30found that‘teaching sessions’ that were part of an intervention
were rarely described and characteristics of the dosage were not always transparent. Pickstone et al.35
commented on the variety of terminology and the lack of descriptive detail used to describe interventions.
Furthermore, Pickstone et al.35concluded that interventions can have differential effects on subgroups
of children and/or families and also that the effects of any particular component of an intervention are rarely tested and the effects of individual components are difficult to extract from research using complex
interventions. The study by Landry et al.36was a noted exception to this. They found a differential effect of
child’s language. This suggests that a targeted responsiveness rather than merely seeking to increase
a mother’s general responsiveness to her child might be needed for particular changes to occur in a
child’s language.
In 2008 an independent review of services for children and young people with speech, language and
communication needs (SLCN) was commissioned by the UK government.28The review found that speech and
language therapy services in particular were characterised by their variation and were described frequently by
families as a‘postcode lottery’.28The Bercow report recommended a programme of research to enhance the
evidence base to underpin the design of services.28The ensuing research programme, known as the Better
Communication Research Programme (BCRP), surveyed practitioners to identify the interventions in common use by SLTs working with children of all ages and with all types of SLCN. It then reviewed the evidence underpinning these interventions and found that, of the 57 interventions that were either in current use or published in the literature, 3% had strong evidence, 56% had moderate evidence and 39% had only indicative evidence. Interestingly, the intervention most commonly cited by practitioners had only indicative
evidence, that is, good face validity, and lacked any independent external research evidence.37
Relationship between the Better Communication Research Programme and Child Talk
The research of the current programme builds, in a number of ways, on the research carried out by the BCRP team described in the previous section. The principal investigator (PI) for this programme was a member of the core team of researchers for the BCRP. The BCRP was a wide-ranging programme covering all ages of children and young people and the full range of SLCN. The current research programme examines a more focused profile of interventions with a particular age group (preschool) and a particular diagnostic category (PSLI). This enables a closer and more detailed examination of both the interventions appropriate to the group and the evidence. The focus on preschool children was important for two main reasons: the difficulties of providing effective and targeted support (as set out earlier) and the policy imperative, which is driving early identification and intervention for children with PSLI.
Policy imperative promoting early identification
The need for early identification and intervention for children with PSLI continues to be a policy priority
because of the link between children’s early speech and language skills, their broader well-being and
outcomes in later life.10–13,15,16,38–40It is argued that poor communication skills in children are a risk factor for their maltreatment and, later, involvement in the criminal justice system.41,42To date, there is no proven causative association between PSLI in preschool children and either of these outcomes in childhood and later years, or indeed an indication that SLT-led interventions in early childhood would prevent such outcomes. Nonetheless, UK government policy and initiatives have continued to stress the critical role that speech,
language and communication play in a child’s life, health and well-being and to recommend early
identification and intervention.43–45Before the commencement of the Child Talk research programme, the
Better Communication Action Plan46and Healthy Lives Brighter Futures47talked about the government’s
commitment to a range of improvements. These included early identification and intervention; better
information for parents; a reduction in the variability and inequality of services; and increased individualisation of services for children with disabilities, particularly those with SLCN. Over the last 3 years of this research there has been an ongoing emphasis within government and other reports stressing the importance of the
link between children’s language and their life chances, alongside a focus on children’s language in relation
to the education curricula and training of the workforce.44,48,49
In summary, PSLI is a high-prevalence condition with the potential to have a negative impact, which has resulted in calls for and expectations of early identification and intervention so that children can benefit from social and educational experiences and to mitigate negative sequelae. The evidence base for
early intervention is growing but is underdeveloped, particularly in terms of informing the individualisation of interventions for what is a heterogeneous condition. The social context in which language is acquired adds to the heterogeneity. It is vital to understand how best to shape interventions to best suit the particular needs of each child and his or her family.
Assumptions underpinning an evidence-based framework
The purpose of this research was to investigate whether or not it is possible to develop an evidence-based framework that can support the decision-making of SLTs as they attempt to design and plan interventions that are appropriate to the needs of individual children and their families. Most people are now familiar
with the notion of evidence-based practice (EBP) and the seminal definition of Sackett et al.,50which
suggests that EBP occurs when external research evidence is applied with expertise and in the light of
patient preferences; others have also emphasised the role of context in framing EBP.51Various barriers to
the implementation of EBP have been identified including the time needed to search out research and, in particular, research that is relevant and appropriate to the particular context of an individual patient.52 There is also a lack of research that attempts to advance our understanding of the process of integration of the three elements.
The emphasis to date, from both research and practice, has been on the systematic research element of EBP rather than on clinical expertise or patient preferences. For example, practitioners are taught how to search out and appraise research and are given advice on how to address the barriers to EBP that have
been identified.53Despite this emphasis, there has been a number of discussions that have challenged the
use of‘evidence’ to mean only research evidence,54arguing, for example, that many different kinds of
‘evidence’ are used in clinical decision-making. However, this confuses the idea of systematic research evidence and knowledge. Practitioners draw on various types of knowledge to make their clinical
decisions.55However, it is suggested that these other types of knowledge are more usefully considered as
part of clinical expertise.56In this research programme the‘evidence’ component of EBP is taken to refer
only to evidence gained from external, published, systematic research.
Research regarding the nature of clinical expertise and the process of clinical decision-making has rarely
been the focus of research or discussion within speech and language therapy. Roulstone56describes clinical
expertise as‘the skilful and appropriate application of knowledge to the practice situation’ (p. 45). Given
the heterogeneous PSLI population, the current dearth of systematic research evidence regarding the individualisation of interventions and the lack of prominence of any particular approach to intervention, the expert practitioner applies and adapts knowledge from a variety of sources (including whatever there is from systematic research). Experts organise their knowledge to be optimally useful to the clinical context
in order to retrieve it efficiently when needed.57Experts develop‘theories of practice’ that guide their
everyday decisions.58Therefore, in developing an evidence-based framework, it is necessary to investigate
and understand how everyday practice is framed by practitioners and how the research evidence relates to that practice.
In 1991, The Patient’s Charter stated that patients have the right to a clear explanation about proposed
treatments.59In the context of EBP, therefore, there is a need to provide patients with information about
the evidence so that their choices and preferences can take account of the evidence base. Patients’
preferences exert an important influence on the success of interventions.56At the extreme, if patients do
not believe in, or understand, an intervention they may not attend appointments or follow through on interventions. Therefore, to develop an evidence-based framework, some conceptualisation is needed of patient views both of the nature of a disorder and of the possible interventions.
In conclusion, an evidence-based framework of speech and language therapy for children with PSLI will take account of clinical expertise and the perspectives of service users so that these can be integrated with evidence from external research.