Anna Chevalier

Early childhood obesity: Association with healthcare expenditure in Australia

To determine whether overweight or obesity among children (aged 2 to ≤5 years) is associated with direct healthcare costs, after adjusting for child, household, and socioeconomic characteristics.

Behind the wheel: confidence and naturalistic measures of driving exposure among older drivers

Driving confidence is thought to influence driving exposure among older drivers and may affect driver safety. Studies to date have relied primarily on self-reported measures of driving exposure to explore this relationship. The objective of this study was to explore the relationship between confidence and actual driving exposure among drivers aged 75 years and older. A cross-sectional analysis of survey data (function, confidence, personal circumstances) and naturalistic measures of driving exposure was conducted with 380 older drivers in northwest Sydney, Australia. Driving exposure, including total distance traveled, radius of travel from home, average trip distance, and nighttime driving, was measured for 1 week. The mean age of participants was 80 years. More males (n = 230) than females (n = 150) were enrolled. Successful instrumentation was achieved for 362 of 380 vehicles. Driving confidence was found to be independently associated with the farthest distance traveled from home, average trip distance, and night driving. Older drivers with lower confidence took shorter trips, stayed closer to home, and were less likely to drive at night. This study provided evidence of a responsive process in which drivers with lower confidence and poorer function were found to have different patterns of driving—specifically, driving in familiar areas, during daylight hours, and closer to home. It is likely that drivers in later life change their driving patterns to preserve safety and mobility. This understanding will help policy makers and educators shape responsive programs that help older drivers drive safely for as long as possible.

Behind the wheel : predictors of driving exposure in older drivers

To explore and deepen understanding of factors influencing driving exposure for older drivers.

Predictors of older drivers’ involvement in rapid deceleration events

Rapid deceleration occurs when substantial force slows the speed of a vehicle. Rapid deceleration events (RDEs) have been proposed as a surrogate safety measure. As there is concern about crash involvement of older drivers and the effect of age-related declining visual and cognitive function on driving performance, we examined the relationship between RDEs and older drivers vision, cognitive function and driving confidence, using naturalistic driving measures. Participants aged 75 to 94 years had their vehicle instrumented for 12 months. To minimise the chance of identifying false positives, accelerometer data was processed to identify RDEs with a substantial deceleration of >750 milli-g (7.35m/s2). We examined the incidence of RDEs amongst older drivers, and how this behaviour is affected by differences in age; sex; visual function, cognitive function; driving confidence; and declines over the 12 months. Almost two-thirds (64%) of participants were involved in at least one RDE, and 22% of these participants experienced a meaningful decline in contrast sensitivity during the 12 months. We conducted regression modelling to examine associations between RDEs and predictive measures adjusted for (i) duration of monitoring and (ii) distance driven. We found the rate of RDEs per distance increased with age; although, this did not remain in the multivariate model. In the multivariate model, we found older drivers who experienced a decline in contrast sensitivity over the 12 months and those with lower baseline driving confidence were at increased risk of involvement in RDEs adjusted for distance driven. In other studies, contrast sensitivity has been associated with increased crash involvement for older drivers. These findings lend support for the use of RDEs as a surrogate safety measure, and demonstrate an association between a surrogate safety measure and a decline in contrast sensitivity of older drivers.

Naturalistic speeding data: Drivers aged 75 years and older

The data presented in this article are related to the research article entitled “A longitudinal investigation of the predictors of older drivers׳ speeding behavior” (Chevalier et al., 2016) [1], wherein these speed events were used to investigate older drivers speeding behavior and the influence of cognition, vision, functional decline, and self-reported citations and crashes on speeding behavior over a year of driving. Naturalistic speeding behavior data were collected for up to 52 weeks from volunteer drivers aged 75–94 years (median 80 years, 52% male) living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Global Positioning System (GPS) data were recorded at each second and determined driving speed through triangulation of satellite collected location data. Driving speed data were linked with mapped speed zone data based on a service-provider database. To measure speeding behavior, speed events were defined as driving 1 km/h or more, with a 3% tolerance, above a single speed limit, averaged over 30 s. The data contains a row per 124,374 speed events. This article contains information about data processing and quality control.

Naturalistic rapid deceleration data: Drivers aged 75 years and older

The data presented in this article are related to the research manuscript “Predictors of older drivers’ involvement in rapid deceleration events”, which investigates potential predictors of older drivers’ involvement in rapid deceleration events including measures of vision, cognitive function and driving confidence (A. Chevalier et al., 2016) [1]. In naturalistic driving studies such as this, when sample size is not large enough to allow crashes to be used to investigate driver safety, rapid deceleration events may be used as a surrogate safety measure. Naturalistic driving data were collected for up to 52 weeks from 182 volunteer drivers aged 75–94 years (median 80 years, 52% male) living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Accelerometer data were recorded 32 times per second and Global Positioning System (GPS) data each second. To measure rapid deceleration behavior, rapid deceleration events (RDEs) were defined as having at least one data point at or above the deceleration threshold of 750 milli-g (7.35 m/s2). All events were constrained to a maximum 5 s duration. The dataset provided with this article contains 473 events, with a row per RDE. This article also contains information about data processing, treatment and quality control. The methods and data presented here may assist with planning and analysis of future studies into rapid deceleration behaviour using in-vehicle monitoring.

Improving hospital death certification in Viet Nam: results of a pilot study implementing an adapted WHO hospital death report form in two national hospitals

Background Viet Nam does not have a system for the national collection of death data that meets international requirements for mortality reporting. It is identified as a ‘no-report’ country by the WHO. Verbal autopsy reports are used in the community but exclude deaths in hospitals. Methods This project was undertaken in Bach Mai National General Hospital and Viet Duc Surgical and Trauma Hospital in Viet Nam from 1 March 2013 to 31 March 2015. In phase 1, a modified hospital death report form, consistent with the International Statistical Classification of Diseases and Related Health Problems, 10th Revision, was developed. Small group training in use of the report form was delivered to 427 doctors. In phase two, death data were collected, collated and analysed. In phase three, a random sample (7%) of all report forms was checked for accuracy and completeness against medical records. Findings During the 23 months of the study, 3956 deaths were recorded. Across both hospitals, 222 distinct causes of deaths were recorded. Traumatic cerebral oedema was the immediate cause of death (15% of cases, 575/3956 patients), followed by septic shock (13%, 528/3956), brain compression (11%, 416/3956), intracerebral haemorrhage (8%, 336/3956) and pneumonia (5%, 186/3956); 67% (2639/3956) of patients were discharged home to die and 33% (1314/3956) of deaths were due to a road traffic accident, or injury at home or at work. Conclusions This study confirms the viability of implementing a death report form system compliant with international standards in hospitals in Viet Nam and provides the foundation for introducing a national death report form scheme. These data are critical to comprehensive knowledge of causes of death in Viet Nam. Death data about patients discharged home to die is presented for the first time, with implications for countries where this is a cultural preference.

Effects of a Safe Transportation Educational Program for Older Drivers on Driving Exposure and Community Participation: A Randomized Controlled Trial

To ascertain whether a safe‐transportation program can change driving exposure while maintaining community participation of older drivers.

Improving hospital death certification in Vietnam: results of a pilot study of injury-related fatalities

Background Vietnam has prioritised the establishment of a civil registration system for deaths but as yet is unable to report accurate national statistics for the population of 93.5 million people due to inadequate mortality data. Verbal autopsy data suggest that injury is a third leading cause of death (by International Statistical Classification of Diseases and Related Health Problems 10th Revision chapters) in Vietnam, with road traffic injuries in particular a significant and increasing challenge. The study aims to present a more accurate profile of the number and probable causes of these deaths based on data collected hospitals using a version of the WHO death certificate modified for the Vietnamese context. Methods Death data collected from Viet Duc Surgical and Trauma Hospital in Vietnam between 1 March 2013 to 31 March 2015 was analysed to explore the number and probable causes of deaths for deaths resulting from an injury. Results A total of 1616 deaths were recorded for Viet Duc Hospital, of which 73% (1181/1616) were associated with an injury. Most (83%; n=871/1049) injury-related deaths for which immediate cause of death was documented were as a result of head/brain injuries. Injury-related deaths were most commonly caused by from traffic accidents (72%, 853/1181). The majority of patients suffering injury-related deaths were discharged home to die (93%, 1097/1181). Conclusion The study confirms some findings from previous studies about deaths from injuries, while disagreeing with others, highlighting the challenge for Vietnam in collecting these data. Gathering detailed death data provides essential evidence on which to base decisions about allocation of government funding and policy for injury prevention and treatment.

Sex differences evident in self-reported but not objective measures of driving

It has been consistently reported that women self-regulate their driving more than men. Volunteer drivers aged 75 years and older from the suburban outskirts of Sydney, Australia joined a longitudinal study in 2012-2014. GPS in-vehicle monitoring was used to objectively measure driving and surveys of driving patterns. The study included 343 drivers (203/343, 59% men) with an average age of 80 years. Our results revealed that men were 3.85 times more likely to report driving beyond their local shire during the past year (95% CI 2.03-5.72) and 1.81 times more likely to report that they do not avoid night driving (95% CI 1.21-3.22). In contrast sex was not predictive of any objective measure of driving during a one-week period of monitoring. These findings suggest that men and women report different self-regulation practices but that actual driving exposure is quite similar. These findings can inform strategies to promote safe mobility.