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Cognitive impairment and driving safety
Accident Analysis and Prevention 49 (2012) 261–262
Contents lists available at SciVerse ScienceDirect
Accident Analysis and Prevention journal homepage: www.elsevier.com/locate/aap
Editorial
Cognitive impairment and driving safety a b s t r a c t As the populations of many countries continue to age, cognitive impairment will likely become more common. Individuals with cognitive impairment pose special challenges for families, health professionals, driving safety professionals, and the larger community, particularly if these older adults depend on driving as their primary means of community mobility. It is vital that we continue to extend our knowledge about the driving behavior of individuals’ with cognitive impairment, as well as try to develop effective means of screening and assessing these individuals for fitness to drive and help facilitate their transition to non-driving when appropriate. This special issue is intended to provide researchers and practitioners an opportunity to present the most recent research findings on driving-related issues among older adults with cognitive impairment. The issue contains 11 original contributions from seven countries. The topics covered by these papers are: crash risks; screening, assessment, and fitness to drive; driving performance using a driving simulator; and driving behaviors and driving-related decisions of people with cognitive impairments. © 2012 Published by Elsevier Ltd.
1. Prolog to special issue Many of the populations around the world are aging. Data suggest that the global proportion of people age 60 and older, which was 8% in 1950 and 11% in 2009, will reach 22% by 2050 (United Nations, 2009). In developed countries, this proportion is expected to be closer to one-third by 2050. As populations continue to age, societies will be faced with increasing numbers of older drivers who may have cognitive impairment, such as dementia. It is estimated that globally, the number of people with dementia will reach more than 81 million by 2040 (Ferri et al., 2005). According to recent estimates for the United States (US) by the Alzheimer’s Association (2011), 13% of people age 65 and older and 43% of people age 85 and older have Alzheimer’s disease (a major cause of age-related cognitive impairment). Individuals with cognitive impairment pose special challenges for families, health professionals, driving safety professionals, and the larger community, particularly if these older adults depend on driving as their primary means of community mobility (Eby and Molnar, 2010). The scope of these challenges is broad. Many people with cognitive impairment continue to drive and there is evidence that overall, these drivers have a two-fold increase in crash risk compared to those without cognitive impairment (Carr and Ott, 2010). However, the level of cognitive impairment that constitutes an unacceptable driving risk remains unknown. Older drivers with cognitive impairment are also likely to lack the insight needed to make appropriate decisions on their own about stopping or restricting their driving in response to cognitive declines. In addition, drivers with diminished cognitive capacity are less likely to benefit from education, training, or vehicle adaptations. Health professionals often have to rely on family members to raise driving-safety concerns and to provide driving safety information. However, not all older drivers 0001-4575/$ – see front matter © 2012 Published by Elsevier Ltd. http://dx.doi.org/10.1016/j.aap.2012.05.035
have family members who are in a position to monitor their driving or support them in moving toward driving retirement. Finally, the same cognitive declines that may cause older adults to give up driving can also make it very difficult to use other community mobility options. Given these challenges, it is vital that we continue to extend our knowledge about the driving behavior of individuals’ with cognitive impairment, as well as try to develop effective means of screening and assessing these individuals for fitness to drive and help facilitate their transition to non-driving when appropriate. As in other areas of traffic safety, a multi-disciplinary and multi-faceted approach will likely yield the most promising results. This special issue is intended to provide researchers and practitioners an opportunity to present the most recent research findings on driving-related issues among older adults with cognitive impairment. This issue contains 11 original contributions from seven countries. Two of the articles address the issue of crash risk, including a discourse on the crash risk of older adults (O’Neill) and a study of crash risk factors for people with traumatic brain injuries (Neyens and Boyle). Three articles address the topics of screening, assessment, and fitness to drive. One of these articles reports on a study examining the validity of a test to assess cognitively impaired drivers relative to whether they are right or left handed (Krishnasamy and Unsworth). The second of these articles presents a comparison of two brief cognitive screening tests in terms of their ability to detect unsafe older drivers (Ferreira, Simões, and Marôco). The third of these articles investigates the predictive value of a cognitive screening test on on-road driving performance among older adults and people with Parkinson’s Disease (Crizzle, Classen, Bédard, Lanford, and Winter). Two articles investigate driving performance using a driving simulator, including a comparison of inconsistencies in several performance
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Editorial / Accident Analysis and Prevention 49 (2012) 261–262
measures between younger and older drivers (Bunce, Young, Blane, and Khugputh) and a study of the driving performance of people with mild cognitive impairment (Devlin, McGillivray, Charlton, Lowndew, and Etienne). Finally, four articles address the driving behaviors and driving-related decisions of people with cognitive impairments. The first study compares the self-reported driving status, behaviors, and intentions to restrict or cease driving among groups of cognitively impaired and unimpaired drivers (Kowalski, Love, Tuokko, MacDonald, Hultsch, and Strauss). The second study explores the relationships among cognitive impairment, driving confidence, and self-regulation of driving (Wong, Smith, and Sullivan). The third study examines self-rated cognitive problems and perceived changes in driving skills, discomfort in driving, and the self-regulation of driving through telephone interviews (Meng and Siren). The final study investigates the driving behaviors of people with early stage dementia through the use of in-vehicle instrumentation of people’s personal vehicle (Eby, Silverstein, Molnar, LeBlanc, and Adler). Collectively, these articles should contribute to a deeper understanding of the driving risks posed by drivers with cognitive impairment, the behaviors they exhibit and the decisions they make on the road, and some of the directions being explored for determining their fitness to drive. Ultimately, it is this kind of knowledge that will pave the way for the development of successful approaches for maintaining safe mobility for this growing population. Acknowledgements The papers in this special issue were greatly improved by the comments of expert reviewers. We thank the following colleagues
who generously provided reviews for papers submitted for this special issue. In alphabetical order they are: Susan Baker, Wiebo Brouwer, Bayliss J. Camp, David Carr, Nicholas Cassavaugh, Samuel George Charlton, Moon Choi, Sherrilene Classen, Elizabeth Dugan, Rita Formisano, Judith Heidebrink, Linda Hunt, Kurt Johansson, Lidia P. Kostyniuk, Suzanne Lee, Jacki Liddle, Thomas M. Meuser, Anita Myers, Brian Ott, Michelle Porter, Matthew Rizzo, AnneKristine Schanke, Loren Staplin, Jan E.B. Törnros, and Ergun Y. Uc. We also thank Dr. Rune Elvik who served as the editor for the article that we personally submitted and the two anonymous reviewers who provided critical feedback on that paper. References Alzheimer’s Association, 2011. 2011 Alzheimer’s Disease Facts and Figures. Alzheimer’s Association, Chicago, IL. Carr, D.B., Ott, B.R., 2010. The older adult driver with cognitive impairment: “it’s a very frustrating life”. Journal of the American Medical Association 303 (16), 1632–1641. Eby, D.W., Molnar, L.J., 2010. Driving fitness and cognitive impairment: issues for physicians. Journal of the American Medical Association 303 (16), 1642–1643. Ferri, C.P., et al., 2005. Global prevalence of dementia: a Delphi consensus study. Lancet 366 (9503), 2112–2117. United Nations, 2009. World Population Aging 2009. United Nations, New York, NY.
David W. Eby Lisa J. Molnar University of Michigan Transportation Research Institute, Michigan Center for Advancing Safe Transportation throughout the Lifespan, 2901 Baxter Rd., Ann Arbor, MI 48109, United States 31 May 2012
Contents lists available at SciVerse ScienceDirect
Accident Analysis and Prevention journal homepage: www.elsevier.com/locate/aap
Editorial
Cognitive impairment and driving safety a b s t r a c t As the populations of many countries continue to age, cognitive impairment will likely become more common. Individuals with cognitive impairment pose special challenges for families, health professionals, driving safety professionals, and the larger community, particularly if these older adults depend on driving as their primary means of community mobility. It is vital that we continue to extend our knowledge about the driving behavior of individuals’ with cognitive impairment, as well as try to develop effective means of screening and assessing these individuals for fitness to drive and help facilitate their transition to non-driving when appropriate. This special issue is intended to provide researchers and practitioners an opportunity to present the most recent research findings on driving-related issues among older adults with cognitive impairment. The issue contains 11 original contributions from seven countries. The topics covered by these papers are: crash risks; screening, assessment, and fitness to drive; driving performance using a driving simulator; and driving behaviors and driving-related decisions of people with cognitive impairments. © 2012 Published by Elsevier Ltd.
1. Prolog to special issue Many of the populations around the world are aging. Data suggest that the global proportion of people age 60 and older, which was 8% in 1950 and 11% in 2009, will reach 22% by 2050 (United Nations, 2009). In developed countries, this proportion is expected to be closer to one-third by 2050. As populations continue to age, societies will be faced with increasing numbers of older drivers who may have cognitive impairment, such as dementia. It is estimated that globally, the number of people with dementia will reach more than 81 million by 2040 (Ferri et al., 2005). According to recent estimates for the United States (US) by the Alzheimer’s Association (2011), 13% of people age 65 and older and 43% of people age 85 and older have Alzheimer’s disease (a major cause of age-related cognitive impairment). Individuals with cognitive impairment pose special challenges for families, health professionals, driving safety professionals, and the larger community, particularly if these older adults depend on driving as their primary means of community mobility (Eby and Molnar, 2010). The scope of these challenges is broad. Many people with cognitive impairment continue to drive and there is evidence that overall, these drivers have a two-fold increase in crash risk compared to those without cognitive impairment (Carr and Ott, 2010). However, the level of cognitive impairment that constitutes an unacceptable driving risk remains unknown. Older drivers with cognitive impairment are also likely to lack the insight needed to make appropriate decisions on their own about stopping or restricting their driving in response to cognitive declines. In addition, drivers with diminished cognitive capacity are less likely to benefit from education, training, or vehicle adaptations. Health professionals often have to rely on family members to raise driving-safety concerns and to provide driving safety information. However, not all older drivers 0001-4575/$ – see front matter © 2012 Published by Elsevier Ltd. http://dx.doi.org/10.1016/j.aap.2012.05.035
have family members who are in a position to monitor their driving or support them in moving toward driving retirement. Finally, the same cognitive declines that may cause older adults to give up driving can also make it very difficult to use other community mobility options. Given these challenges, it is vital that we continue to extend our knowledge about the driving behavior of individuals’ with cognitive impairment, as well as try to develop effective means of screening and assessing these individuals for fitness to drive and help facilitate their transition to non-driving when appropriate. As in other areas of traffic safety, a multi-disciplinary and multi-faceted approach will likely yield the most promising results. This special issue is intended to provide researchers and practitioners an opportunity to present the most recent research findings on driving-related issues among older adults with cognitive impairment. This issue contains 11 original contributions from seven countries. Two of the articles address the issue of crash risk, including a discourse on the crash risk of older adults (O’Neill) and a study of crash risk factors for people with traumatic brain injuries (Neyens and Boyle). Three articles address the topics of screening, assessment, and fitness to drive. One of these articles reports on a study examining the validity of a test to assess cognitively impaired drivers relative to whether they are right or left handed (Krishnasamy and Unsworth). The second of these articles presents a comparison of two brief cognitive screening tests in terms of their ability to detect unsafe older drivers (Ferreira, Simões, and Marôco). The third of these articles investigates the predictive value of a cognitive screening test on on-road driving performance among older adults and people with Parkinson’s Disease (Crizzle, Classen, Bédard, Lanford, and Winter). Two articles investigate driving performance using a driving simulator, including a comparison of inconsistencies in several performance
262
Editorial / Accident Analysis and Prevention 49 (2012) 261–262
measures between younger and older drivers (Bunce, Young, Blane, and Khugputh) and a study of the driving performance of people with mild cognitive impairment (Devlin, McGillivray, Charlton, Lowndew, and Etienne). Finally, four articles address the driving behaviors and driving-related decisions of people with cognitive impairments. The first study compares the self-reported driving status, behaviors, and intentions to restrict or cease driving among groups of cognitively impaired and unimpaired drivers (Kowalski, Love, Tuokko, MacDonald, Hultsch, and Strauss). The second study explores the relationships among cognitive impairment, driving confidence, and self-regulation of driving (Wong, Smith, and Sullivan). The third study examines self-rated cognitive problems and perceived changes in driving skills, discomfort in driving, and the self-regulation of driving through telephone interviews (Meng and Siren). The final study investigates the driving behaviors of people with early stage dementia through the use of in-vehicle instrumentation of people’s personal vehicle (Eby, Silverstein, Molnar, LeBlanc, and Adler). Collectively, these articles should contribute to a deeper understanding of the driving risks posed by drivers with cognitive impairment, the behaviors they exhibit and the decisions they make on the road, and some of the directions being explored for determining their fitness to drive. Ultimately, it is this kind of knowledge that will pave the way for the development of successful approaches for maintaining safe mobility for this growing population. Acknowledgements The papers in this special issue were greatly improved by the comments of expert reviewers. We thank the following colleagues
who generously provided reviews for papers submitted for this special issue. In alphabetical order they are: Susan Baker, Wiebo Brouwer, Bayliss J. Camp, David Carr, Nicholas Cassavaugh, Samuel George Charlton, Moon Choi, Sherrilene Classen, Elizabeth Dugan, Rita Formisano, Judith Heidebrink, Linda Hunt, Kurt Johansson, Lidia P. Kostyniuk, Suzanne Lee, Jacki Liddle, Thomas M. Meuser, Anita Myers, Brian Ott, Michelle Porter, Matthew Rizzo, AnneKristine Schanke, Loren Staplin, Jan E.B. Törnros, and Ergun Y. Uc. We also thank Dr. Rune Elvik who served as the editor for the article that we personally submitted and the two anonymous reviewers who provided critical feedback on that paper. References Alzheimer’s Association, 2011. 2011 Alzheimer’s Disease Facts and Figures. Alzheimer’s Association, Chicago, IL. Carr, D.B., Ott, B.R., 2010. The older adult driver with cognitive impairment: “it’s a very frustrating life”. Journal of the American Medical Association 303 (16), 1632–1641. Eby, D.W., Molnar, L.J., 2010. Driving fitness and cognitive impairment: issues for physicians. Journal of the American Medical Association 303 (16), 1642–1643. Ferri, C.P., et al., 2005. Global prevalence of dementia: a Delphi consensus study. Lancet 366 (9503), 2112–2117. United Nations, 2009. World Population Aging 2009. United Nations, New York, NY.
David W. Eby Lisa J. Molnar University of Michigan Transportation Research Institute, Michigan Center for Advancing Safe Transportation throughout the Lifespan, 2901 Baxter Rd., Ann Arbor, MI 48109, United States 31 May 2012