The distribution of sleepiness,sleep and work hours during a long distance morning trip: A comparison between night- and non-night workers

Few studies have examined the extent of driver sleepiness during a long distance morning trip. Sleepiness at this time may be high because of night work, waking early to commence work or travel, sleep disorders and the monotony of driving long distances. The objective of this study was to estimate the prevalence of chronic sleepiness (Epworth sleepiness score ≥ 10) and sleep restriction (≤5 h) in a sample of 649 drivers. Participants driving between 08:00 and 10:00 on three highways in regional Australia participated in a telephone interview. Approximately 18% of drivers reported chronic sleepiness. The proportions of night workers (NW) and non-night workers (NNW) with chronic sleepiness were not significantly different but males reported a significantly greater proportion of chronic sleepiness than females. The NW group had a significantly greater proportion of drivers with ≤5 h of sleep in the previous 24 and 48 h, fewer nights of full sleep (≤4), acute sleepiness and longer weekly work hours. The NW group reported driving a significantly longer distance at Time 1 (Mean = 140.29 ± 72.17 km, versus 117.55 ± 89.74 km) and an additional longer distance to complete the journey (Mean = 89.33 ± 95.23 km, versus 64.77 ± 94.07 km). The high proportions of sleep restriction and acute sleepiness among the NW group, and the amount of chronic sleepiness in the NW and NNW groups reported during a long distance morning trip may be of concern for driver safety.     

Cognitive components of simulated driving performance: Sleep loss effects and predictors

Driving is a complex task, which can be broken down into specific cognitive processes. In order to determine which components contribute to drowsy driving impairments, the current study examined simulated driving and neurocognitive performance after one night of sleep deprivation. Nineteen professional drivers (age 45.3 ± 9.1) underwent two experimental sessions in randomised order: one after normal sleep and one after 27 h total sleep deprivation. A simulated driving task (AusEd), the psychomotor vigilance test (PVT), and neurocognitive tasks selected from the Cognitive Drug Research computerised neurocognitive assessment battery (simple and choice RT, Stroop Task, Digit Symbol Substitution Task, and Digit Vigilance Task) were administered at 10:00 h in both sessions. Mixed-effects ANOVAs were performed to examine the effect of sleep deprivation versus normal sleep on performance measures. To determine if any neurocognitive tests predicted driving performance (lane position variability, speed variability, braking RT), neurocognitive measures that were significantly affected by sleep deprivation were then added as a covariate to the ANOVAs for driving performance. Simulated driving performance and neurocognitive measures of vigilance and reaction time were impaired after sleep deprivation (p < 0.05), whereas tasks examining processing speed and executive functioning were not significantly affected by sleep loss. PVT performance significantly predicted specific aspects of simulated driving performance. Thus, psychomotor vigilance impairment may be a key cognitive component of driving impairment when sleep deprived. The generalisability of this finding to real-world driving remains to be investigated.     

Exploring the effects of lifestyle, sleep factors and driving behaviors on sleep-related road risk: A study of Greek drivers

Purpose

The present study explored the effect of various lifestyle patterns and sleep-related factors on the sleep-related road risk. Sleep-related factors included daytime sleepiness, drowsy driving and quality/quantify of sleep.

Methods

A sample of 1366 non-professional drivers aged 19–65 was selected from the broader Athens area of Greece, using stratified random sampling. The questionnaire solicited information on the participants’ socio-demographic characteristics, driving background, lifestyle patterns, sleep quality and quantity, daytime sleepiness, drowsy driving behavior and sleep-related road risk.

Results

Sleep-related road risk was affected by gender, quantity of night sleep and drowsy driving behavior. Drowsy driving behavior was shown to be related to gender, daytime sleepiness, sleep quality and the lifestyle of “amusement”. Daytime sleepiness was correlated with sleep quality and the lifestyles of “amusement” and “sport”. Finally, sleep quality and quantity were significantly affected by the lifestyles of “amusement” and “yuppies-workaholic”.

Conclusion

The current study has identified a number of risk factors in sleep-related crash risk in the general population of drivers. By raising public awareness the health and safety community can play an important role in reducing, if not preventing, the consequences of this public health problem.     

Specific sleepiness symptoms are indicators of performance impairment during sleep deprivation

Drivers are not always aware that they are becoming impaired as a result of sleepiness. Using specific symptoms of sleepiness might assist with recognition of drowsiness related impairment and help drivers judge whether they are safe to drive a vehicle, however this has not been evaluated. In this study, 20 healthy volunteer professional drivers completed two randomized sessions in the laboratory – one under 24 h of acute sleep deprivation, and one with alcohol. The Psychomotor Vigilance Task (PVT) and a 30 min simulated driving task (AusEdTM) were performed every 3–4 h in the sleep deprivation session, and at a BAC of 0.00% and 0.05% in the alcohol session, while electroencephalography (EEG) and eye movements were recorded. After each test session, drivers completed the Karolinska Sleepiness Scale (KSS) and the Sleepiness Symptoms Questionnaire (SSQ), which includes eight specific sleepiness and driving performance symptoms. A second baseline session was completed on a separate day by the professional drivers and in an additional 20 non-professional drivers for test–retest reliability. There was moderate test–retest agreement on the SSQ (r = 0.59). Significant correlations were identified between individual sleepiness symptoms and the KSS score (r values 0.50–0.74, p < 0.01 for all symptoms). The frequency of all SSQ items increased during sleep deprivation (χ² values of 28.4–80.2, p < 0.01 for all symptoms) and symptoms were related to increased subjective sleepiness and performance deterioration. The symptoms “struggling to keep your eyes open”, “difficulty maintaining correct speed”, “reactions were slow” and “head dropping down” were most closely related to increased alpha and theta activity on EEG (r values 0.49–0.59, p < 0.001) and “nodding off to sleep” and “struggling to keep your eyes open” were related to slow eye movements (r values 0.67 and 0.64, p < 0.001). Symptoms related to visual disturbance and impaired driving performance were most accurate at detecting severely impaired driving performance (AUC on ROC curve of 0.86–0.91 for detecting change in lateral lane position greater than the change at a BAC of 0.05%). Individual sleepiness symptoms are related to impairment during acute sleep deprivation and might be able to assist drivers in recognizing their own sleepiness and ability to drive safely.     

Ocular parameters as an objective tool for the assessment of truck drivers fatigue

Ocular parameters are influenced by sleep derivation and the use of chemical substances which are two major causes for traffic accidents. We assessed the use of these parameters as an objective screening tool for a driver's fitness for duty. Pupillary diameter, pupil reaction to light and saccadic velocity were measured in 29 army truck drivers every morning for two months and compared to baseline measurements taken while the subjects were alert. An index which expressed the difference between study and baseline measurements was calculated, and drivers with significant deviation from baseline were disqualified and interviewed. Non-disqualified drivers served as controls. Twenty-nine percent of disqualified drivers reported sleeping less than the minimum of 7 h required by army regulations compared with 8% of control drivers (p = 0.01). Disqualified drivers had worse sleep quality the night before the test (Groningen Sleep Quality Scale, p = 0.03) and incurred more accidents per driving day during their service (0.023 vs. 0.015 accidents/day, p = 0.03). Two disqualified drivers admitted to using alcohol or sleeping pills. Thus, these ocular parameters may serve as a screening tool for drivers that are at high risk for driving. Drivers who were disqualified even once, tend to be involved in more motor vehicle accidents than their peers.     

The influence of daily sleep patterns of commercial truck drivers on driving performance

Fatigued and drowsy driving has been found to be a major cause of truck crashes. Lack of sleep is the number one cause of fatigue and drowsiness. However, there are limited data on the sleep patterns (sleep duration, sleep percentage in the duration of non-work period, and the time when sleep occurred) of truck drivers in non-work periods and the impact on driving performance. This paper examined sleep patterns of 96 commercial truck drivers during non-work periods and evaluated the influence these sleep patterns had on truck driving performance. Data were from the Naturalistic Truck Driving Study. Each driver participated in the study for approximately four weeks. A shift was defined as a non-work period followed by a work period. A total of 1397 shifts were identified. Four distinct sleep patterns were identified based on sleep duration, sleep start/end point in a non-work period, and the percentage of sleep with reference to the duration of non-work period. Driving performance was measured by safety-critical events, which included crashes, near-crashes, crash-relevant conflicts, and unintentional lane deviations. Negative binomial regression was used to evaluate the association between the sleep patterns and driving performance, adjusted for driver demographic information. The results showed that the sleep pattern with the highest safety-critical event rate was associated with shorter sleep, sleep in the early stage of a non-work period, and less sleep between 1 a.m. and 5 a.m. This study also found that male drivers, with fewer years of commercial vehicle driving experience and higher body mass index, were associated with deteriorated driving performance and increased driving risk. The results of this study could inform hours-of-service policy-making and benefit safety management in the trucking industry.     

Impaired vigilance and increased accident rate in public transport operators is associated with sleep disorders

Objectives

Sleep disturbances can impair alertness and neurocognitive performance and increase the risk of falling asleep at the wheel. We investigated the prevalence of sleep disorders among public transport operators (PTOs) and assessed the interventional effects on hypersomnolence and neurocognitive function in those diagnosed with obstructive sleep apnea (OSA).

Methods

Overnight polygraphy and questionnaire data from 101 volunteers (72 males, median age 48 range [22–64] years, 87 PTOs) employed at the Gothenburg Public Transportation Company were assessed. Treatment was offered in cases with newly detected OSA. Daytime sleep episodes and neurocognitive function were assessed before and after intervention.

Results

At baseline, symptoms of daytime hypersomnolence, insomnia, restless legs syndrome as well as objectively assessed OSA (apnea hypopnea index (AHI, determined by polygraphic recording) = 17[5–46] n/h) were highly present in 26, 24, 10 and 22%, respectively. A history of work related traffic accident was more prevalent in patients with OSA (59%) compared to those without (37%, p < 0.08). In the intervention group (n = 12) OSA treatment reduced AHI by −23 [−81 to −5] n/h (p = 0.002), determined by polysomnography. Reduction of OSA was associated with a significant reduction of subjective sleepiness and blood pressure. Measures of daytime sleep propensity (microsleep episodes from 9 [0–20.5] to 0 [0–12.5], p < 0.01) and missed responses during performance tests were greatly reduced, indices of sustained attention improved.

Conclusions

PTOs had a high prevalence of sleep disorders, particularly OSA, which demonstrated a higher prevalence of work related accidents. Elimination of OSA led to significant subjective and objective improvements in daytime function. Our findings argue for greater awareness of sleep disorders and associated impacts on daytime function in public transport drivers.     

Young novice drivers and the risky behaviours of parents and friends during the Provisional (intermediate) licence phase: A brief report

Purpose

While there is research indicating that many factors influence the young novice driver's increased risk of road crash injury during the earliest stages of their independent driving, there is a need to further understand the relationship between the perceived risky driving behaviour of parents and friends and the risky behaviour of drivers with a Provisional (intermediate) licence.

Method

As part of a larger research project, 378 drivers aged 17–25 years (M = 18.22, SD = 1.59, 113 males) with a Provisional licence completed an online survey exploring the perceived riskiness of their parents’ and friends’ driving, and the extent to which they pattern (i.e. base) their driving behaviour on the driving of their parents and friends.

Results

Young drivers who reported patterning their driving on their friends, and who reported they perceived their friends to be risky drivers, reported more risky driving. The risky driving behaviour of young male drivers was associated with the perceived riskiness of their fathers’ driving, whilst for female drivers the perceived riskiness of their mothers’ driving approached significance.

Conclusions

The development and application of countermeasures targeting the risky behaviour of same-sex parents appears warranted by the robust research findings. In addition, countermeasures need to encourage young people in general to be non-risky drivers; targeting the negative influence of risky peer groups specifically. Social norms interventions may minimise the influence of potentially-overestimated riskiness.     

Early morning awakening and nonrestorative sleep are associated with increased minor non-fatal accidents during work and leisure time

Background

The relationship between a composite measure of insomnia and occupational or fatal accidents has been investigated previously; however, little is known regarding the effect of various insomnia symptoms on minor non-fatal accidents during work and leisure time.

Objective

We investigated the predicting role of insomnia symptoms on minor non-fatal accidents during work and leisure time.

Methods

Data from the 2005 Taiwan Social Development Trend Survey of 36,473 Taiwanese aged ≥18 years were analyzed in 2013. Insomnia symptoms, including difficulty in initiating sleep (DIS), difficulty in maintaining sleep (DMS), early morning awakening (EMA), and nonrestorative sleep (NRS) were investigated. A minor non-fatal accident was defined as any mishap such as forgetting to turn off the gas or faucets, accidental falls, and abrasions or cuts occurring during work and leisure time in the past month that do not require immediate medical attention. Multivariable logistic regression was performed to assess the odds ratios (ORs) and associated 95% confidence interval (CI) of minor non-fatal accidents (as a binary variable) for each insomnia symptom compared with those of people presenting no symptoms, while controlling for possible confounders.

Results

EMA and NRS increased the odds of minor non-fatal accidents occurring during work and leisure time (adjusted OR = 1.19, 95% CI = 1.08–1.32 and adjusted OR = 1.27, 95% CI = 1.17–1.37, respectively).

Conclusion

EMA and NRS are two symptoms that are significantly associated with an increased likelihood of minor non-fatal accidents during work and leisure time after adjusting for of a range of covariates.     

Reliability of simulator driving tool for evaluation of sleepiness,fatigue and driving performance

Study objective

To compare the impact of extended wakefulness (i.e., sleepiness) and prolonged driving (i.e., fatigue) at the wheel in simulated versus real-life driving conditions.

Design

Participants drove on an INRETS-MSIS SIM2 simulator in a research laboratory or an open French highway during 3 nocturnal driving sessions. A dose–response design of duration of nocturnal driving was used: a 2 h short driving session (3–5 AM), a 4 h intermediate driving session (1–5 AM) and an 8 h long driving session (9 PM–5 AM).

Participants

Two groups of healthy male drivers (20 for simulated driving and 14 drivers for real driving; mean age ± SD = 22.3 ± 1.6 years), free of sleep disorders.

Measurements

Number of inappropriate line crossings, self-rated fatigue and sleepiness were recorded in the last hour of driving sessions to control the effects of prior waking time and time of day.

Results

Compared to the daytime reference session, both simulated and real driving performance were affected by a short nocturnal driving session (P < .05 and P < .001, respectively). Extension of nocturnal driving duration affected simulated performance nonlinearly and more severely than that of real driving (P < .001).Compared to the daytime reference session, short nocturnal simulated and real driving sessions increased self-perceived fatigue and sleepiness. Real and simulated driving conditions had an identical impact on fatigue and sleepiness during extended periods of nocturnal driving.

Conclusions

In healthy subjects, the INRETS-MSIS SIM2 simulator appropriately measures driving impairment in terms of inappropriate line crossings related to extended wakefulness but has limitations to measure the impact of extended driving on drivers’ performance.     

Associations among nocturnal sleep,daytime intradialytic sleep,and mortality risk in patients on daytime conventional hemodialysis: US Renal Data System special study data

Fragmented nocturnal sleep is commonly reported by patients undergoing daytime conventional hemodialysis (CHD) and may be associated with higher mortality risk. Subjective sleepiness during CHD is also frequently observed. We examined the association of reported sleep fragmentation and nocturnal and daytime (intradialytic) sleep durations with survival in a national cohort of 1440 CHD patients who were interviewed in 2005–2007 in a phone survey conducted by the US Renal Data System. Patient survival was followed through September 30, 2010 in the US Renal Data System. A total of 76% of patients reported that they typically dozed off or slept during their treatment, and intradialytic dozing was especially common among patients whose treatment shift started before 1000 hours. There was a trend for patients who reported dozing during CHD to report nocturnal sleep fragmentation (60.4% vs. 55.1%; P = 0.07). With adjustment for intradialytic sleep and other covariates, nocturnal sleep fragmentation was not associated with survival. Mortality risk was higher for patients who reported sleeping 9 or more hours/night compared with the referent category of nocturnal sleep equal to 6–7 hours (hazard ratio: 1.50 [95% confidence interval: 1.04–2.17]; P = 0.03). Continued investigation of the association of timing and duration of sleep with hemodialysis patient outcomes is warranted.     

Obstructive sleep apnoea among professional taxi drivers: A pilot study

Purpose

This study aimed to describe the distribution of risk factors for obstructive sleep apnoea syndrome (OSAS) among taxi drivers, and to investigate differences by ethnicity in OSAS symptoms among drivers.

Methods

A two-page postal questionnaire was completed by 241 professional taxi drivers from Wellington, New Zealand. Obstructive sleep apnoea syndrome was defined as having an estimated 15 or more respiratory disturbances, per hour of sleep (Respiratory Disturbance Index (RDI) ≥ 15) and self-reported daytime sleepiness.

Results

Pacific and Māori taxi drivers were more likely to have symptoms and risk factors for OSAS, compared to non-Māori non-Pacific drivers. In particular, Pacific drivers had a significantly increased pre-test probability of having moderate-severe OSA (RDI ≥ 15).

Conclusions

Some professional taxi drivers are at increased risk for moderate-severe OSAS, especially Pacific and Māori taxi drivers. Untreated OSAS increases motor vehicle crash risk, so these findings have implications for the health and safety of drivers and their passengers. They suggest a need for more comprehensive research to guide policy on medical examinations required for licensing professional drivers as fit to drive.     

Young drivers who obtained their licence after an intensive driving course report more incidents than drivers with a traditional driver education

This paper studies the effectiveness of intensive driving courses; both in driving test success and safe driving after passing the driving test. The so-called intensive driving course (IDC) consists of a limited number of consecutive days in which the learner driver takes driving lessons all day long; and is different from traditional training in which lessons are spread out over several months and in which learners take one or two driving lessons of approximately 1 h each per week. Our study indicates that – in the first two years of their driving career – IDC drivers (n = 35) reported an incident significantly more often (43%) than 351 drivers who obtained their driving licence after traditional training (26%). Our study also indicates that the IDC drivers underwent almost the same number of training hours as the drivers who had traditional training, although spacing of these hours was different. There was no difference in the number of attempts to pass the driving test. We did not find any evidence that a self-selection bias was responsible for the difference in reported number of incidents.     

Evaluating a novice driver and pre-driver road safety intervention

Intervention or evaluation studies represent a small proportion of traffic psychology research. The current study evaluated the effectiveness of a road safety intervention by measuring attitudes toward unsafe driving behaviors and risk perception. A sample of high school students (n = 133) participated in a road safety intervention program focusing on attitudes and risk perceptions of young people as novice drivers, pre-drivers, and passengers. This sample was compared with a matched sample of students who did not take the program (n = 172) on their attitudes and perceived risk toward unsafe driving, both prior to the program (T1), immediately after the program (T2), and at 6-week follow-up (T3). While no changes in attitudes toward unsafe driving were found for the control group, the intervention group reported riskier attitudes toward unsafe driving behaviors from T1 to T2 and T3. No differences were found from T1 to T3 in perceived risk toward unsafe driving for either the intervention or control groups. Implications of the study include encouraging a higher rate of road safety program evaluations, leading to better understanding of the effectiveness of road safety intervention programs and how they may be designed and delivered to ensure lower engagement in unsafe driving behaviors by young drivers.     

Self-rated driving and driving safety in older adults

Many U.S. states rely on older adults to self-regulate their driving and determine when driving is no longer a safe option. However, the relationship of older adults’ self-rated driving in terms of actual driving competency outcomes is unclear. The current study investigates self-rated driving in terms of (1) systematic differences between older adults with high (good/excellent) versus low (poor/fair/average) self-ratings, and (2) the predictive nature of self-rated driving to adverse driving outcomes in older adults (n = 350; mean age 73.9, SD = 5.25, range 65–91). Adverse driving outcomes included self-reported incidences of (1) being pulled over by the police, (2) receiving a citation, (3) receiving a recommendation to cease or limit driving, (4) crashes, and (5) state-reported crashes. Results found that older drivers with low self-ratings reported more medical conditions, less driving frequency, and had been given more suggestions to stop/limit their driving; there were no other significant differences between low and high self-raters. Logistic regression revealed older drivers were more likely to have a state-reported crash and receive a suggestion to stop or limit driving. Men were more likely to report all adverse driving outcomes except for receiving a suggestion to stop or limit driving. Regarding self-rated driving, older adults with high ratings were 66% less likely (OR = 0.34, 95% CI = 0.14–0.85) to have received suggestions to limit or stop driving after accounting for demographics, health and driving frequency. Self-ratings were not predictive of other driving outcomes (being pulled over by the police, receiving a citation, self-reported crashes, or state-reported crashes, ps > 0.05). Most older drivers (85.14%) rated themselves as either good or excellent drivers regardless of their actual previous citation or crash rates. Self-rated driving is likely not related to actual driving proficiency as indicated by previous crash involvement in older adults. Suggestions from other individuals to limit or cease driving may be more influential on self-ratings.     

Pre-licensed driving experience and car crash involvement during the learner and restricted,licence stages of graduated driver licensing: Findings from the New Zealand Drivers Study

Objective

The aim of this study was to determine whether pre-licence driving experiences, that is driving before beginning the licensing process, increased or decreased crash risk as a car driver, during the learner or the restricted licence stages of the graduated driver licensing system (GDLS).

Method

Study participants were 15–24 year old members of the New Zealand Drivers Study (NZDS) – a prospective cohort study of newly licensed car drivers. The interview stages of the NZDS are linked to, the three licensing stages of the GDLS: learner, restricted and full. Baseline demographic (age, ethnicity, residential location, deprivation), personality (impulsivity, sensation seeking, aggression) and, behavioural data, (including pre-licensed driving behaviour), were obtained at the learner licence interview. Data on distance driven and crashes that occurred at the learner licence and restricted licence stages, were reported at the restricted and full licence interviews, respectively. Crash data were also obtained from police traffic crash report files and this was combined with the self-reported crash data. The analysis of the learner licence stage crashes, when only supervised driving is allowed, was based on the participants who had passed the restricted licence test and undertaken the NZDS, restricted licence interview (n = 2358). The analysis of the restricted licence stage crashes, when unsupervised driving is first allowed, was based on those who had passed the full licence test and completed the full licence interview (n = 1428).

Results

After controlling for a range of demographic, personality, behavioural variables and distance driven, Poisson regression showed that the only pre-licence driving behaviour that showed a consistent relationship with subsequent crashes was on-road car driving which was associated with an increased risk of being the driver in a car crash during the learner licence period.

Conclusion

This research showed that pre-licensed driving did not reduce crash risk among learner or restricted licensed drivers, and in some cases (such as on-road car driving) may have increased risk. Young people should be discouraged from the illegal behaviour of driving a car on-road before licensing.     

Hostility,driving anger,and dangerous driving: The emerging role of hemispheric preference

Background

Various studies have implicated psychosocial variables (e.g., hostility) in risk of dangerous driving and traffic accidents. However, whether these variables are related to more basic neurobiological factors, and whether such associations have implications for the modification of psychosocial risk factors in the context of driving, have not been examined in depth. This study examined the relationship between hemispheric preference (HP), hostility and self-reported dangerous driving, and the ability to affect driving anger via hemisphere activating cognitive exercises (HACE).

Methods

In Study 1, 254 Turkish students completed questionnaires of hostility, HP and driving behavior. In Study 2, we conducted a “proof of concept” experimental study, and tested effects of left, right and neutral HACE on driving anger, by exposing N = 650 Turkish students to written scenarios including either logical (left hemisphere), visuo-spatial (right hemisphere) or “mild doses” of both types of contents (control).

Results

In Study 1, left-HP was associated with higher hostility and with more dangerous driving, and hostility mediated the relationship between L-HP and reported driving behavior. In Study 2, only right-HACE led to immediate significant reductions in self-reported driving anger.

Conclusions

Left-HP is related to hostility and to dangerous driving, and it may be possible to partly reduce driving anger by right-HACE. Future studies must replicate these findings with objective measures, more enduring interventions and longer follow-ups.     

How reinforcement sensitivity and perceived risk influence young drivers’ reported engagement in risky driving behaviors

Gray's reinforcement sensitivity theory (RST), implementing Carver and White's behavior inhibition system (BIS) and behavior approach system (BAS) scales, was used to predict reported engagement in 10 risky driving behaviors: speeding (2 levels), driving under the influence of alcohol, racing other vehicles, cell phone use (hand-held and hands free), tailgating, unsafe overtaking, driving while fatigued, and not wearing a seatbelt. Participants were 165 young male and female (n = 101) drivers aged 17–25 years who held a valid Australian driver's license. Effects of the explanatory variables and specific risk perceptions upon engagement in the reported risky driving behaviors were examined using SEM analyses. Also of interest was whether perceived risk mediated the relationship between the personality variables and reported engagement in risky driving behaviors. RST variables, negative reactivity, reward responsiveness and fun seeking, accounted for unique variance in young drivers’ perceived risk. Reward responsiveness and perceived risk accounted for unique variance in young drivers’ reported engagement in risky driving behaviors. Negative reactivity was completely mediated by perceived risk in its negative relationship with reported engagement. To better understand driving related risk decision making, future research could usefully incorporate drivers’ motivation systems. This has the potential to lead to more tailored approaches to identifying risk-prone drivers and provide information for the development and implementation of media campaigns and educational programs.     

Which visual measures affect change in driving difficulty after first eye cataract surgery?

Objective

To investigate self-reported driving difficulty before and after first eye cataract surgery and determine which visual measures are associated with changes in self-reported driving difficulty after surgery.

Methods

A cohort of 99 older drivers with bilateral cataract were assessed the week before and 12 weeks after first eye cataract surgery. Visual measures including visual acuity, contrast sensitivity, stereopsis and useful field of view were assessed. Self-reported driving difficulty was measured via the Driving Habits Questionnaire. Cognitive status was assessed using the Mini Mental State Examination. Regression analysis was undertaken to determine the association between changes in visual measures and self-reported driving difficulty after first eye cataract surgery.

Results

Overall, self-reported driving difficulty improved after first eye cataract surgery. However, 16% of participants did not improve and driving difficulty worsened in 11% following surgery. Improvement in driving difficulty score after first eye cataract surgery was associated with improved contrast sensitivity in the operated eye (p < 0.001), new glasses after surgery (p < 0.001), and fewer chronic health conditions (p = 0.016).

Conclusion

Contrast sensitivity rather than visual acuity was a significant factor affecting change in self-reported driving difficulty after first eye cataract surgery for bilateral patients. This has implications for driver licensing authorities worldwide that rely heavily on visual acuity as a measure of visual fitness to drive.