Using the A/T/N Framework to Examine Driving in Preclinical AD.

Monique Williams,Catherine Roe,Beau Ances,Tammie Benzinger,Sarah Stout,John Morris,David Carr,Anne Fagan,David Holtzman,Ganesh Babulal

doi:10.3390/geriatrics3020023

Abstract

The A/T/N classification system is the foundation of the 2018 NIA-AA Research Framework and is intended to guide the Alzheimer disease (AD) research agenda for the next 5–10 years. Driving is a widespread functional activity that may be particularly useful in investigation of functional changes in pathological AD before onset of cognitive symptoms. We examined driving in preclinical AD using the A/T/N framework and found that the onset of driving difficulties is most associated with abnormality of both amyloid and tau pathology, rather than amyloid alone. These results have implications for participant selection into clinical trials and for the application time of interventions aimed at prolonging the time of safe driving among older adults with preclinical AD.

Highlights

By 2050, the United States will face a significant increase in the older adult population, a higher prevalence of Alzheimer disease (AD) and a related increase in older drivers (1 in 4 drivers) [1,2]
This framework predicted time to onset of objectivelymeasured driving problems on a standardized road test when only AD, AD pathology and normal groups were considered
We found that the onset of driving difficulties is most associated with abnormality of both amyloid and tau pathology, rather than amyloid alone

Summary

Introduction

By 2050, the United States will face a significant increase in the older adult population (age > 65 years), a higher prevalence of Alzheimer disease (AD) and a related increase in older drivers (1 in 4 drivers) [1,2]. While age-related changes (e.g., cataracts, reduced reaction time) is a risk factor for driving decline, AD is an important risk factor for higher crash risk and resulting injury and mortality [3,4,5]. Prior work has shown that cognitively normal older adults with preclinical AD make more errors and are faster to receive a marginal or fail rating on a standardized road test compared to those without preclinical AD [7,8]. While past research has used a dichotomous classification of biomarker status (higher vs lower) coupled with cognitive status, this study employed the A/T/N classification system. Geriatrics 2018, 3, 23 to examine the relationship between AD biomarkers and driving performance as evaluated on a standardized road test [7,8].

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Conclusion