Minimal Clinically Important Difference on Cognitive Measures for Huntington's Disease Using Function as an Anchor

Area of Science:

• Neuroscience
• Clinical Research
• Biostatistics

Background:

• Cognitive decline is a key feature of Huntington's disease (HD), impacting daily function.
• Interpreting the clinical significance of cognitive changes in HD trials is challenging.
• Functional capacity measures can serve as anchors to define minimally clinically important differences (MCID) in cognition.

Purpose of the Study:

• To estimate MCID for common cognitive measures in HD using functional capacity anchors.
• To compare MCID estimates derived from functional capacity versus health impairment (SF-12).

Main Methods:

• Analysis of Enroll-HD study data from participants with Stage 2 and 3 HD.
• Utilized linear mixed-effects regression to estimate MCID at 12, 24, and 36 months.
• Employed the smallest measurable change in functional capacity as anchors.

Main Results:

• Cognitive changes associated with functional decline were more pronounced with disease progression and longer timeframes (p < 0.05).
• MCID estimates using functional capacity anchors were comparable to those using health impairment.
• Health impairment anchors yielded larger MCID estimates at 36 months (p < 0.05).

Conclusions:

• MCID estimates for cognitive measures in HD are dependent on disease stage and observation period.
• Anchoring MCID on everyday functional measures enhances the interpretation of cognitive changes in HD.
• This approach aids in understanding the real-world impact of cognitive alterations in Huntington's disease.