Clinical Supplies
The evolution of cognitive assessment technology demands a delicate balance. When moving from established desktop systems to flexible web-based platforms, the question isn't just whether it works—it's whether precision survives the transition.
At the 2023 ISCTM Scientific Meeting, Signant Health presented validation data that answers this question definitively for the CDR System™, one of the most widely used computerized cognitive assessment systems in clinical research over the past 40 years.
Why this validation matters
Cognitive assessments measure reaction times in milliseconds. This precision forms the foundation for detecting subtle changes in cognition that can signal treatment efficacy in Alzheimer's disease, depression, ADHD, and other CNS conditions. Even small variations in measurement accuracy can mask real treatment effects or create false signals.
The challenge: traditional cognitive testing relied on dedicated hardware laptops with specialized button boxes that ensured consistent, precise reaction time capture. The opportunity: web-based systems enable decentralized trials, home-based testing, and broader patient access. The risk: compromising the measurement precision that makes these tests clinically meaningful.
The validation approach
Signant's research team designed a rigorous comparison study with 143 healthy volunteers aged 32 to 61. Each volunteer completed a seven-minute battery of attention tests Simple Reaction Time, Digit Vigilance, and Choice Reaction Time using both the original button box system and the new web-based keyboard interface.
The methodology eliminated common validation pitfalls. Randomized design controlled for test order effects. Participants completed two familiarization sessions before testing to account for practice effects. Testing occurred on identical laptops to isolate the input method as the only variable. Even caffeine consumption was controlled, as it can enhance cognitive performance.
The results: precision maintained
Statistical analysis revealed no significant differences between input types. The Power of Attention composite measure combining reaction time from all three attention tests showed mean reaction times of 203.75 milliseconds for the button box system compared to 221.11 milliseconds for the web version.
More importantly, the test-retest reliability remained exceptionally high. The correlation coefficient exceeded 0.94 for both systems with significance levels below 0.0001.
The input device by session interaction showed p=0.2438, confirming that the web-based system maintains consistent performance across repeated testing.
Perhaps most critically for clinical trial applications, the difference between systems does not influence the variability of performance. This means the web-based platform captures the subtle changes in cognition that matter for detecting treatment effects.
Opening new possibilities
This validation enables practical advances in how cognitive assessments reach patients. Web-based delivery supports decentralized trial designs where patients complete assessments at home rather than traveling to research sites.
It makes training on cognitive tests more cost-effective and accessible. It creates opportunities for pre-screening against cognitive norms before formal study enrolment, potentially reducing screen failures and accelerating recruitment.
The CDR System's validated composite measures spanning attention, working memory, and episodic memory domains now become available in flexible deployment models. Sites can choose the right approach for each study design: traditional in-clinic testing, hybrid models, or fully remote administration.
The path to proof
Signant's approach to platform modernization reflects a broader principle: innovation should expand possibilities without compromising the evidence quality that regulatory decisions demand. Web-based cognitive testing represents not just technological convenience but a fundamental enabler of patient-centric trial design.
The CDR System validation demonstrates what's possible when engineering rigor meets clinical needs. Millisecond-level precision. Regulatory-grade reliability. Flexible deployment. These aren't competing priorities they're the foundation for evidence generation at the speed of life.
Helen Brooker is a specialist in cognitive test development and aging, with over 18 years of experience in academic and clinical research. She leverages her expertise in neuropsychological assessment, clinical trial delivery, and digital health solutions as a Senior Product Manager at Signant, where she oversees the company's proprietary computerized cognitive test solution.
Pascal Goetghebeur is an experienced CNS pharmacologist and behavioral scientist specializing in psychiatry and neurodegeneration. At Signant Health, he serves as Clinical Principal for Cognition, Science & Medicine in the Digital Health Sciences division, focusing on the role of cognition in drug development and managing the clinical aspect of Signant’s proprietary cognitive assessment battery.
