Medical conditions and the risk of motor vehicle crashes in men

Acute medical impairment among elderly patients involved in motor vehicle collisions

BACKGROUND

The association between acute medical illness and motor vehicle collisions (MVCs) among elderly emergency department patients is unclear. We sought to determine the prevalence of acute medical conditions that might impair driving ability among the elderly involved in MVCs and determine if there was an increased risk of the driver having an acute medical condition compared to similarly aged passengers.

METHODS

We reviewed charts of patients aged 65 years or older whose emergency department visit was prompted by a motor vehicle collision between 1 July 2000 and 30 June 2010 at two Level 1 trauma centres. The exposure of interest was occupancy status (driver vs. passenger), and the outcome measure was the presence of any predefined acute medical illness that might impair driving ability.

RESULTS

Final analysis included 871 drivers (cases) and 307 passengers (controls). An acute medical illness was recorded in 107 patients (9%): 97 drivers (11%) and 10 passengers (3%). Compared to passengers, drivers had significantly higher odds of presenting with acute medical illness (OR 3.7, 95% CI 1.9-7.2). After controlling for potential confounders, the adjusted odds ratio was 5.5 (95% CI 2.3-13.0).

CONCLUSION

Acute medical conditions are a moderately common diagnosis among elderly drivers, presenting in about one in ten patients. A difference in the risk of finding an acute medical illness when comparing elderly drivers and passengers evaluated in the emergency department after a collision suggests the need for considering additional diagnostic investigation and post-discharge surveillance in this population.

Increased risk of hospitalization related to motor vehicle accidents among people taking zolpidem: a case-crossover study

BACKGROUND

Several epidemiological and experimental studies have found a positive association between the risk of motor vehicle accidents (MVAs) and use of zopiclone and benzodiazepines. There is, however, little evidence of any risk of MVA attributable to the use of zolpidem 1 day before such accidents. We attempted to determine whether the use of zolpidem 1 day before is associated with an increased risk of an MVA.

METHODS

Using a 1-million-person randomly sampled cohort from the Taiwan National Health Insurance reimbursement database, 12 929 subjects were identified as having been hospitalized between 1998 and 2004 due to an MVA. Using a case-crossover design, we selected the day before an MVA as the case period for each subject, and the 91st, 182nd, and 273rd days before the case period as 3 retrospective control periods. Conditional logistical regression models were constructed to calculate the odds ratio (OR) of having an MVA and the exposure of zolpidem 1 day before. We calculated doses of benzodiazepines, zopiclone, and zolpidem based on their defined daily dose.

RESULTS

The adjusted OR for involvement in an MVA after taking 1 defined daily dose of zolpidem was 1.74 (95% confidence interval: 1.25-2.43). There were also positive effects for different washout periods and cumulative doses at 7, 14, 21, and 28 days before the occurrence of an MVA.

CONCLUSIONS

Use of zolpidem 1 day before might be associated with an increased risk of MVA. Thus, precautionary warnings should be provided when prescribing zolpidem.

Diseases, consumption of medicines and responsibility for a road crash: a case-control study

The role of medical conditions in crashes is a topic of public debate. Some studies suggest that there has been a reduction in road traffic crashes subsequent to the medical restrictions introduced on drivers with medical deficiencies. As in today's society the car is an important factor for independence and socialization, it seems important to consider whether diseases or consumption of drugs increase the risk of causing a road crash in comparison to well-known major crash risk factors. A case-control study was conducted (733 injured drivers). The cases were subjects who were partly or totally responsible for their crash. The 304 controls were the non-responsible drivers. Diseases and medicine consumption were analyzed using logistic regression models. Cases were characterized by a higher percentage of young men. They were more frequently affected by fatigue, as were subjects who had consumed alcohol. A higher risk in subjects suffering from hypertension is observed (adjusted odds ratio [adjOR]=3.82; 95%CI=[1.42-10.24]). An association between antidepressant consumption and responsibility appeared (adjOR=3.61; 95%CI=[1.30-10.03]).

CONCLUSION

Medical factors associated with responsibility were arterial hypertension and antidepressant consumption. Other medical conditions do not seem to play a preponderant role comparing to individual behaviours.

Can High-Risk Older Drivers Be Identified Through Performance-Based Measures in a Department of Motor Vehicles Setting?

OBJECTIVES

To evaluate the relationship between performance-based risk factors and subsequent at-fault motor vehicle collision (MVC) involvement in a cohort of older drivers.

DESIGN

Prospective cohort study.

SETTING

Motor Vehicle Administration (MVA) field sites in Maryland.

PARTICIPANTS

Of the 4,173 older drivers invited to participate in the study, 2,114 individuals aged 55 to 96 agreed to do so. These analyses focus on 1,910 individuals recruited through MVA field sites.

MEASUREMENTS

Gross Impairment Screening Battery, which included Rapid Pace Walk, Head/Neck Rotation, Foot Tap, Arm Reach, Cued Recall, Symbol Scan, Visual Closure subtest of the Motor Free Visual Perception Test (MVPT), Delayed Recall, and Trail Making Test with an Abbreviated Part A and standard Part B; Useful Field of View (UFOV) subtest 2; a Mobility Questionnaire; and MVC occurrence.

RESULTS

In drivers aged 55 and older with intact vision (20/70 far visual acuity and 140 degrees visual field), age, sex, history of falls, and poorer cognitive performance, as measured using Trails B, MVPT, and UFOV subtest 2, were predictive of future at-fault MVC involvement. After adjusting for annual mileage, participants aged 78 and older were 2.11 as more likely to be involved in an at-fault MVC, those who made four or more errors on the MVPT were 2.10 times as likely to crash, those who took 147 seconds or longer to complete Trails B were 2.01 times as likely to crash, and those who took 353 ms or longer on subtest 2 of the UFOV were 2.02 times as likely to incur an at-fault MVC. Older adults, men, and individuals with a history of falls were more likely to be involved in subsequent at-fault MVCs.

CONCLUSION

Performance-based cognitive measures are predictive of future at-fault MVCs in older adults. Cognitive performance, in particular, is a salient predictor of subsequent crash involvement in older adults. High-risk older drivers can be identified through brief, performance-based measures administered in a MVA setting.

Risk factors for motor vehicle crashes in older women

BACKGROUND

Motor vehicle crash and fatality rates are higher per mile driven for elderly drivers, with an exponential increase above age 75. Identifying elderly drivers who are at risk for automobile crashes may help direct interventions to reduce their high rate of injuries and deaths.

METHODS

Subjects were 1416 women aged 65 to 84 enrolled in the Portland, Ore. site of the Study of Osteoporotic Fractures. Motor vehicle crash information for the years 1986-1995 for each participant was obtained from the Oregon State Department of Transportation. Items from questionnaires, interviews, and physical examinations were tested prospectively for associations with the occurrence of motor vehicle crashes.

RESULTS

About one third of participants (415 of 1416) had a motor vehicle crash during a mean follow-up time of 5.7 years. After adjustment for age and weekly driving mileage, risk factors significantly associated with motor vehicle crashes were a fall in the previous year [hazard ratio (HR) 1.53, 95% confidence interval (CI) 1.26-1.86], a greater orthostatic systolic blood pressure drop (HR 1.11 per 12.5 mm Hg, 95% CI 1.01-1.22), and increased foot reaction time (HR 1.10 per 0.06 second, 95% CI 1.00-1.22). Other neuromuscular tests, functional status, medical diagnoses, vision tests, and cognitive tests did not predict motor vehicle crashes in this study population.

CONCLUSIONS

This prospective study with extended follow-up of a large cohort of elderly women has identified crash risk factors that can be measured in the clinical setting. Further study is needed to determine if interventions aimed at these risk factors can decrease the risk of motor vehicle crashes.