Candrive-Development of a Risk Stratification Tool for Older Drivers.

BACKGROUND: Assessing an older adult's fitness-to-drive is an important part of clinical decision making. However, most existing risk prediction tools only have a dichotomous design, which does not account for subtle differences in risk status for patients with complex medical conditions or changes over time. Our objective was to develop an older driver risk stratification tool (RST) to screen for medical fitness-to-drive in older adults. METHODS: Participants were active drivers aged 70 and older from 7 sites across 4 Canadian provinces. They underwent in-person assessments every 4 months with an annual comprehensive assessment. Participant vehicles were instrumented to provide vehicle and passive Global Positioning System (GPS) data. The primary outcome measure was police-reported, expert-validated, at-fault collision adjusted per annual kilometers driven. Predictor variables included physical, cognitive, and health assessment measures. RESULTS: A total of 928 older drivers were recruited for this study beginning in 2009. The average age at enrollment was 76.2 (standard deviation [SD] = 4.8) with 62.1% male participants. The mean duration for participation was 4.9 (SD = 1.6) years. The derived Candrive RST included 4 predictors. Out of 4 483 person-years of driving, 74.8% fell within the lowest risk category. Only 2.9% of person-years were in the highest risk category where the relative risk for at-fault collisions was 5.26 (95% confidence interval = 2.81-9.84) compared to the lowest risk group. CONCLUSIONS: For older drivers whose medical conditions create uncertainty regarding their fitness-to-drive, the Candrive RST may assist primary health care providers when initiating a conversation about driving and to guide further evaluation.

Self-reported violations, errors and lapses for older drivers: Measuring the change in frequency of aberrant driving behaviours across five time-points.

The current study aimed to: 1. to confirm the 21-item, three-factor Driver Behaviour Questionnaire (DBQ) structure suggested by Koppel et al. (2018) within an independent sample of Canadian older drivers; 2. to examine whether the structure of the DBQ remained stable over a four-year period; 3. to conduct a latent growth analysis to determine whether older drivers' DBQ scores changed across time. Five hundred and sixty Canadian older drivers (males = 61.3%) from the Candrive/Ozcandrive longitudinal study completed the DBQ yearly for four years across five time-points that were approximately 12 months apart. In Year 1, the average age of the older drivers was 76.0 years (SD = 4.5 years; Range = 70-92 years). Findings from the study support the 21-item, three-factor DBQ structure suggested by Koppel and colleagues for an Australian sample of older drivers as being acceptable in an independent sample of Canadian older drivers. In addition, Canadian older drivers' responses to this version of the DBQ were stable across the five time-points. More specifically, there was very little change in older drivers' self-reported violations, and no significant change for self-reported errors or lapses. The findings from the current study add further support for this version of the DBQ as being a suitable tool for examining self-reported aberrant driving behaviours in older drivers. Future research should investigate the relationship between older drivers' self-reported aberrant driving behaviours and their performance on functional measures, their responses to other driving-related abilities and practice scales and/or questionnaires, as well their usual (or naturalistic) driving practices and/or performance on on-road driving tasks.

Attitudes: Mediators of the Relation between Health and Driving in Older Adults.

We examined the relations between perceived health (e.g., self-perceived health status) and driving self-regulatory practices (e.g., frequency of driving, avoiding challenging driving situations) as mediated by driving attitudes and perceptions (i.e., driving comfort, positive and negative attitudes towards driving) in data collected for 928 drivers aged 70 and older enrolled in the Candrive II study. We observed that specific attitudes towards driving (e.g., driving comfort, negative attitudes towards driving) mediate the relations between health symptoms and self-regulatory driving behaviours at baseline and over time. Only negative attitudes towards driving fully mediated the relationships between changes in perceived health symptoms and changes in driving behavior. Perceived health symptoms apparently influence the likelihood of avoiding challenging driving situations through both initial negative attitudes towards driving as well as changes in negative attitudes over time. Understanding influences on self-regulatory driving behaviours will be of benefit when designing interventions to enhance the safety of older drivers.

CIHR Candrive Cohort Comparison with Canadian Household Population Holding Valid Driver's Licenses.

We investigated whether convenience sampling is a suitable method to generate a sample of older drivers representative of the older-Canadian driver population. Using equivalence testing, we compared a large convenience sample of older drivers (Candrive II prospective cohort study) to a similarly aged population of older Canadian drivers. The Candrive sample consists of 928 community-dwelling older drivers from seven metropolitan areas of Canada. The population data was obtained from the Canadian Community Health Survey - Healthy Aging (CCHS-HA), which is a representative sample of older Canadians. The data for drivers aged 70 and older were extracted from the CCHS-HA database, for a total of 3,899 older Canadian drivers. Two samples were demonstrated as equivalent on socio-demographic, health, and driving variables that we compared, but not on driving frequency. We conclude that convenience sampling used in the Candrive study created a fairly representative sample of Canadian older drivers, with a few exceptions.

Psychosocial Constructs as Possible Moderators of Self-Reported Driving Restrictions.

To date, associations between psychosocial driving variables and behaviour have been examined only cross-sectionally. Using three waves of data collected annually from 928 older drivers (mean age = 76.21 years; 62% male) enrolled in the Candrive II cohort, we examined in this study whether changes in attitudes and perceptions towards driving (decisional balance and day and night driving comfort) were associated with changes in older adults' reported restrictions in driving practices and perceived driving abilities. Multi-level models revealed that older adults who showed an increase in negative attitudes towards driving over time were more likely to report more-restricted practices (greater avoidance of challenging driving situations) and perceived declines in driving abilities compared to individuals whose attitudes towards driving remained stable across two years. This work supports previous findings and offers a new understanding of how attitudes relate to driving perceptions (e.g., comfort) and self-regulation in older adults over time.

Cognitive Performance, Driving Behavior, and Attitudes over Time in Older Adults.

We hypothesized that changes over time in cognitive performance are associated with changes in driver perceptions, attitudes, and self-regulatory behaviors among older adults. Healthy older adults (n = 928) underwent cognitive assessments at baseline with two subsequent annual follow-ups, and completed scales regarding their perceptions, attitudes, and driving behaviours. Multivariate analysis showed small but statistically significant relationships between the cognitive tests and self-report measures, with the largest magnitudes between scores on the Trails B cognitive task (seconds), perceptions of driving abilities (ß = -0.32), and situational driving avoidance (ß = 0.55) (p < 0.05). Cognitive slowing and executive dysfunction appear to be associated with modestly lower perceived driving abilities and more avoidance of driving situations over time in this exploratory analysis.

Measuring Driving-Related Attitudes Among Older Adults: Psychometric Evidence for the Decisional Balance Scale Across Time and Gender.

PURPOSE OF THE STUDY: The Decisional Balance Scale (DBS) was developed to assess older adults' attitudes related to driving and includes both intrapersonal and interpersonal motivations for driving. This study examined the psychometric properties of the DBS ratings across 3 time points in a sample of 928 older drivers who participated in the Canadian Driving Research Initiative for Vehicular Safety in the Elderly (Candrive). DESIGN AND METHODS: Measurement invariance of the DBS was assessed longitudinally and across gender. RESULTS: Confirmatory factor analyses revealed that a two-factor model (positive and negative attitudes) for both driving beliefs related to the self and other provided a good fit to the data at each time point. Measurement invariance was supported across time and gender. Significant associations between the DBS factor scores and other driving measures (e.g., perceived driving ability and self-regulatory driving practices) provided evidence of convergent validity. IMPLICATIONS: The DBS appears to be a robust instrument for measuring attitudes toward driving and is recommended for continued use in future research on driving behaviors with older adults.

When it is time to hang up the keys: the driving and dementia toolkit - for persons with dementia (PWD) and caregivers - a practical resource.

BACKGROUND: The aim of this project was to develop a toolkit to assist persons with dementia (PWD) and their caregivers, in planning for retirement from driving. The information gathered was used to develop a tool that can assist reflection about, and make sound decisions in this challenging area of the dementia journey. The purpose is to keep safe drivers on the road and to prepare those who are moving towards being at risk of being involved in crashes, to eventually stop driving when they are unsafe.The toolkit was prepared to address the concerns of both the PWD as well as the caregivers. Strategies and solutions are presented for both the PWD and the caregivers. A grief insert was also developed that can assist caregivers in supporting the PWD in the grief process that can accompany losing one's driving privileges.

The Candrive/Ozcandrive prospective older driver study: Methodology and early study findings.

Although the vast majority of active, older drivers are safe drivers, health conditions and related functional declines associated with increasing age can affect driving ability. This is a concern for older drivers, their families, and the public, as well as government agencies. To address these issues, the Canadian Institutes of Health Research (CIHR) Team in Driving in Older Persons (Candrive II) Research Program was funded in 2008 to create a prospective cohort of older active drivers to be followed for several years. In 2009 an Australian collaboration (Ozcandrive) joined the project funded by an Australian Research Council (ARC) Linkage Grant. This special issue describes the preliminary findings of the Candrive/Ozcandrive prospective study of 1300 older drivers in Canada, Australia and New Zealand. The methodology for the study, description of the cohort and findings related to older driver health and effects on driving, as well as the utility of some existing older driver assessment tools used on this population, are described. Future findings from this ongoing study will lead to insights into older driver safety and tools that will ideally help keep older drivers safely on the road.

Reprint of "Driving avoidance by older adults: Is it always self-regulation?".

Self-regulation shows promise as a means by which older adults can continue to drive at some level without having to stop altogether. Self-regulation is generally described as the process of modifying or adjusting one's driving patterns by driving less or intentionally avoiding driving situations considered to be challenging, typically in response to an awareness that driving skills have declined. However, most studies asking older adults whether they avoid certain driving situations or have reduced the amount of driving they do under certain circumstances have not delved deeper into the motivations for such avoidance or driving reduction. There are many reasons for modifying driving that have nothing to do with self-regulation, such as no longer needing to take trips at certain times of day because of changes in preferences or lifestyles. The purpose of this study was to examine self-regulatory practices among older adults at multiple levels of driver performance and decision making, taking into account the specific motivations for avoiding particular driving situations or engaging in other driving practices. Study participants completed a computer-based questionnaire on driving self-regulation. Results suggest that self-regulation is a complex process that cannot be defined simply by the reported driving modifications made by drivers. Understanding the motivations for these behaviors is necessary and the study showed that they are varied and differ considerably across driving situations. Reasons for driving avoidance or other practices were often more closely related to lifestyle or preferences than to self-regulation. Based on these findings, three distinct groups were identified with regard to whether and for what reasons participants modified their driving.

The Canadian Safe Driving Study-Phase I pilot: Examining potential logistical barriers to the full cohort study.

Multiple organizations and task forces have called for a reliable and valid method to identify older drivers who are medically unfit to drive. The development of a clinical decision rule for this type of screening requires data from a longitudinal prospective cohort of older drivers. The aim of this article is to identify potential design, sampling and data collection barriers to such studies based on an analysis of the Canadian Safe Driving Study-phase I pilot (Candrive I). A convenience sample of 100 active older drivers aged 70 years or more was recruited through the aid of a seniors' organization, 94 of whom completed the full study (retention rate 94%). Data were collected over the course of 1 year on various driving behaviours, as well as on cognitive, physical and mental functioning. Driving patterns were recorded using driving diaries, logs and electronic devices. Driving records from the Ministry of Transportation of Ontario (MTO) were obtained for the 3-year period preceding the study initiation and up to 1 year following study completion. An increased burden of illness was observed as the number of medical diagnoses and medication use increased over the study period. Study participants were involved in a total of five motor vehicle collisions identified through MTO records, which was comparable to the Ontario annual collision rate of 4.1% for drivers aged 75 years or older. In sum, many of the relevant logistical and practical barriers to studying a large sample of older drivers longitudinally have been shown to be addressable, supporting the feasibility of completing a large prospective cohort study of older drivers.

Driving avoidance by older adults: is it always self-regulation?

Self-regulation shows promise as a means by which older adults can continue to drive at some level without having to stop altogether. Self-regulation is generally described as the process of modifying or adjusting one's driving patterns by driving less or intentionally avoiding driving situations considered to be challenging, typically in response to an awareness that driving skills have declined. However, most studies asking older adults whether they avoid certain driving situations or have reduced the amount of driving they do under certain circumstances have not delved deeper into the motivations for such avoidance or driving reduction. There are many reasons for modifying driving that have nothing to do with self-regulation, such as no longer needing to take trips at certain times of day because of changes in preferences or lifestyles. The purpose of this study was to examine self-regulatory practices among older adults at multiple levels of driver performance and decision making, taking into account the specific motivations for avoiding particular driving situations or engaging in other driving practices. Study participants completed a computer-based questionnaire on driving self-regulation. Results suggest that self-regulation is a complex process that cannot be defined simply by the reported driving modifications made by drivers. Understanding the motivations for these behaviors is necessary and the study showed that they are varied and differ considerably across driving situations. Reasons for driving avoidance or other practices were often more closely related to lifestyle or preferences than to self-regulation. Based on these findings, three distinct groups were identified with regard to whether and for what reasons participants modified their driving.

It is premature to test older drivers with the SIMARD-MD.

BACKGROUND: A new tool, the SIMARD-MD, has been proposed to help physicians identify cognitively impaired drivers who may be unfit to drive, but little empirical evidence is available to justify its use. We analyzed data from a cohort of older Canadian drivers who had undergone cognitive testing to: (1) correlate the SIMARD-MD with other tools that measure cognition (e.g., trail-making test), (2) identify how many drivers, using published cut-offs on the SIMARD-MD, would be recommended to lose their license, or be considered fit to drive, or be required to undergo further driving assessment, and (3) determine if the SIMARD-MD is biased by level of education as many cognitive tools are. METHODS: Cross-sectional data from 841 drivers aged 70 and over from seven Canadian sites who are enrolled in a 5-year cohort study were used for the analyses. Scores on the SIMARD-MD were correlated with scores on the other cognitive measures. The recommendations that would be made based on the SIMARD-MD scores were based on published cut-off values suggested by the authors of the tool. The impact of education status was examined using linear regression controlling for age. RESULTS: Correlations between the SIMARD-MD and other cognitive measures ranged from .15 to .86. Using published cut-off scores, 21 participants (2.5%) would have been recommended to relinquish their licenses, 428 (50.9%) would have been deemed fit to drive, and 392 (46.6%) would have been required to undergo further testing. We found a difference of 8.19 points (95% CI=4.99, 11.40, p<.001) in favor of drivers with post-secondary education versus those without, representing over 11% of the mean score. DISCUSSION: The SIMARD-MD is unlikely to be valuable to clinicians because it lacks sufficient precision to provide clear recommendations about fitness-to-drive. Recommendations based solely on the SIMARD-MD may place many seniors at risk of losing their transportation mobility or incurring unnecessary stress and costs to prove they are safe to drive. Furthermore, the education bias may create an unwanted structural inequity. Hence, adoption of the SIMARD-MD as a tool to determine fitness-to-drive appears premature.

Determining the validity of the AMA guide: A historical cohort analysis of the assessment of driving related skills and crash rate among older drivers.

BACKGROUND: Chronic health conditions associated with ageing can lead to changes in driving ability. The Canadian Driving Research Initiative for Vehicular Safety in the Elderly (Candrive II) is a 5-year prospective study funded by the Canadian Institutes of Health Research aiming to develop an in-office screening tool that will help clinicians identify potentially at-risk older drivers. Currently, no tools exist to directly predict the risk of motor vehicle collision (MVC) in this population. The American Medical Association (AMA), in collaboration with the National Highway Traffic Safety Association, has designed an opinion-based guide for assessing medical fitness to drive in older adults and recommends that physicians use the Assessment of Driving Related Skills (ADReS) as a test battery to measure vision, cognition and motor/somatosensory functions related to driving. The ADReS consists of the Snellen visual acuity test, visual fields by confrontation test, Trail Making Test part B, clock drawing test, Rapid Pace Walk, and manual tests of range of motion and motor strength. We used baseline data from the Candrive/Ozcandrive common cohort of older drivers to evaluate the validity of the ADReS subtests. We hypothesized that participants who crashed in the 2 years before the baseline assessment would have poorer scores on the ADReS subtests than participants who had not crashed. METHODS: In the Candrive/Ozcandrive study, 1230 participants aged 70 years or older were recruited from 7 Canadian cities, 1 Australian city and 1 New Zealand city, all of whom completed a comprehensive clinical assessment at study entry. The assessment included all tests selected as part of the ADReS. For this historical cohort study, data on all crashes (at-fault and non-at-fault) that occurred within 2 years preceding the baseline assessment were obtained from the respective licensing jurisdictions. Those who crashed were compared to those who had not crashed on their ADReS subtest scores using Pearson's chi-squared test and Student's t-test. RESULTS: Sixty-three of the 1230 participants (5.1%) were involved in an MVC within the 2 years preceding the baseline assessment. Contrary to our hypothesis, there were no statistically significant associations between abnormal performance on the tests constituting the ADReS and history of crash in the previous 2 years (p>0.01). DISCUSSION: We found that a history of crash in the previous 2 years was not associated with abnormalities on the subtests comprising the ADReS. This suggests the need for prospective analyses of risk factors over time to establish sensitive, valid predictors of crash that can be incorporated in clinical practice guidelines.

The relationship between cognitive performance, perceptions of driving comfort and abilities, and self-reported driving restrictions among healthy older drivers.

The objective of the present study was to examine the relationship between cognitive performance, driver perceptions and self-reported driving restrictions. A cross-sectional analysis was conducted on baseline data from Candrive II, a five-year prospective cohort study of 928 older drivers aged 70-94 years from seven cities. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) as well as the Trail Making Test, parts A and B. Driver perceptions were assessed using the Day and Night Driving Comfort Scales and the Perceived Driving Abilities scale, while driving practices were captured by the Situational Driving Frequency and Avoidance scales, as well as the Driving Habits and Intentions Questionnaire. The baseline data indicates this cohort is largely a cognitively intact group. Univariate regression analysis showed that longer Trails A and B completion times were significantly, but only modestly associated with reduced driving frequency and perceived driving abilities and comfort, as well as a significant tendency to avoid more difficult driving situations (all p<.05). Most of these associations persisted after adjusting for age and sex, as well as indicators of health, vision, mood and physical functioning. Exceptions were Trails A and B completion times and situational driving frequency, as well as time to complete Trails B and current driving restrictions. After adjusting for the confounding factors, the total MoCA score was not associated with any of the driving measure scores while the number of errors on Trails A was significantly associated only with situational driving frequency and number of errors on Trails B was significantly associated only with situational driving avoidance. Prospective follow-up will permit examination of whether baseline cognition or changes in cognition are associated with changes in driver perceptions, actual driving restrictions and on-road driving outcomes (e.g., crashes, violations) over time.

Protocol for Candrive II/Ozcandrive, a multicentre prospective older driver cohort study.

The Candrive II/Ozcandrive study, a multicentre prospective cohort study examining the predictive validity of tools for assessing fitness to drive, aims to develop an in-office screening tool that will help clinicians identify older drivers who may be unsafe to drive. This paper describes the study protocol. We are following a cohort of drivers aged ≥70 years for up to 4 years. Starting in 2009, 928 participants have been recruited in seven cities in four Canadian provinces, as well as 302 participants in two sites in Melbourne, Australia and Wellington, New Zealand. Participants underwent a comprehensive assessment at baseline and repeat the assessment yearly thereafter, as well as a brief follow-up assessment at 4 and 8 months each year. A recording device is installed in participants' vehicles to assess driving patterns, and driving records are obtained from licensing authorities to determine the outcomes: at-fault crashes per kilometre driven and violations. To date, the protocol has been generally well adhered to, with 1230 participants, and barriers and challenges are being addressed, as necessary. The Candrive II/Ozcandrive study is unique owing to its size, duration, partnerships with Canadian, Australian and New Zealand stakeholders, and international research collaboration.

Findings from the Candrive/Ozcandrive study: Low mileage older drivers, crash risk and reduced fitness to drive.

Previous research has found that only older drivers with low annual driving mileages had a heightened crash risk relative to other age groups. These drivers tend to drive mainly in urban areas, where the prevalence of complex traffic situations increases crash risk. However it might also be that some drivers may have reduced their driving due to perceived or actual declines in driving fitness. This paper uses Canadian and Australian data from the Candrive/Ozcandrive older driver study to investigate the association between annual driving distances and a set of driving-related factors, including fitness to drive. All drivers in the Candrive/Ozcandrive older driver cohort study were allocated to one of three groups according to their self-reported annual driving distances: <5001km; >5000 and <15,000km; and 15,000km or greater. Relationships between these driving-distance categories and: (a) self-reported crash data; (b) various Year 1 'fitness to drive' performance measures; and (c) self-perceptions of driving ability and of comfort while driving, were determined. Results confirmed the previously reported association between low mileage and heightened crash risk. Further, low mileage drivers performed relatively poorly on a wide range of performance measures, perceived their own driving ability as lower, and reported lower comfort levels when driving in challenging situations, compared to the higher mileage drivers. In most instances, these differences were statistically significant. The paper provides further evidence that the so-called 'older driver problem' is most pertinent to low mileage drivers, and that this is due in part to low mileage drivers tending to have reduced fitness to drive. This higher risk group represented a fairly small proportion of the sample in this study.

The impact of subclinical sleep problems on self-reported driving patterns and perceived driving abilities in a cohort of active older drivers.

The present study sought to investigate the influence of subclinical sleep disturbances on driving practices and driver perceptions in a large cohort of healthy older drivers. Participants from the Candrive II prospective cohort study were investigated. Self-reported measures of sleep problems were used to determine the influence of sleep disturbance on self-reported driving practices and perceived driving abilities, as measured by the Situational Driving Frequency, Situational Driving Avoidance, and Perceived Driving Abilities scales. Hierarchical regression analyses were used to estimate whether mild self-reported sleep problems were predictive of driving restrictions and perceived abilities, while controlling for a variety of health-related factors and demographic variables known to mediate sleep problems or to impact driving. Cross-sectional analysis of baseline data from the Candrive II study suggests that subclinical sleep problems do not significantly influence self-reported driving patterns or perceived driving abilities in older drivers once control variables are considered. The relationship between sleep problems, driving frequency, avoidance and perceived abilities is better explained by mediating demographic, health, and cognitive factors. Further research examining sleep disturbances and driving should include objective measures of driving practices (exposure, patterns) and outcomes (crashes, violations) and should take in consideration the severity of sleep problems.

Associations between age, gender, psychosocial and health characteristics in the Candrive II study cohort.

The relations among driving-related psychosocial measures (e.g., driving comfort, attitudes toward driving) and measures of self-reported health were examined in the context of driver characteristics (i.e., age and gender) within the Canadian Driving Research Initiative for Vehicular Safety in the Elderly (Candrive II) baseline data, available for the cohort of 928 drivers, 70 years of age and older. Older members of the cohort had lower comfort scores and poorer perceptions of their driving abilities. Men reported significantly higher levels of driving comfort than women. When analyses including health were controlled for age and gender, significant relations with health status were evident for most of the psychosocial measures. These findings extend previous research and suggest that attitudes, beliefs, and perceptions about driving may be influenced by health status and act as mediators in the self-regulation process.

Stability of physical assessment of older drivers over 1 year.

Older adults represent the fastest-growing population of drivers with a valid driver's licence. Also common in this age group are multiple chronic medical conditions that may have an effect on physical function and driving ability. Determining the reliability of physical measures used to assess older drivers' functional ability is important to identifying those who are safe to continue driving. Most previous reliability studies of clinical physical measures of health used test-retest intervals shorter than those between patient visits with a clinician. In the present study we examined a more clinically representative interval of 1 year to determine the stability of commonly used physical measures collected during the Candrive II prospective cohort study of older drivers. Reliability statistics indicate that the sequential finger-thumb opposition, rapid pace walk and the Pelli-Robson contrast sensitivity tests have adequate stability over 1 year. Poor stability was observed for the one-legged stance and Snellen visual acuity test. Several assessments with nominal data (Marottoli method [functional neck range of motion], whispered voice test, range of motion and strength testing) lacked sufficient variability to conduct reliability analyses; however, a lack of variability between test days suggests consistency over a 1-year time frame. Our results provide evidence that specific physical measures are stable in monitoring functional ability over the course of a year.