RESUMEN
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 [d(w) ]) was compared across training types. RESULTS: The overall effect size across all intervention studies was d(w) =0.56. A comparison between classes of intervention showed strong effects for task-oriented intervention (d(w) =0.89) and physical and occupational therapies (d(w) =0.83), whereas that for process-oriented intervention was weak (d(w) =0.12). Of the chemical supplements, treatment with methylphenidate was researched in three studies (d(w) =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.