Preliminary Feasibility and Validity Data in Older Adults with and without Subjective Cognitive Decline
This blog series shares what’s happening day-to-day in our Innovation Lab. The VeraSci Innovation Lab was created to pair scientific knowledge with cutting-edge technology to improve the tools and measurements available for use in clinical trials.
VeraSci’s Innovation Lab has been investigating use of a wearable and removeable shoe insole to assesses gait and related measures in aging individuals. We recognize that streamlined assessment of gait in real-world settings has the potential for widespread utility in clinical trials across CNS disorders including Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis, among others. We recently presented preliminary findings from an ongoing study at the American Society of Clinical Psychopharmacology (ASCP) 2020 Annual Meeting.
The integration of wearable devices into regulated clinical trials for the assessment of cognition and functioning continues to be a topic of interest. If appropriately implemented, measurements from validated wearable technologies have the potential to revolutionize the conduct of clinical trials by facilitating the development of site-less clinical trial designs. In order to be truly informative, however, endpoints collected by these devices must undergo the same clinical and technological validation process required by other currently accepted tools. This study examines the reliability of industry-grade pressure sensing insoles for the real-time capture of gait measures of older adults, and the relationship between gait measures and standard measures of cognition and functioning.
Participants & Study Design
Recruitment for this study is ongoing. At the time of the analysis, 28 adults age 55 and older had completed the study, including 19 healthy controls and 9 individuals with subjective cognitive decline. Subjective cognitive decline was determined by a total score greater than or equal to 4 on the Cognitive Functional Instrument (CFI). The study design includes:
- A baseline assessment, which involves data collection from the insoles during four standardized walking tests as well as completion of a cognitive test battery
- A one-week period of data collection from the insoles during participants’ daily lives
- A one-week follow-up laboratory assessment, which involves data collection from the insoles during the same four standardized walking tests used during the baseline assessment
Measures, Assessments and Analysis
The study utilized measures of gait, functional capacity, and cognition. The insoles produce measures that characterize a subject’s gait across a gait cycle as well as within the gait cycle, such as the ground force reaction, cycle time, and mean stride length. Functional capacity was assessed using the Virtual Reality Functional Capacity Assessment Tool (VRFCAT). The VRFCAT uses a realistic simulated environment to recreate routine activities of daily living like meal planning and preparation, using transportation for getting places, shopping for groceries, and handling money. Cognition was assessed using the Brief Assessment of Cognition (BAC).
Results & Discussion
The 500-foot walk test generally produced more reliable gait measures than the other walking assessments. The shorter walking tests were considerably more variable. This is consistent with previous findings that the reliability of gait measures increases with longer walking assessments.
Several gait measures significantly correlated (no correction for multiple comparisons) with functional capacity and cognitive measures. Double support time (the time during which both feet are on the floor) and single leg stance duration (time that a given foot was in contact with the ground) were both significantly correlated with the VRFCAT (r=.45 to .54) and with the BAC subtests letter fluency (r=-.48 to -.53) and delayed cued recall (r=-.43 to -.52).
Prior research has demonstrated that older adults with subjective cognitive decline show impaired performance on both functional capacity assessed by the VRFCAT and on objective cognition tasks in the BAC. Older adults with subjective cognitive decline are at increased risk for Alzheimer’s disease. In conjunction with previously reported research, the preliminary results of this ongoing study suggest gait variables may provide sensitive tools for identifying older adults at-risk for developing Alzheimer’s disease and for evaluating responsiveness to treatment.