Abstract
To examine the equivalency of ECAS versions A, B, and C in an Irish cohort, and to examine potential practice effects, 236 healthy controls were recruited through the Irish ALS control database. One hundred and seventy-six (176) controls completed ECAS version A, B, or C. Separately, 60 controls completed all three versions (A–B–C), consecutively, four months apart. TOST analysis found that ECAS A was equivalent to ECAS B and C. ECAS B and C were not statistically equivalent, however the difference between them was minimal. Participants showed improvement in ECAS performance over time, indicative of practice effects. Significant improvement was observed from time 1 to 2, but not from time 2 to 3. We propose Irish specific reliable change index (RCI) scores that take into consideration practice effects and measurement error. These thresholds will help quantify clinically meaningful cognitive decline in ALS patients, leading to improved quality of care.
Acknowledgements
The authors thank all those who participated in this research study.
Disclosure statement
No conflict of interest was reported by Emmet Costello, Katie Lonergan, Caoifa Madden, Meadhbh O’Sullivan, Iain Mays, Mark Heverin, Marta Pinto-Grau, and Niall Pender. Orla Hardiman Prof. Orla Hardiman has received speaking honoraria from Janssen Cilag, Biogen Idec, Sanofi Aventis, Novartis and MerckSerono. She has been a member of advisory panels for Biogen Idec, Allergen, Ono Pharmaceuticals, Novartis, Cytokinetics and Sanofi Aventis. She serves as Editor-in-Chief of Amyotrophic Lateral Sclerosis and Frontotemporal Dementia.
Data availability
The dataset analyzed during the current study are available from Mr. Mark Heverin, Research Manager, upon reasonable request.