Efficacy of interventions to improve motor performance in children with developmental coordination disorder: a combined systematic review and meta-analysis.

Aim The aim of this study was to review systematically evidence about the efficacy of motor interventions for children with developmental coordination disorder (DCD), and to quantify treatment effects using meta-analysis. Method Included were all studies published between 1995 and 2011 that described a systematic review, (randomized) clinical trial, or crossover design about the effect of motor intervention in children with DCD. Studies were compared on four components: design, methodological quality, intervention components, and efficacy. Twenty-six studies met the inclusion criteria for the review. Interventions were coded under four types: (1) task-oriented intervention, (2) traditional physical therapy and occupational therapy, (3) process-oriented therapies, and (4) chemical supplements. For the meta-analysis, effect sizes were available for 20 studies and their magnitude (weighted Cohen's d [dw]) was compared across training types. Results The overall effect size across all intervention studies was dw=0.56. A comparison between classes of intervention showed strong effects for task-oriented intervention (dw=0.89) and physical and occupational therapies (dw=0.83), whereas that for process-oriented intervention was weak (dw=0.12). Of the chemical supplements, treatment with methylphenidate was researched in three studies (dw=0.79) and supplementation of fatty acids plus vitamin E in one study (no effect). The post hoc comparison between treatment types showed that the effect size of the task-oriented approach was significantly higher than the process-oriented intervention (p=0.01) and comparison (p=0.006). No significant difference in the magnitude of effect size between traditional physical and occupational therapy approaches and any of the other interventions emerged. Interpretation In general, intervention is shown to produce benefit for the motor performance of children with DCD, over and above no intervention. However, approaches from a task-oriented perspective yield stronger effects. Process-oriented approaches are not recommended for improving motor performance in DCD, whereas the evidence for chemical supplements for children with DCD is currently insufficient for a recommendation.