Evaluating Treatment Efficacy of Two Syntactic Treatment Procedures for Children With Specific Language Impairment (SLI): A Randomized Controlled Trial

Specific-language-impairment (SLI) is defined as a significant disorder in language development, which affects one's daily functioning, but not attributable to sensory, intellectual or neuropsychological deficit. Children with SLI make up one of the largest subgroups of students with special educational needs (SEN) in Hong Kong. Without appropriate intervention, SLI may persist into adolescence and lead to long-term literacy difficulties and social rejection, which were found to be associated with societal problems like unemployment and crime commitment. Among the language domains, syntax/grammar has been viewed as a core deficit in these children. Speech-Language-Pathologists (SLPs) often provide intervention on this aspect for them. However, very few intervention efficacy studies could be identified.

Without pertinent research evidence, clinical-decision-making in treatment approach selection may be dubious. This study aims to evaluate the efficacy of two procedures for syntax intervention, namely the Sentence-Combining (SC) and Narrative-Based (NAR) procedures using a randomized-controlled-trial (RCT) design. These two procedures have been indicated to be effective in previous case reports and expert opinions. By using the rigorous study design of RCT, this study provides stronger evidence to support clinicians in determining the most effective treatment procedure. To achieve sufficient statistical power to detect the treatment difference, 52 children with SLI will be recruited and randomly assigned to one of the treatment groups. The primary outcome will be measured by a standardized language assessment. Intention-to-treat analysis will be employed. Pre- and post-treatment scores on the outcomes will be subject to analyses of covariance with the pre-treatment scores as the covariate.

• Behavioral: Syntax treatment via sentence-combining method

  Sentence combining method is a discrete trial method that teaches children to form complex sentences of a same structure through drilling and modeling.

  Treatments are conduced by school-speech therapist once two weeks for 8 sessions.

• Behavioral: Syntax treatment managed by narrative-based treatment
  Target structures are embedded into narrative stories. Children are exposed to these stories and are scaffolded to form the target sentence structure through answering questions, cloze passage and story retell. Treatment are conduced by school-speech therapist once two weeks for 8 sessions.

• Experimental: Sentence combining
  Intervention: Behavioral: Syntax treatment via sentence-combining method
• Active Comparator: Narrative based method
  Intervention: Behavioral: Syntax treatment managed by narrative-based treatment

Inclusion Criteria:

• children in school years who were diagnosed as language with or with speech impairment by a qualified speech therapist; and
• children failed in a standardized language assessment

Exclusion Criteria:

• children with sensory impairment and other diagnosed developmental disorders such as autism.