Use of single-subject research designs in seating and wheeled mobility research: a scoping review

Background: Evidence-based practice (EBP) in seating and wheeled mobility practice is often hindered by a dearth of published research. Purpose: The purpose of this review was to explore and critically appraise the use of single-subject research designs (SSRDs) in seating and wheeled mobility studies published between January 1995 and May 2018. Study Selection: Primary source, peer-reviewed SSRDs focused on exploring the impact of a seating and wheeled mobility intervention were included in the review. Data Extraction: Relevant data extraction, determination of level of evidence, evaluation of methodological rigor, and assessment of the risk of bias were each independently performed. Data Synthesis: The review yielded 19 studies (2 Level III, 15 Level IV, and 2 Level V). A majority of these studies incorporated a withdrawal-type of SSRD and involved subjects representing patient populations with seating and wheeled mobility needs. Methodological rigor/quality features most commonly absent in the included studies included: blinding/masking, inter-rater or intra-rater reliability, >5 data points in each phase, planned replication (>= 3 subjects), procedural fidelity methods, randomization, stability of the data during baseline, statistical analyses and use of subject selection criteria. The limited number of published SSRDs, combined with the lower levels of evidence (Levels III-V) provided by these studies, indicates that the use of SSRDs in seating and wheeled mobility research is in the early stages of development. Conclusions: Increasing the methodological quality and rigor as well as reporting methods in future SSRDs involving seating and wheeled mobility interventions may help to support EBP in this area. IMPLICATIONS FOR REHABILITATION Single-subject research designs (SSRDs) offer both researchers and clinicians the opportunity to contribute to the existing knowledge base in ways that reflect actual clinical practice. SSRDs provide flexibility in adapting and modifying seating and wheeled mobility-related assistive technology devices to meet the individual needs of specific subjects. SSRDs preserve individual responses to seating and wheeled mobility-related assistive technology devices. SSRDs may help to enhance evidence-based practice (EBP) in seating and wheeled mobility practice by spanning the divide between research and practice. Increasing the methodological quality and rigor as well as reporting methods in future SSRDs may help to support EBP in seating and wheeled mobility practice.