Medication use and driving patterns in older drivers: preliminary findings from the LongROAD study

Association between polypharmacy and hard braking events in older adult drivers

BACKGROUND

Polypharmacy (i.e., simultaneous use of two or more medications) poses a serious safety concern for older drivers. This study assesses the association between polypharmacy and hard braking events in older adult drivers.

METHODS

Data for this study came from a naturalistic driving study of 2990 older adults. Information about medications was collected through the "brown-bag review" method. Primary vehicles of the study participants were instrumented with data recording devices for up to 44 months. Multivariable negative binomial model was used to estimate the adjusted incidence rate ratios (aIRRs) and 95 % confidence intervals (CIs) of hard-braking events (i.e., maneuvers with linear deceleration rates ≥0.4 g) associated with polypharmacy.

RESULTS

Of the 2990 participants, 2872 (96.1 %) were eligible for this analysis. At the time of enrollment, 157 (5.5 %) drivers were taking fewer than two medications, 904 (31.5 %) were taking 2-5 medications, 895 (31.2 %) were taking 6-9 medications, 571 (19.9 %) were taking 10-13 medications, and 345 (12.0 %) were taking 14 or more medications. Compared to drivers using fewer than two medications, the risk of hard-braking events increased 8 % (aIRR 1.08, 95 % CI 1.04, 1.13) for users of 2-5 medications, 12 % (aIRR 1.12, 95 % CI 1.08, 1.16) for users of 6-9 medications, 19 % (aIRR 1.19, 95 % CI 1.15, 1.24) for users of 10-13 medications, and 34 % (aIRR 1.34, 95 % CI 1.29, 1.40) for users of 14 or more medications.

CONCLUSIONS

Polypharmacy in older adult drivers is associated with significantly increased incidence of hard-braking events in a dose-response fashion. Effective interventions to reduce polypharmacy use may help improve driving safety in older adults.

Somatic Factors Predict On-Road Driving Skills in Older Drivers and Drivers with Mild Cognitive Impairment

BACKGROUND

On-road driving skills can be impaired in older drivers and drivers with mild cognitive impairment (MCI) due to different driving-relevant deficits. Among these deficits, somatic factors have received little attention so far.

METHODS

In a prospective observational on-road driving study, we examined whether somatic factors can predict on-road driving skills in a mixed sample of healthy older drivers and drivers with MCI (n = 99) and whether the inclusion of age explains additional variance. Somatic factors included the number of prescribed drugs, visual acuity, peripheral visual field integrity, mobility of the cervical spine, and hearing impairment. A hierarchical regression analysis was used to predict on-road driving skills by adding the somatic factors in the first step and age in the second step.

RESULTS

Results revealed that the combination of somatic factors significantly predicted on-road driving skills (R2adjusted = 0.439). The inclusion of age led to a significant increase of explained variance (R2adjusted = 0.466).

CONCLUSIONS

Our results suggest that somatic factors can accurately predict on-road driving skills in healthy older drivers and drivers with MCI. In addition, our results suggest that there is a significant but rather small effect of age beyond somatic changes.

Migraine headaches are associated with motor vehicle crashes and driving habits among older drivers: Prospective cohort study

BACKGROUND

Migraine headache is common in older adults, often causing symptoms that may affect driving safety. This study examined associations of migraine with motor vehicle crashes (MVCs) and driving habits in older drivers and assessed modification of associations by medication use.

METHODS

In a multi-site, prospective cohort study of active drivers aged 65-79 (53% female), we assessed prevalent migraine (i.e., ever had migraine, reported at enrollment), incident migraine (diagnosis first reported at a follow-up visit), and medications typically used for migraine prophylaxis and treatment. During 2-year follow-up, we recorded self-reported MVCs and measured driving habits using in-vehicle GPS devices. Associations of prevalent migraine with driving outcomes were estimated in multivariable mixed models. Using a matched design, associations of incident migraine with MVCs in the subsequent year were estimated with conditional logistic regression. Interactions between migraine and medications were tested in all models.

RESULTS

Of 2589 drivers, 324 (12.5%) reported prevalent migraine and 34 (1.3%) incident migraine. Interactions between migraine and medications were not statistically significant in any models. Prevalent migraine was not associated with MVCs in the subsequent 2 years (adjusted OR [aOR] = 0.98; 95% CI: 0.72, 1.35), whereas incident migraine significantly increased the odds of having an MVC within 1 year (aOR = 3.27; 1.21, 8.82). Prevalent migraine was associated with small reductions in driving days and trips per month and increases in hard braking events in adjusted models.

CONCLUSION

Our results suggest substantially increased likelihood of MVCs in the year after newly diagnosed migraine, indicating a potential need for driving safety interventions in these patients. We found little evidence for MVC risk or substantial changes in driving habits associated with prevalent migraine. Future research should examine timing, frequency, and severity of migraine diagnosis and symptoms, and use of medications specifically prescribed for migraine, in relation to driving outcomes.

Changes in the burden of medications that may impair driving among older adults before and after a motor vehicle crash

BACKGROUND

Medications are one of the most easily modifiable risk factors for motor vehicle crashes (MVCs) among older adults, yet limited information exists on how the use of potentially driver-impairing (PDI) medications changes following an MVC. Therefore, we examined the number and types of PDI medication classes dispensed before and after an MVC.

METHODS

This observational study included Medicare fee-for-service beneficiaries aged ≥67 years who were involved in a police-reported MVC in New Jersey as a driver between 2008 and 2017. Analyses were conducted at the "person-crash" level because participants could be involved in more than one MVC. We examined the use of 36 PDI medication classes in the 120 days before and 120 days after MVC. We described the number and prevalence of PDI medication classes in the pre-MVC and post-MVC periods as well as the most common PDI medication classes started and stopped following the MVC.

RESULTS

Among 124,954 person-crashes, the mean (SD) age was 76.0 (6.5) years, 51.3% were female, and 83.9% were non-Hispanic White. The median (Q1 , Q3 ) number of PDI medication classes was 2 (1, 4) in both the pre-MVC and post-MVC periods. Overall, 20.3% had a net increase, 15.9% had a net decrease, and 63.8% had no net change in the number of PDI medication classes after MVC. Opioids, antihistamines, and thiazide diuretics were the top PDI medication classes stopped following MVC, at incidences of 6.2%, 2.1%, and 1.7%, respectively. The top medication classes started were opioids (8.3%), skeletal muscle relaxants (2.2%), and benzodiazepines (2.1%).

CONCLUSIONS

A majority of crash-involved older adults were exposed to multiple PDI medications before and after MVC. A greater proportion of person-crashes were associated with an increased rather than decreased number of PDI medications. The reasons why clinicians refrain from stopping PDI medications following an MVC remain to be elucidated.

Older Adults and Unintentional Injury

Clinicians play an important role in the prevention of unintentional injuries. Falls and motor vehicle crashes (MVC) have predictable and overlapping antecedents. Systematic screening for and management of vision impairment, frailty, cognitive impairment, polypharmacy, and inappropriate medications will reduce both falls and MVC risks. Fall-prevention measures, such as strength training, need to be more widely prescribed by physicians and implemented by older adults. Technologically tailored approaches are needed to leverage fall-reduction programs at home, as well as education of older adults regarding home hazards.

Medications and traffic accidents involving older drivers: do Spanish primary healthcare physicians know enough?

BACKGROUND

Our aim was to evaluate Spanish family doctors' knowledge about medications that increase the risk of traffic accidents involving older drivers, and to obtain data about the involvement of family doctors in accident prevention activities and the associations between these factors and their demographic and workplace characteristics.

METHODS

A cross-sectional study of 1888 family doctors throughout Spain was carried out from 2016 to 2018. Participants completed a previously validated self-administered questionnaire that explored whether family doctors distinguished between medications associated with a high or low risk of involvement in a traffic accident, investigated the appropriateness of advice given to older patients, and physicians' involvement in preventive activities. Multiple regression models were used to estimate the adjusted association of these variables with each other and with characteristics of family doctors in the sample.

RESULTS

On a scale of 1 (never or hardly ever) to 4 (always), the indexes constructed to evaluate how often family doctors believed they should oversee the use of high-risk and low-risk medications yielded values of 3.38 for the former and 2.61 for the latter (p < 0.001). Only 24% responded correctly to all three items that inquired about the appropriateness of the advice they gave to older patients. On a scale of 1 to 4, the frequency at which family doctors gave older patients advice about preventive measures was 2.85, and only 43% reported allocating time during appointments to provide this advice. These latter two variables were directly associated with appropriate values for the index used to evaluate physicians' oversight of medications associated with a high risk. The perception of risk associated with medications and involvement in preventive activities were both greater among female participants.

CONCLUSIONS

Family doctors correctly identified medications according to their risk of playing a role in traffic accidents, although the recommendations they gave to their patients were not always appropriate. These findings, along with physicians' infrequent involvement in preventive activities, suggest a need to improve family doctors' competencies and increase the resources available to them so that they can provide their older patients with advice on ways to prevent involvement in traffic accidents.

Motor Vehicle Crash Risk in Older Adult Drivers With Attention-Deficit/Hyperactivity Disorder

Importance

Symptoms of attention-deficit/hyperactivity disorder (ADHD), such as inattentiveness and impulsivity, could affect daily functioning and driving performance throughout the life span. Previous research on ADHD and driving safety is largely limited to adolescents and young adults.

Objective

To examine the prevalence of ADHD and the association between ADHD and crash risk among older adult drivers.

Design, Setting, and Participants

This prospective cohort study collected data from primary care clinics and residential communities in 5 US sites (Ann Arbor, Michigan; Baltimore, Maryland; Cooperstown, New York; Denver, Colorado; and San Diego, California) between July 6, 2015, and March 31, 2019. Participants were active drivers aged 65 to 79 years at baseline enrolled in the Longitudinal Research on Aging Drivers project who were studied for up to 44 months through in-vehicle data recording devices and annual assessments. The data analysis was performed between July 15, 2022, and August 14, 2023.

Exposure

Lifetime ADHD based on an affirmative response to the question of whether the participant had ever had ADHD or had ever been told by a physician or other health professional that he or she had ADHD.

Main Outcomes and Measures

The main outcomes were hard-braking events defined as maneuvers with deceleration rates of 0.4g or greater, self-reported traffic ticket events, and self-reported vehicular crashes. Multivariable negative binomial modeling was used to estimate adjusted incidence rate ratios (aIRRs) and 95% CIs of outcomes according to exposure status.

Results

Of the 2832 drivers studied, 1500 (53.0%) were women and 1332 (47.0%) were men with a mean (SD) age of 71 (4) years. The lifetime prevalence of ADHD in the study sample was 2.6%. Older adult drivers with ADHD had significantly higher incidence rates of hard-braking events per 1000 miles than those without ADHD (1.35 [95% CI, 1.30-1.41] vs 1.15 [95% CI, 1.14-1.16]), as well as self-reported traffic ticket events per 1 million miles (22.47 [95% CI, 16.06-31.45] vs 9.74 [95% CI, 8.99-10.55]) and self-reported vehicular crashes per 1 million miles (27.10 [95% CI, 19.95-36.80] vs 13.50 [95% CI, 12.61-14.46]). With adjustment for baseline characteristics, ADHD was associated with a significant 7% increased risk of hard-braking events (aIRR, 1.07; 95% CI, 1.02-1.12), a 102% increased risk of self-reported traffic ticket events (aIRR, 2.02; 95% CI, 1.42-2.88), and a 74% increased risk of self-reported vehicular crashes (aIRR, 1.74; 95% CI, 1.26-2.40).

Conclusions and Relevance

As observed in this prospective cohort study, older adult drivers with ADHD may be at a significantly elevated crash risk compared with their counterparts without ADHD. These findings suggest that effective interventions to improve the diagnosis and clinical management of ADHD among older adults are warranted to promote safe mobility and healthy aging.

Special Report from the CDC: Provider knowledge and practices around driving safety and fall prevention screening and recommendations for their older adult patients, DocStyles 2019

INTRODUCTION

Falls and motor-vehicle crashes (MVCs) are leading causes of unintentional injury deaths among older adults (65+) in the United States. Injury prevention resources exist to help healthcare providers reduce fall and MVC risk among older adult patients. However, awareness of these resources among healthcare providers is unclear.

METHODS

Questions were included in the 2019 DocStyles survey that assessed healthcare provider awareness of three injury prevention resources: (1) the American Geriatrics Society's (AGS's) Clinician's Guide to Assessing and Counseling Older Drivers, (2) the Clinical Assessment of Driving Related Skills (CADReS), and (3) the Centers for Disease Control and Prevention's (CDC) Stopping Elderly Accidents, Deaths, and Injuries (STEADI) initiative. We also explored the circumstances and current practices for counseling older adult patients on fall prevention and driving safety.

RESULTS

Only 20% of providers reported awareness of any of the injury prevention resources. Providers were more likely to report either screening for fall risk or unsafe driving when an older adult presented with a fall concern (74.5%) or driving concern or recent crash (85.1%), compared to annual screening for fall risk (67.7%) or driving safety (47.7%). More providers reported discussing the increased fall or MVC risk associated with patient medications, referring patient for driving fitness evaluations, or discussing alternative transportation options with the patient after adverse events or patient-initiated concerns compared to routine annual discussions.

CONCLUSION

Healthcare gaps persist in the screening and assessment of older adult risk factors for falls and unsafe driving. Limited provider awareness of clinical resources related to preventing older adult falls and unsafe driving may be contributing to these healthcare gaps.

PRACTICAL APPLICATIONS

Improving healthcare provider awareness of these resources could help them identify older adults at risk of a fall or MVC and promote injury prevention efforts in their clinical practices.

A probabilistic bias analysis on the magnitude of unmeasured confounding: The impact of driving mileage on road traffic crashes

INTRODUCTION

Unmeasured confounding can lead to biased interpretations of empirical findings. This paper aimed to assess the magnitude of suspected unmeasured confounding due to driving mileage and simulate the statistical power required to detect a discrepancy in the effect of polypharmacy on road traffic crashes (RTCs) among older adults.

METHODS

Based on Monte Carlo Simulation (MCS) approach, we estimated 1) the magnitude of confounding of driving mileage on the association of polypharmacy and RTCs and 2) the statistical power of to detect a discrepancy from no adjusted effect. A total of 1000 studies, each of 500000 observations, were simulated.

RESULTS

Under the assumption of a modest adjusted exposure-outcome odds ratio of 1.35, the magnitude of confounding bias by driving mileage was estimated to be 16% higher with a statistical power of 50%. Only an adjusted odds ratio of at least 1.60 would be associated with a statistical power of about 80% CONCLUSION: This applied probabilistic bias analysis showed that not adjusting for driving mileage as a confounder can lead to an overestimation of the effect of polypharmacy on RTCs in older adults. Even considering a large sample, small to moderate adjusted exposure effects were difficult to be detected.

Driving under the influence of substances and motor vehicle fatalities among older adults in the United States

OBJECTIVE

This study examines contribution of substance use (including alcohol, cannabinoids, stimulants, narcotics, depressants, and hallucinogens) on the probability of drivers being at-fault for a crash on U.S. public roads, with specific emphasis on older adult drivers.

METHODS

Data from the National Highway Traffic Safety Administration's Fatality Analysis Reporting System (FARS) for the years 2010-2018 were employed for 87,060 drivers (43,530 two-vehicle crash pairs) involved in two moving vehicle crashes. The quasi-induced exposure (QIE) method was used to compute the relative crash involvement ratios (CIRs) for each relevant substance and illicit drug. Mixed-effect generalized linear regression models were fit to examine the effect of substance use on the probability of a driver being at-fault for a crash.

RESULTS

There were 75.51% males and 73.88% Non-Hispanic Whites in our sample. The CIR for those aged 70-79 years was 1.17, and more than double (2.56) for the ≥80 years old drivers, while being relatively low among drivers of ages 20 to 69. Substance use, in general, disproportionately increased the probability of being at-fault during a crash, regardless of driver's age. Though older drivers are less likely than other age groups to report substance use, presence of substances among older drivers increased the probability of their being at-fault two to four times during a crash across almost all substances. The regression models, after adjusting for driver's sex, road grade, weather, light conditions, distraction, and speeding at time of crash, revealed that older drug-impaired drivers were twice as likely to be at fault in a fatal crash (aOR = 1.947; 95% CI = 1.821, 2.082; <0.0001) compared to their middle-aged counterparts. Similarly, most substance use categories were responsible for the probabilities of higher CIRs among the drivers.

CONCLUSION

These findings necessitate continued efforts to bring awareness to the deadly consequences of "drugged driving," especially among older adult drivers.

Driving communication forward: improving communication for palliative care patients around driving and opioids - a quality improvement report

INTRODUCTION

The number of people requiring palliative care is increasing with an ageing comorbid population. Pain is a prevalent symptom for palliative care patients and is often managed with opioids. Opioids reduce reaction time and can cause drowsiness and visual disturbance. Evidence recommends that driving should be avoided until a stable dose of opioids has been reached. It is vital for patient and public safety that these facts are communicated to patients who are prescribed opioids, as well as the legal consequences if guidance is not followed. These discussions facilitate joint decisions, optimising patient freedom and quality of life. Surprisingly though these important discussions around driving and opioids do not always occur, and so this project sought to develop a systematic approach to integrating them into practice.

DESIGN

Retrospective case note analysis and prospective interventional quality improvement study.

SETTING

A 16 bedded specialist palliative care inpatient unit.

POPULATION

Hospice inpatients with an Eastern Council Oncology Group performance score of 0-3 who had been prescribed opioids.

INTERVENTION

Three plan-do-study-act cycles were performed. First, the issue was discussed in the daily multidisciplinary team meeting to raise awareness, second a prompt was added to a pre-existing clerking proforma. Finally, a reminder poster was placed in the ward office to promote discussion prior to discharge.

OUTCOME MEASURES

Primary measures were the proportion of patients with the presence of documented driving status, and the presence of a documented discussion surrounding driving and opioids.

RESULTS

Baseline data found that 11.5% of patients had a documented driving status and 11.5% had a documented discussion surrounding driving and opioids. Over the course of the study, the proportion improved to 65.2% and 60.9%, respectively.

CONCLUSION

Use of quality improvement change methods have resulted in the successful integration of new interventions to increase discussions around driving when prescribed opioids. A previously overlooked issue in this facility, thus improving clinical and patient information sharing, and patient empowerment to take charge of their own health.

[Diabetes mellitus and road traffic-a position paper of the Austrian Diabetes Association (update 2023)]

Public safety (prevention of accidents) is the primary objective in assessing fitness to drive a motor vehicle. However, general access to mobility should not be restricted if there is no particular risk to public safety. For people with diabetes mellitus, the Führerscheingesetz (Driving Licence Legislation) and the Führerscheingesetz-Gesundheitsverordnung (Driving Licence Legislation Health enactment) regulate important aspects of driving safety in connection with acute and chronic complications of the disease. Critical complications that may be relevant to road safety include severe hypoglycemia, pronounced hyperglycemia and hypoglycemia perception disorder as well as severe retinopathy and neuropathy, endstage renal disease and certain cardiovascular manifestations. If there is a suspicion of the presence of one of these complications, a detailed evaluation is required.In addition, the individual antihyperglycemic medication should be checked for existing potential for hypoglycemia. Sulfonylureas, glinides and insulin belong to this group and are therefore associated with the requirement of a 5-year limitation of the driver's license. Other antihyperglycemic drugs without potential for hypoglycemia such as Metformin, SGLT‑2 inhibitors (Sodium-dependent-glucose-transporter‑2 inhibitors, gliflozins), DPP-4-inhibitors (Dipeptidyl-Peptidase inhibitors, gliptins), and GLP‑1 analogues (GLP‑1 rezeptor agonists) are not associated with such a time limitation.The relevant laws which regulate driving safety give room for interpretation, so that specific topics on driving safety for people with diabetes mellitus are elaborated from a medical and traffic-relevant point of view. This position paper is intended to support people involved in this challenging matter.

Association of falls and fear of falling with objectively-measured driving habits among older drivers: LongROAD study

OBJECTIVE

Falls in older adults are associated with increased motor vehicle crash risk, possibly mediated by driving behavior. We examined the relationship of falls and fear of falling (FOF) with subsequent objectively measured driving habits.

METHODS

This multi-site, prospective cohort study enrolled 2990 active drivers aged 65-79 (53% female). At enrollment, we assessed falls in the past year and FOF (Short Falls Efficacy Scale-International). Driving outcomes included exposure, avoidance of difficult conditions, and unsafe driving during one-year follow-up, using in-vehicle Global Positioning System devices.

RESULTS

Past-year falls were associated with more hard braking events (HBE). High FOF was associated with driving fewer days, miles, and trips, driving nearer home and more HBE. Differences were attenuated and not significant after accounting for health, function, medications and sociodemographics.

DISCUSSION

Differences in objectively measured driving habits according to past-year fall history and FOF were largely accounted for by differences in health and medications. Rather than directly affecting driving, falls and FOF may serve as markers for crash risk and reduced community mobility due to age-related changes and poor health.

Use of potentially driver-impairing drugs among older drivers

BACKGROUND

Road safety is a major issue among seniors. Potentially Driver-Impairing (PDI) drugs are known to increase the risk of car accident. The aim of this cross-sectional study was to describe PDI-drug consumption among older drivers and determine associated factors.

METHODS

The S.AGES cohort is a French non-interventional real-life prospective study of 3700 community-dwelling participants aged ≥65 years old, suffering from type 2 diabetes (T2DM), chronic pain or atrial fibrillation (AF). Baseline data of drivers with known treatment (n = 1783) were used for the analyses. PDI drugs were defined according to the French classification.

RESULTS

One thousand seven hundred eighty-three drivers were included (66% males; mean age 76 (Standard deviation = 5.78) years old). 21% (n = 373) took PDI drugs, 64% of which took only one (n = 239). The most frequent PDI drugs were: Zolpidem (11%; n = 60); Zopiclone (8%; n = 45); Bromazepam (8%; n = 44); Tramadol (7%; n = 39); Pregabalin (6%; n = 31). Drivers taking PDI drugs had more often chronic pain (OR [95% CI] = 2.30 [1.54-3.46]), history of depressive disorder (4.28 [3.00-6.14]) and polypharmacy (taking at least 5 different medications; 4.32 [2.97-6.41]), and less often T2DM (0.54 [0.37-0.79]), and AF (0.48 [0.32-0.71]). Conversely, they had a lower Activities of Daily Living score (0.34 [0.17-0.68]).

CONCLUSIONS

The rate of aged drivers in the S.AGES cohort taking PDI drugs is concerning and highlights the need to carefully assess and reassess PDI-drug prescriptions in this population, particularly hypnotics, anxiolytics and opioids.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01065909 (First posted: February 9th, 2010).

The Impact of Cognition and Gender on Speeding Behaviour in Older Drivers with and without Suspected Mild Cognitive Impairment

Purpose

Mild cognitive impairment and gender can impact different aspects of driving performance and behaviour in older drivers. However, there is little evidence on how these may affect naturalistic speeding behaviour. Therefore, the aim of this study was to examine the relationship between speeding events and cognitive status for older male and female drivers.

Participants and Methods

A naturalistic driving study collected objective driving information over a two-week period using an in-vehicle monitoring device from 36 older drivers with suspected mild cognitive impairment and 35 older drivers without cognitive impairment. The outcome of interest examined was the number of speeding events, defined as travelling 5+ km/h over the posted speed limit for at least a minute.

Results

The majority of participants (n=58, 81.69%) did not have a speeding event during the two-week monitoring period. Twenty-three speeding events were recorded among seven drivers with suspected mild cognitive impairment and six drivers without cognitive impairment. The majority of speeding events (82.61%) were by older male drivers and occurred in 60km/h and 70km/h speed zones. The results of the two negative binomial regression models found that in older male drivers, suspected mild cognitive impairment (IRR=7.45, 95% CI=1.53–36.15, p=0.01) was associated with a significantly higher rate of speeding events, while increasing age was associated with a lower rate of speeding events (IRR=0.80, 95% CI=0.64–1.00, p=0.04). For older female drivers, there were no factors significantly associated with the rate of speeding events.

Conclusion

While the overall number of speeding events were infrequent, suspected mild cognitive impairment was associated with a significant increase in the rate of speeding events for older male drivers, but not for older female drivers. Speeding interventions and injury prevention policy strategies may need to be targeted differently for male and female drivers with mild cognitive impairment.

Potentially Inappropriate Medication Use and Hard Braking Events in Older Drivers

Potentially inappropriate medications (PIMs) identified by the American Geriatrics Society should generally be avoided by older adults because of ineffectiveness or excess risk of adverse effects. Few studies have examined the effects of PIMs on driving safety measured by prospectively and objectively collected driving data. Data for this study came from the Longitudinal Research on Aging Drivers study, a multisite naturalistic driving study of older adults. Multivariable negative binominal modeling was used to estimate incidence rate ratios and 95% confidence intervals of hard braking events (proxies for unsafe driving behavior defined as events with a deceleration rate ≥0.4 g) associated with PIM use among older drivers. The study sample consisted of 2932 drivers aged 65-79 years at baseline, including 542 (18.5%) who used at least one PIM. These drivers were followed through an in-vehicle recording device for up to 44 months. The overall incidence of hard braking events was 1.16 per 1000 miles. Use of PIMs was associated with a 10% increased risk of hard braking events. Compared to drivers who were not using PIMs, the risk of hard braking events increased 6% for those using one PIM, and 24% for those using two or more PIMs. Use of PIMs by older adult drivers is associated in a dose-response fashion with elevated risks of hard braking events. Reducing PIM use in older adults might help improve driving safety as well as health outcomes.

Age-Related Diseases and Driving Safety

Due to demographic changes, the number of older drivers is steadily increasing. Mobility is highly relevant for leading an independent life in the elderly. It largely depends on car driving, which is a complex task requiring a multitude of cognitive and motor skills vulnerable to age- related functional deterioration. The almost inevitable effects of senescence may be potentiated by age-related diseases, such as stroke or diabetes mellitus. Respective pharmacological treatment may cause side effects, additionally affecting driving safety. The present article reviews the impact of age-related diseases and drug treatment of these conditions on driving fitness in elderly drivers. In essence, we focus on diseases of the visual and auditory systems, diseases of the central nervous system (i.e., stroke, depression, dementia and mild cognitive disorder, and Parkinson's disease), sleep disorders, as well as cardiovascular diseases, diabetes mellitus, musculoskeletal disorders, and frailty. We will outline the role of functional tests and the assessment of driving behavior (by a driving simulator or in real traffic), as well as the clinical interview including questions about frequency of (near) accidents, etc. in the evaluation of driving fitness of the elderly. We also address the impact of polypharmacy on driving fitness and end up with recommendations for physicians caring for older patients.