Is the difference real, is the difference relevant: the minimal detectable and clinically important changes in the...

Area of Science:

• Neuroscience
• Clinical Neurology
• Rehabilitation Medicine

Background:

• The Montreal Cognitive Assessment (MoCA) is essential for evaluating cognitive function in stroke survivors.
• Accurate interpretation of MoCA score changes requires understanding the minimal detectable change (MDC) and minimal clinically important difference (MCID).

Purpose of the Study:

• To determine the MDC and MCID of the MoCA within six months post-stroke.

Main Methods:

• A cohort study analyzed data from the EFFECTS trial, administering the MoCA at baseline and 6-month follow-up.
• MDC was calculated using the standard error of the MoCA mean.
• MCID was established using anchor-based methods (Stroke Impact Scale, Euro Quality of Life-5 Dimensions) and a distribution-based method (Cohen's benchmark effect size).

Main Results:

• The study included 1131 stroke survivors (mean age 71 years).
• Mean MoCA scores improved from 22 (SD 5.2) at baseline to 25 (SD 4.2) at 6 months.
• The MDC for MoCA was 5.1 points. Anchor-based MCIDs were 2 points (SIS) and 1.6 points (EQ-5D). The distribution-based MCID was 1 point.

Conclusions:

• Even minor MoCA score changes can be significant for stroke survivors.
• Larger differences are needed to confirm true changes beyond inherent test variability.
• Anchor analysis results should be interpreted cautiously due to small sample sizes.