Small N designs for rehabilitation research.

Area of Science:

• Rehabilitation research
• Clinical trial design
• Evidence-based practice

Background:

• Rehabilitation research is plagued by statistical challenges, including sample size requirements conflicting with recruitment goals.
• Underpowered studies and recruitment issues are common in rehabilitation research.
• Randomized clinical trials (RCTs) often lack generalizability, are costly, and may not suit all research areas like assistive technologies.

Purpose of the Study:

• To discuss the challenges in rehabilitation research design and analysis.
• To present single-case designs as a suitable alternative for specific research contexts.
• To provide recommendations for conducting effective single-case studies.

Main Methods:

• Review of statistical and design challenges in rehabilitation research.
• Comparison of randomized clinical trials (RCTs) and single-case designs.
• Discussion of theoretical, methodological, and clinical considerations for single-case designs.

Main Results:

• RCTs have limitations in generalizability, cost, and applicability to certain rehabilitation interventions.
• Single-case designs are well-suited for studies focusing on behavior change and functional status with small sample sizes (typically <30).
• Experimental and quasi-experimental single-case designs can contribute valuable evidence.

Conclusions:

• Single-case designs offer a practical and effective approach for specific rehabilitation research questions.
• Careful design and execution of single-case studies are crucial for building a robust evidence base.
• Researchers should consider single-case designs when RCTs are not feasible or appropriate.