Which treatment is better? Ascertaining patient preferences with crossover randomized controlled trials

Area of Science:

• Clinical Trial Design
• Palliative Care Research
• Patient-Reported Outcomes

Background:

• Parallel randomized controlled trials (RCTs) face challenges in determining patient-reported outcomes due to interindividual variability and subjective interpretation.
• Minimal clinically significant differences are often unavailable or not individualized, complicating outcome assessment in parallel RCTs.
• Crossover RCTs enable intraindividual comparisons, directly addressing patient perspectives on effectiveness, adverse effects, and usability.

Purpose of the Study:

• To review key design elements of crossover trials.
• To compare the advantages and disadvantages of crossover versus parallel designs.
• To explore the utility of crossover trials in palliative care research with case examples.

Main Methods:

• This study employed a narrative review methodology.
• The review synthesized information on crossover trial design and application.

Main Results:

• Crossover studies randomize patients to a sequence of treatments, facilitating intraindividual comparisons.
• These trials typically require smaller sample sizes than parallel designs, leading to reduced costs.
• Feasibility requires stable conditions and short-term intervention effects; inadequate washout periods or prolonged duration can pose interpretation challenges and increase attrition risk.

Conclusions:

• Crossover studies provide unique data on superior interventions by enabling intraindividual comparisons and capturing patient preferences.
• The design is particularly suited for specific palliative care research applications.
• Consideration of crossover designs is recommended for selected palliative care studies.