SLTAs can act as effective surrogates for SLTs in the delivery of services within primary schools to children with primary language impairment who do not to require the specialist skills of an SLT. Generalising the central estimates of the relative cost of different therapy modes to other educational/health systems is possible, but the precise differences reported in resource use need to be qualified by the level of programme intensity and other characteristic features of education and therapy services that may differ from those observed in this trial. Further research is needed into effective interventions for receptive language problems and also investigations of the efficacy of the relationship between dose and treatment effect in both expressive and receptive language. Research is also needed into models of integrative service delivery, cluster models of delivery via integrated community schools, and the involvement of class teachers, classroom assistants and parents/carers. There is also a need for studies to identify the characteristics of children who are most likely to succeed with indirect intervention approaches, and also to evaluate alternative methods of working with those who may benefit from different modes. Finally, research to refine the therapy manual would also be helpful.

Seventy-seven children between the ages of 6 and 10 years, with severe mixed receptive-expressive specific language impairment (SLI), participated in a randomized controlled trial (RCT) of Fast ForWord (FFW; Scientific Learning Corporation, 1997, 2001). FFW is a computer-based intervention for treating SLI using acoustically enhanced speech stimuli. These stimuli are modified to exaggerate their time and intensity properties as part of an adaptive training process. All children who participated in the RCT maintained their regular speech and language therapy and school regime throughout the trial. Standardized measures of receptive and expressive language were used to assess performance at baseline and to measure outcome from treatment at 9 weeks and 6 months. Children were allocated to 1 of 3 groups. Group A (n = 23) received the FFW intervention as a home-based therapy for 6 weeks. Group B (n = 27) received commercially available computer-based activities designed to promote language as a control for computer games exposure. Group C (n = 27) received no additional study intervention. Each group made significant gains in language scores, but there was no additional effect for either computer intervention. Thus, the findings from this RCT do not support the efficacy of FFW as an intervention for children with severe mixed receptive-expressive SLI.

SLTs have a contribution to make at all tiers, but where prioritization for clinical services is a necessity, we need to establish the relative benefits and cost-effectiveness at each tier. Good evidence exists for SLTs delivering direct individualized intervention and we should ensure that this is available to children with pervasive and/or complex language disorders. In cases where service models are being provided which lack evidence, we strongly recommend that SLTs investigate the effectiveness of their approaches.

Intervention in this age group can be effective for expressive language and can be delivered equally effectively though speech and language therapy assistants and to children in groups.

Background: Many school-age children with language impairments are enrolled in mainstream schools and receive indirect language therapy, but there have been, to the authors' knowledge, no previous controlled studies comparing the outcomes and costs of direct and indirect intervention delivered by qualified therapists and therapy assistants, and each delivery mode offered to children individually or in groups. Aims: To investigate the relative effectiveness of indirect and direct intervention therapy modes delivered individually or in groups for children with primary language impairment. Methods & Procedures: A multi-centre randomized controlled trial investigated 161 children with primary language impairment aged 6-11 years randomized to a usual-therapy control group or to direct individual, indirect individual, direct group or indirect group therapy modes. Intervention was delivered three times a week for 30-40-min sessions in mainstream schools over 15 weeks. Language performance was assessed at baseline, post-therapy and at 12 months. Cost analysis was based on salary and travel costs for intervention modes and usual therapy.

At present, the more efficacious therapy is that delivered by speech and language therapists or speech and language therapy assistants to children individually or in groups. This may be related to more faithful adherence to the interventions schedule, and to a probably greater amount of language-learning activity undertaken. Intervention delivered via school-based 'consultancy' approaches in schools will require to be carefully monitored by schools and SLT services.

15Background: Lack of agreement about criteria and terminology for children's language 16 problems affects access to services as well as hindering research and practice. We report the 17 second phase of a study using an online Delphi method to address these issues.

RCT Randomized controlled trial RELI Receptive-expressive language impairment SES Standardized effect size SLI Specific language impairment SLT Speech and language therapist Studies indicate that language impairment that cannot be accounted for by factors such as belowaverage non-verbal ability, hearing impairment, behaviour or emotional problems, or neurological impairments affects some 6% of school-age children. Language impairment with a receptive language component is more resistant to intervention than specific expressive or phonological delays, and carries a greater risk of comorbid behavioural difficulties as well as adverse outcomes for language development and academic progress. This paper considers underlying explanations that may account for receptive-expressive language impairment. It also reviews evidence for the effectiveness of intervention from theory and recent systematic reviews, trials, and speech and language therapy practice.Children with receptive-expressive language impairment (RELI), also referred to as 'receptive language disorder' 1 or 'mixed receptive-expressive disorder', 2 form a subset of those with speech, language, and communication needs who commonly have problems understanding both spoken and written language. They have particular difficulties in comprehending vocabulary and grammar and inferring meaning and will also have problems with expressive language. Some may have difficulties in pragmatics, i.e. the use of language in social contexts. 3 Population studies indicate that some 6% of 5-year-old children have significant difficulties in language functioning. 4,5 However, variability is observed across studies in the stringency of criteria and the nature of the measures used to define language impairment. 6,7 For example, composite scores are often used which do not distinguish between the child's language production (expressive language skills) and understanding of language (receptive language skills). However, studies that do make this distinction indicate that 2 to 4% of 5-year-olds have RELI. 5,8 A detailed study of referral rates in one primary care trust in the UK (providing local community health services based on 1100 referrals to speech and language therapists [SLTs] over a 15-month period 9 ) would suggest a UK prevalence of 4.5%, which is at the higher end of these estimates. Caution is required, however, as local factors such as staffing and resources for intervention would have influenced referral patterns.RELI is likely to have a marked long-term impact on the outcomes for language development, 10-12 literacy, 10,12,13 behaviour, and social development. 12,14,15 There are links also to mental health problems. 16,17 Studies consistently reveal that RELI is a higher risk factor for adverse long-term outcomes than specific expressive language impairment (ELI), which highlights the importance of effective early intervention.Intervention for RELI may be informed by an understanding of levels of explanation based upon relevant theory and probable underlying mechanis...