Single-subject research designs in pediatric rehabilitation: a valuable step towards knowledge translation

Knowledge translation may be particularly challenging in pediatric rehabilitation, where study findings are often ambiguous owing to low statistical power or inconsistent responses to intervention. Disconnection between research protocols and clinical practicality, as well as variability of responsiveness in heterogeneous pediatric populations, may further impede integration of research findings into everyday practice. Use of single-subject research designs (SSRDs) may bridge the gap between research and practice, with robust design options that better identify and preserve patterns of responsiveness to specific interventions and offer protocols that are more readily implemented in practice settings than can be done in traditional randomized controlled trials. This review defines SSRD, provides examples of research questions that can be answered using SSRD, details the experimental designs that can be used and the level of evidence of each design, and describes statistical analysis approaches and clinical application. This analysis will aid researchers, reviewers, clinicians, and others in better understanding SSRD methodology and its application in everyday practice.