Does More Speech Therapy Lead to Better Results in Childhood Apraxia of Speech? A Systematic Review and Meta‐Analysis of the Available Evidence
Patricia McCabe, Donna C. Thomas, Jessica Xue Ming Choo, Rob Heard, Denise NgABSTRACT
Background
In recent years there has been a significant increase in the number and quality of childhood apraxia of speech (CAS) treatment research published. Much of this research has focussed on establishing treatment efficacy and identifying treatment components. A smaller subset of the literature has looked at treatment intensity, such as comparing therapy delivered twice per week with four times per week, however this literature has not been compared across interventions.
Aims
This systematic review and meta‐analysis examines cumulative intervention intensity and its components (dose per session, dose frequency, intervention duration—number of weeks) and reported treatment effects to understand whether there is a relationship between dose and effect in specific treatments or overall.
Methods
A systematic search and review was registered with Prospero (CRD420251107259). Twelve electronic databases were searched supplemented by handsearching references lists. Included studies were coded for CAS diagnosis confidence, methodological quality, dose characteristics, and treatment outcomes. Standard mean difference (SMD), an effect size metric equivalent to Cohen's d , was calculated for 25 included papers and weighted Pearson's correlations performed to identify relationships between dose characteristics and treatment outcomes.
Main Contribution
This paper is the first to (1) create omnibus standard effect sizes across diverse interventions and (2) show the relationship between intensity and treatment outcome in children with CAS. The omnibus SMD across studies with three or more participants for treated items was 1.22 (confidence interval 0.76–1.67), a large effect, and for generalisation items was 0.66 (confidence interval 0.46–0.85) which is a moderate effect. These results show that CAS treatment works in well‐controlled studies when delivered at least twice per week for at least 45 min per session.
The relationship between intensity variables and generalisation SMD was less clear with weeks of therapy being moderately correlated ( r = 0.39) and none of the other variables showing any relationship with study SMD. These results should be interpreted carefully as there was significant missing data and limited range in some variables. Researchers need to include more standard intensity information in reporting their results.
Conclusions
Treatment for CAS is effective and leads to moderate generalisation; more weeks of therapy leads to stronger gains than fewer weeks of therapy.
WHAT THIS PAPER ADDS
What is already known on this subject
CAS is a neurological‐based motor speech disorder that originates in childhood for which there are a number of effective treatments. For this population, high intensity treatment is recommended—over 100 production trials per session, 2–5 sessions per week, across an extended period. In studies which directly compare intensity of variables, more therapy (e.g. 20 sessions) results in greater improvement than less therapy (e.g. 10 sessions). There are no previous meta‐analyses of intensity variables—dose, dose frequency, treatment duration, or cumulative intervention intensity in CAS
This study compiles data from 25 studies with a low risk of bias and high CAS diagnostic confidence in a meta‐analysis of the dose effects of CAS treatment. The meta‐analysis shows that CAS treatment in general works. Most studies had 2–4 sessions per week across 3–12 weeks. Within this narrow band of intensity, a significant correlation was shown between the number of weeks of therapy and outcome. There is no significant evidence for CAS therapy less frequently than twice per week at this time. Eight different treatments demonstrated efficacy for improving speech outcomes in children with CAS.