Composite endpoints, including patient reported outcomes, in rare diseases

Area of Science:

• Clinical Trials Methodology
• Biostatistics
• Rare Diseases Research

Background:

• Single endpoints are insufficient for complex rare diseases.
• Existing composite endpoint methods have limitations in outcome types and sample size.
• Patient-reported outcomes are often excluded from composite analyses.

Purpose of the Study:

• Introduce generalized pairwise comparisons for rare disease trials.
• Demonstrate the utility of these methods in analyzing composite endpoints.
• Incorporate patient-reported outcomes into efficacy assessments.

Main Methods:

• Utilized non-parametric generalized pairwise comparisons.
• Applied methods to a post-hoc analysis of a small-sample epidermolysis bullosa trial.
• Included quality of life as a patient-relevant outcome in a composite endpoint.

Main Results:

• Generalized pairwise comparisons accommodate any number and type of outcomes.
• The methodology shows good small-sample properties.
• Enabled prioritization of outcomes by clinical severity and inclusion of a clinical relevance threshold.

Conclusions:

• Generalized pairwise comparisons are a promising statistical methodology for rare disease trials.
• This approach allows for better evaluation of therapy efficacy.
• Facilitates the inclusion of patient-reported outcomes alongside disease-specific measures.