Abstract

Introduction

Older drivers are at an elevated risk for crashes per mile driven due in part to declining sensory, cognitive and psychomotor abilities. Such declining abilities result from age-related medical conditions and/or the medications used to treat them. To improve the safe mobility of older adults, better information is needed about their driving exposure and patterns (i.e., when, where, and under what conditions they drive), and how these driving behaviors are affected by declines in abilities. Hearing is one area of functional decline receiving increased research attention. There is growing interest in not only how hearing impairment alone affects driving behavior but also how hearing impairment interacts with other forms of impairment, especially cognitive and visual impairment, to affect driving. This study examines the effects of hearing impairment, alone and in combination with cognitive and/or visual impairment, on the driving exposure and patterns of study participants, as measured by GPS/datalogger data.

Key Findings

• Passing an objective hearing test in both ears (not having a hearing impairment) was significantly associated with driving a higher percentage of trips at night, on high-speed roads, and in rush-hour traffic.
• Passing the hearing test in both ears was significantly associated with driving a lower percentage of trips greater than 15 miles from home.
• Better vision was significantly associated with driving a higher percentage of trips more than 15 miles from home.
• Better cognition was significantly associated with driving at night, on high-speed roads, and during rush hour.
• Those with good hearing in both ears (compared with those with poor hearing in both ears) drove more trips during rush hour as cognition increased.
• Those with good hearing in only one ear drove fewer rush-hour trips as cognition increased, compared with those who had bad hearing in both ears.

Methodology

Data came from 2,046 participants in the AAA LongROAD study. The AAA LongROAD study is a multisite prospective cohort study of drivers enrolled in five sites in the U.S. (Ann Arbor, MI; Baltimore, MD; Cooperstown, NY; Denver, CO; and San Diego, CA). Participants from the New York site were not included in the analysis because of differences in how this site administered the visual acuity test. Study participants were between 65 and 79 years of age at enrollment. Data for this study were collected from questionnaires assessing various aspects of driving and functioning, in-person clinical assessments conducted by research staff, and objective driving measures derived from GPS/datalogger data following procedures described in previous research. Questionnaire and in-person assessment data for the current analysis came from a single point in time at baseline, but the driving data were collected continuously throughout the study. To account for differences in exposure and seasonality, the analysis only included participants’ first 12 months of driving, with the GPS variables averaged across the 12-month period.

Results

Results presented in this research brief provide practical insights on the role of hearing impairment in driving exposure and patterns. Findings suggest that hearing should be taken into account in assessing the driving of older adults and developing strategies to keep them safe. Specifically, testing for hearing impairment should be a standard part of driver assessment. In addition, educating older adults about the potential effects of hearing impairment, both alone and in combination with visual and/or cognitive impairment, should be part of education and training programs to help them maintain safe driving and mobility.