Abstract Details

Title Incorporating Patient Perspectives into a Composite Score for Measuring Disease Progression in Spinocerebellar Ataxia (SCA)

Topic Movement Disorders

Presentation(s) P12 - Poster Session 12 (11:45 AM-12:00 PM)

Poster/Presentation
Number 5-028

Objective To incorporate patients’ perspectives into the statistically-derived spinocerebellar ataxia composite score (SCACOMS).

Background SCACOMS was derived using partial least squares (PLS) regression to objectively determine item weights for the candidate 5 items (4 items from the f-SARA and clinicians global impression of change [CGI-C]). This scale was optimized to detect disease progression in patients with SCA, with more progressive items given higher weights.

Design/Methods Item weights derived statistically were compared to relative importance assigned to the items by N=24 patients with SCA who participated in semi-structured interviews. SCACOMS item weights were adjusted by 1) 50/50 combination of statistically-derived and patient-stated weights and 2) reducing maximum weight of CGI-C to 20% before averaging the remaining item weights. The 1-year mean to standard deviation ratios (MSDRs) were compared for these approaches; larger MSDRs indicated greater sensitivity to measure progression.

Results SCACOMS items’ PLS regression weights and patient assigned median weights, respectively, are: gait (12% vs 30%), stance (17% vs 17%), sitting (8% vs 10%), speech (10% vs 25%), and CGI-C (53% vs 13%). The MSDR for the PLS-derived SCACOMS is 0.99. The MSDR obtained incorporating patient weights is 0.70. When the weights are averaged across the 2 sources, the resulting MSDR is 0.91. When CGI-C is set to a maximum of 20% of the total composite and the remaining f-SARA item weights averaged, the MSDR is 0.79, indicating that the CGI-C item is a driver of scale responsiveness.

Conclusions This study took a novel approach to enhance the validity of a composite measure SCACOMS. The resulting scale, with an updated set of SCACOMS item weights, effectively balances scale responsiveness with patient-relevance. Incorporating results of qualitative patient validation weighting with the PLS-derived weighting may increase acceptance and adoption of composite measures, which are more likely to accurately track disease progression and identify effective treatments.

Authors/Disclosures
Michele Potashman, PhD (Biohaven) PRESENTER	Dr. Potashman has received personal compensation for serving as an employee of Biohaven Pharmaceuticals.
Basia Rogula	Basia Rogula has received personal compensation for serving as an employee of Broadstreet HEOR.
Lauren Powell (Broadstreet HEOR)	Lauren Powell has nothing to disclose.
Ellen Korol (Broadstreet HEOR)	Ellen Korol has received personal compensation for serving as an employee of Broadstreet HEOR.
Samuel Dickson (Pentara Corporation)	Mr. Dickson has nothing to disclose.
Suzanne Hendrix, PhD (Pentara)	Dr. Hendrix has received personal compensation for serving as an employee of Pentara Corporation. Dr. Hendrix has received personal compensation in the range of $50,000-$99,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Pentara Corporation. Dr. Hendrix has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Pentara Corporation. The institution of Dr. Hendrix has received personal compensation in the range of $0-$499 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Pentara Corporation. Dr. Hendrix has or had stock in Pentara.
Maggie Heinrich (Parexel)	Maggie Heinrich has received personal compensation for serving as an employee of Parexel.
Katja Rudell (Parexel)	No disclosure on file
Linda Abetz Webb	The institution of Linda Abetz Webb has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Parexel.
Melissa Beiner	Melissa Beiner has received personal compensation for serving as an employee of Biohaven Pharmaceuticals. Melissa Beiner has stock in Biohaven Pharmaceuticals.
Vlad Coric	No disclosure on file
Liana Rosenthal, MD (Johns Hopkins School of Medicine)	Dr. Rosenthal has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biohaven Pharmaceuticals. Dr. Rosenthal has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Reata Pharmaceuticals. Dr. Rosenthal has received research support from NIH. Dr. Rosenthal has received research support from Gordon and Marilyn Macklin Foundation. Dr. Rosenthal has received research support from The Daniel B. and Florence E. Green Foundation. Dr. Rosenthal has received research support from National Ataxia Foundation. Dr. Rosenthal has received research support from Michael J. Fox Foundation. Dr. Rosenthal has received research support from Pfizer. Dr. Rosenthal has received research support from Biohaven Pharmaceuticals. Dr. Rosenthal has a non-compensated relationship as a Medical Director, ex-officio Member of the Board with National Ataxia Foundation that is relevant to AAN interests or activities.
Susan L. Perlman, MD (UCLA)	Dr. Perlman has nothing to disclose.
Jeremy D. Schmahmann, MD, FAAN (Massachusettes General Hospital)	Dr. Schmahmann has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Biohaven. The institution of Dr. Schmahmann has received research support from National Ataxia Foundation. The institution of Dr. Schmahmann has received research support from Biohaven. Dr. Schmahmann has received intellectual property interests from a discovery or technology relating to health care. Dr. Schmahmann has received publishing royalties from a publication relating to health care. Dr. Schmahmann has received publishing royalties from a publication relating to health care. Dr. Schmahmann has received publishing royalties from a publication relating to health care.
Gilbert J. L'Italien	Gilbert J. L'Italien has received personal compensation for serving as an employee of Biohaven Pharmaceuticals. Gilbert J. L'Italien has stock in biohaven pharmaceuticals.

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