Abstract Details

Title Integrated Alzheimer’s Disease Rating Scale (iADRS): Clinically Meaningful Change Estimates

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) P6 - Poster Session 6 (5:30 PM-6:30 PM)

Poster/Presentation
Number 3-004

Background Clinical trials for new therapies of Alzheimer’s disease (AD) are enrolling patients earlier on disease continuum with objectives of lengthening the duration of higher cognitive function before decline and intervening before pathological changes are severe. While it is well accepted that changes in cognition underlie changes in function, oftentimes separate scales are used to assess these two highly related outcomes. The integrated Alzheimer’s Disease Rating Scale (iADRS), a composite of two widely accepted measures, the Alzheimer’s Disease Assessment Scale – Cognitive Subscale 13-item version (ADAS-Cog₁₃) and the Alzheimer’s Disease Cooperative Study – instrumental activities of daily living scale (ADCS-iADL), was developed. The iADRS has been validated, its statistical properties have been described, and the scale has been used as a clinical outcome measure in previous phase 2 and 3 clinical trials in AD. The iADRS was effective in capturing disease progression from MCI throughout moderate AD, as well as treatment effects across early disease spectrum.However, questions remain, including what magnitude of change on the iADRS represents meaningful change for patients with AD.

Objective To establish a minimal clinically important difference (MCID) on the iADRS and enhance understanding of iADRS point changes in clinical trials.

Design/Methods Using data from phase 3 EXPEDITION3 and AMARANTH, and phase 2 TRAILBLAZER-ALZ clinical trials, MCID will be defined using combination of anchor-based and distribution-based methods. The anchor-based approach will identify participants experiencing meaningful change using established clinically relevant scales. Distribution-based estimates will be derived by identifying a threshold of score changes below which the “change” most likely reflects measurement error, considering variability of scores and reliability of the measure.

Results Anchor-based and distribution-based estimates for MCID for iADRS are not yet available for the abstract but will be presented during the meeting.

Conclusions Conclusion will be provided during the meeting, after data are available.

Authors/Disclosures
Ellen Dennehy (Eli Lilly) PRESENTER	Ellen Dennehy has received personal compensation for serving as an employee of Eli Lilly. Ellen Dennehy has stock in Eli Lilly.
Dorene M. Rentz, PsyD (Brigham and Women's Hospital)	Dr. Rentz has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Digital Cognition Technologies. Dr. Rentz has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Neurotrack.
Alette Wessels	No disclosure on file
Michael G. Case, MS (Eli Lilly and Company)	Mr. Case has received personal compensation for serving as an employee of Eli Lilly and Company. Mr. Case has received stock or an ownership interest from Eli Lilly and Company.
John R. Sims, MD (Eli Lilly)	Dr. Sims has received personal compensation for serving as an employee of Eli Lilly and Company. Dr. Sims has stock in Eli Lilly and Company.