N-of-1 Trials in Neurology: A Systematic Review

Area of Science:

• Neurology
• Clinical Trials
• Evidence-Based Medicine

Background:

• N-of-1 trials, or single-patient crossover trials, are increasingly used in neurologic disorders.
• These trials provide personalized evidence for treatment efficacy.
• A systematic review was conducted to assess their quality and reporting.

Purpose of the Study:

• To systematically review published N-of-1 trials in neurologic disorders.
• To assess the methodologic quality and reporting standards of these trials.
• To identify areas for improvement in future N-of-1 trial design and reporting.

Main Methods:

• A comprehensive search of PubMed, MEDLINE, and Embase databases was performed up to December 1, 2019.
• Data extracted included trial design, disease, intervention, analysis, and treatment success.
• Methodologic quality and reporting were assessed using the Consolidated Standards of Reporting Trials extension for N-of-1 trials (CENT) 2015 criteria and the Jadad score.

Main Results:

• Forty N-of-1 trial reports were identified, primarily in neuromuscular and neurodegenerative/movement disorders.
• Interventions included pharmacologic agents, electric stimulation, and nutritional products.
• Mean CENT and Jadad scores indicated suboptimal methodologic quality and reporting.

Conclusions:

• N-of-1 trials are a valuable, emerging tool in neurology, applicable to both stable and progressive disorders.
• Improving methodologic quality and reporting by following CENT guidelines is crucial for future trials.
• These trials can bridge the gap between research and clinical care by providing personalized Level 1 evidence.