Outcome evaluation of the p drivers Program: Randomised controlled trial of a program to improve safe driving among novice drivers

BACKGROUND

Globally, road traffic crashes are the leading cause of death for young adults. The P Drivers Project was a trial of a behavioural change program developed for, and targeted at, young Australian drivers in their initial months of solo driving when crash risk is at its highest.

METHODS

In a parallel group randomised controlled trial, drivers (N = 35,109) were recruited within 100 days of obtaining their probationary licence (allowing them to drive unaccompanied) and randomised to an intervention or control group. The intervention was a 3 to 6-week multi-stage driving behaviour change program (P Drivers Program). Surveys were administered at three time points (pre-Program, approximately one month post-Program and at 12 months after). The outcome evaluation employed an on-treatment analysis comprising the 2,419 intervention and 2,810 control participants who completed all required activities, comparing self-reported crashes and police-reported casualty crashes (primary outcome), infringements, self-reported attitudes and behaviours (secondary outcomes) between groups.

RESULTS

The P Drivers Program improved awareness of crash risk factors and intentions to drive more safely, relative to the controls; effects were maintained after 12-months. However, the Program did not reduce self-reported crashes or police-reported casualty crashes. In addition, self-reported violations, errors and risky driving behaviours increased in the intervention group compared to the control group as did recorded traffic infringements. This suggests that despite the Program increasing awareness of risky behaviour in novice drivers, behaviour did not improve. This reinforces the need to collect objective measures to accompany self-reported behaviour and intentions.

CONCLUSIONS

The P Drivers Program was successful in improving attitudes toward driving safety but the negative impact on behaviour, lack of effect on crashes, and the large loss to follow-up fail to support the use of a post-licensing behaviour change program to improve novice driver behaviour and reduce crashes.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: 363,293 (ANZCTR, 2012).

Sound localisation of low- and high-frequency sounds in cochlear implant users with single-sided deafness

OBJECTIVE

Localisation of low- and high-frequency sounds in single-sided deaf cochlear implant users was investigated using noise stimuli designed to mitigate monaural localisation cues.

DESIGN

Within subject design. Sound source localisation was tested in the horizontal plane using an array of seven loudspeakers along the azimuthal angle span from -90° to +90°. Stimuli were broadband noise and high- and low-frequency noise.

STUDY SAMPLE

Twelve adult subjects with single-sided deafness participated in the study. All had normal hearing in the healthy ear and were supplied with a cochlear implant (CI) in their deaf ear.

RESULTS

With broadband noise, the mean angular localisation error was 39° in aided condition as compared to a median angular error of 83.6° when the speech processor was not worn. For high-frequency noise, the median angular error was 30° and for low-frequency noise, it was 46° in the CI-aided condition.

CONCLUSIONS

Single-sided deaf CI users show the best sound localisation for high-frequency sounds. This supports the view that interaural level differences are dominant for sound localisation in these listeners. Nonetheless, a limited ability to localise low-frequency sounds was observed, which may be based on the supportive perception of interaural time differences.

Images from the surface of asteroid Ryugu show rocks similar to carbonaceous chondrite meteorites

The near-Earth asteroid (162173) Ryugu is a 900-m-diameter dark object expected to contain primordial material from the solar nebula. The Mobile Asteroid Surface Scout (MASCOT) landed on Ryugu's surface on 3 October 2018. We present images from the MASCOT camera (MASCam) taken during the descent and while on the surface. The surface is covered by decimeter- to meter-sized rocks, with no deposits of fine-grained material. Rocks appear either bright, with smooth faces and sharp edges, or dark, with a cauliflower-like, crumbly surface. Close-up images of a rock of the latter type reveal a dark matrix with small, bright, spectrally different inclusions, implying that it did not experience extensive aqueous alteration. The inclusions appear similar to those in carbonaceous chondrite meteorites.

Improved interaural timing of acoustic nerve stimulation affects sound localization in single-sided deaf cochlear implant users

The main impairment associated with single-sided deafness (SSD) is the loss of binaural hearing. Currently, the most effective treatment to compensate for this deficit is to supply patients suffering from SSD with a cochlear implant (CI) in the deaf ear. With this approach binaural hearing abilities can be restored to a certain extent, which is expressed in an improvement in such patients with regard to sound source localization and speech comprehension in noise after receipt of a CI. However, binaural performance of these listeners does not reach the level of normal-hearing listeners. One of the reasons for this might be that the electrical stimulation via CI and the physiological stimulation via the intact ear are not synchronized: the CI transmits the information to the auditory nerve with different timing than does the intact inner ear. As a result, there is a timing mismatch of the information transfer between the left and the right side, which may account for the limited binaural performance. The effective mismatch in timing depends on the CI system because of different stimulation strategies implemented in devices from different manufacturers. For the particular CI device used in this study (MED-EL Mi1000/Mi1200) electrical stimulation led to faster activation of the auditory nerve than natural for a wide frequency range. In particular, electrical stimulation was about 1 to up to 2 ms ahead of time for frequencies above 1.5 kHz. Hence, it was hypothesized that information transfer between the left and the right ear can be tuned by delaying the CI signal. The goal of the present study was to investigate whether such a delay in the CI signal affects binaural performance of CI users with SSD. For this purpose, sound source localization and speech perception in noise were tested in a sample of 12 CI users with SSD (mean age 51 ± 12 years). The tests were performed for four different delay times of the CI signal applied spontaneously (0.5, 1, 2 and 4 ms) and for the base line condition "no delay" in the CI signal (i.e. everyday use). It was found that delaying the signal had a significant impact on sound source localization. Speech perception in noise was affected, but less pronounced than was sound localization. Regarding sound source localization, a signal delay of 1 ms applied to this particular CI device produced the best performance in our patients. It is concluded that improving the synchronisation between the CI-transferred signal and the naturally transferred signal could increase binaural hearing performance in CI users with SSD.

Stapedius Reflex in Patients with an Inner Ear Prosthesis

The stapedius reflex elicited by electrical stimulation was investigated in 21 deaf individuals supplied with an inner ear prosthesis. All patients were implanted with the Vienna cochlear implant using intra or extracochlear electrodes. Analog stimulation with sinus bursts of various durations (25, 50, 100, 300, 500 ms) and frequencies (125, 500, 1000, 2000 Hz) was used. The time course of the contralateral acoustic reflex was monitored using a fast-response impedance meter. The stapedius reflex was observed in about half of the cases. Reflex threshold was observed at a stimulation level close to uncomfortable loudness. The time course in case of electrical stimulation differs in some aspects (rise time, onset) from acoustic stimulation in hearing individuals. Temporal integration of the stapedius reflex was observed also in case of electrostimulation through the cochlear implant.

Are older drivers' driving patterns during an on-road driving task representative of their real-world driving patterns?

OBJECTIVE

The current study investigated whether older drivers' driving patterns during a customized on-road driving task were representative of their real-world driving patterns.

METHODS

Two hundred and eight participants (male: 68.80%; mean age = 81.52 years, SD = 3.37 years, range = 76.00-96.00 years) completed a customized on-road driving task that commenced from their home and was conducted in their own vehicle. Participants' real-world driving patterns for the preceding 4-month period were also collected via an in-car recording device (ICRD) that was installed in each participant's vehicle.

RESULTS

During the 4-month period prior to completing the on-road driving task, participants' median real-world driving trip distance was 2.66 km (interquartile range [IQR] = 1.14-5.79 km) and their median on-road driving task trip distance was 4.41 km (IQR = 2.83-6.35 km). Most participants' on-road driving task trip distances were classified as representative of their real-world driving trip distances (95.2%, n = 198).

CONCLUSIONS

These findings suggest that most older drivers were able to devise a driving route that was representative of their real-world driving trip distance. Future research will examine whether additional aspects of the on-road driving task (e.g., average speed, proportion of trips in different speed zones) are representative of participants' real-world driving patterns.

Cometary science. The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta

The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument on board the Rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko. The very low reflectance of the nucleus (normal albedo of 0.060 ± 0.003 at 0.55 micrometers), the spectral slopes in visible and infrared ranges (5 to 25 and 1.5 to 5% kÅ(-1)), and the broad absorption feature in the 2.9-to-3.6-micrometer range present across the entire illuminated surface are compatible with opaque minerals associated with nonvolatile organic macromolecular materials: a complex mixture of various types of carbon-hydrogen and/or oxygen-hydrogen chemical groups, with little contribution of nitrogen-hydrogen groups. In active areas, the changes in spectral slope and absorption feature width may suggest small amounts of water-ice. However, no ice-rich patches are observed, indicating a generally dehydrated nature for the surface currently illuminated by the Sun.

Effect of wearing a ski helmet on perception and localization of sounds

Helmet use on ski slopes has steadily increased worldwide over the past years. A common reason reported for helmet non-use, however, is impaired hearing. Therefore, an intra-subject design study was conducted to compare hearing thresholds and sound source localization of 21 adults with normal hearing in an anechoic chamber when wearing a ski helmet and ski goggles or wearing a ski cap and ski goggles to the condition head bare. Hearing thresholds while wearing a ski helmet (6.8 ± 1.6 dB HL) and ski cap (5.5 ± 1.6 dB HL) were significantly different (p = 0.030, d = 0.44). Compared to head bare (2.5 ± 1.2 dB HL), a significant difference was found for the ski helmet only (p = 0.040, d = 1.57). Regarding sound source localization, correct scores in the condition head bare (90%) showed a highly significant difference compared with those of condition cap (65%) and helmet (58%), respectively (p < 0.001; d > 2.5). Compared to the ski cap, wearing the helmet significantly reduced correct scores (p = 0.020, d = 0.59) irrespective of the tested sound pressure levels. In conclusion, wearing a ski helmet impairs hearing to a small though significantly greater extent compared with a cap, the degree, however, being less than what is termed as a hearing impairment. Compared to the condition head bare, wearing a ski cap or a ski helmet significantly reduced one's ability of sound source localization.

Towards a consensus on a hearing preservation classification system

CONCLUSION

The comprehensive Hearing Preservation classification system presented in this paper is suitable for use for all cochlear implant users with measurable pre-operative residual hearing. If adopted as a universal reporting standard, as it was designed to be, it should prove highly beneficial by enabling future studies to quickly and easily compare the results of previous studies and meta-analyze their data.

OBJECTIVES

To develop a comprehensive Hearing Preservation classification system suitable for use for all cochlear implant users with measurable pre-operative residual hearing.

METHODS

The HEARRING group discussed and reviewed a number of different propositions of a HP classification systems and reviewed critical appraisals to develop a qualitative system in accordance with the prerequisites.

RESULTS

The Hearing Preservation Classification System proposed herein fulfills the following necessary criteria: 1) classification is independent from users' initial hearing, 2) it is appropriate for all cochlear implant users with measurable pre-operative residual hearing, 3) it covers the whole range of pure tone average from 0 to 120 dB; 4) it is easy to use and easy to understand.

[Results of hearing screenings in 14- to 15-year old adolescents]

BACKGROUND

A hearing screening among 14- to 15-year-old pupils was performed to estimate the number of hearing-impaired individuals in the adolescent population.

MATERIALS AND METHODS

A total of 1,298 pupils from 30 schools in Tyrol (Austria) participated in the screening. Hearing tests were performed in a silent room at the school. Sinus tones at frequencies 0.5/1/2/4/6 kHz and at levels of 25/20/20/20/20 dB HL, respectively, were delivered via headphones to either ear. Failure of screening was defined as not hearing one or more frequencies in one or both ears.

RESULTS

The screening was failed by 16.3% of the pupils. There was a small but not significant difference between males and females (17.0 vs. 15.2%). Most of the pupils failed at only one frequency (9.6%). Failing at two or more frequencies in the same ear occurred in 3.9% of the pupils, thereof in 1.1% bilaterally.

CONCLUSION

As the specificity of our screening is limited, false-positive results may result. Thus, the rate of hearing deficits in our sample is probably a bit lower than indicated by the figures above. Most of the adolescents who failed the screen failed at only one frequency. These subjects have a small elevation of their hearing threshold, not a hearing loss in the sense of a raised averaged threshold. A hearing loss in the latter sense is supposed to be present in only very few percent of adolescents, a bilateral hearing loss in perhaps less than 1%.

[Psychotherapy and obesity: strategies, challenges and possibilities]

One fifth of the German population is obese with increasing prevalence. Psychotherapy plays an important role in weight loss programmes. Cognitive behaviour therapy, targeting lifestyle changes, including exercise and eating behaviour, is the evidence-based treatment of choice. Especially the lack of motivation or absence of weight loss, further weight gain or psychosocial burden makes psychotherapy essential. The treatment of a comorbid binge eating disorder should be initiated prior to focusing on weight loss. Remarkably difficult stages in the treatment of obesity are the initiation of changes as well as the maintenance of the achieved weight loss. Internet-based attempts will become increasingly important.

Risk factors for injury in a national cohort of 87,134 Thai adults

BACKGROUND

Information is needed regarding risk factors associated with injury. In middle- and lower-income countries, injury studies have focused on road traffic injuries and less attention has been given to other types of injuries.

METHODS

This study is part of overarching health-risk transition research in Thailand with a large national cohort study that began in 2005 (n = 87,134). Associations between potential determinants and overall injury were measured, as well as injury by location (transport, home, work and sport), using data gathered from the baseline questionnaire.

RESULTS

In total, 21.5% of the cohort reported at least one incidence of injury over the last 12 months. Risk factors associated with injury were being male [odds ratio (OR) 1.20], having lower income (OR 1.70), having problems with vision (OR 1.46), having epilepsy (OR 3.02), having depression/anxiety (OR 1.62), poor self-assessed health (OR 1.68), being obese (OR 1.24) and death of father due to injury (OR 1.59). Analysis of injury by location provided more specific information on risk factors. For example, females were more likely to report injuries at home, while males, urban residents and regular alcohol drinkers were more likely to report transport injuries.

CONCLUSIONS

The risk of injury in Thailand varies considerably by location, sociodemographic group and several categories of co-existing morbidities. Such epidemiological information identifying risk factors for injury is useful for designing targeted injury prevention programmes in Thailand and other middle-income countries.

Surface composition of Hyperion

Hyperion, Saturn's eighth largest icy satellite, is a body of irregular shape in a state of chaotic rotation. The surface is segregated into two distinct units. A spatially dominant high-albedo unit having the strong signature of H2O ice contrasts with a unit that is about a factor of four lower in albedo and is found mostly in the bottoms of cup-like craters. Here we report observations of Hyperion's surface in the ultraviolet and near-infrared spectral regions with two optical remote sensing instruments on the Cassini spacecraft at closest approach during a fly-by on 25-26 September 2005. The close fly-by afforded us the opportunity to obtain separate reflectance spectra of the high- and low-albedo surface components. The low-albedo material has spectral similarities and compositional signatures that link it with the surface of Phoebe and a hemisphere-wide superficial coating on Iapetus.

Release of volatiles from a possible cryovolcano from near-infrared imaging of Titan

Titan is the only satellite in our Solar System with a dense atmosphere. The surface pressure is 1.5 bar (ref. 1) and, similar to the Earth, N2 is the main component of the atmosphere. Methane is the second most important component, but it is photodissociated on a timescale of 10(7) years (ref. 3). This short timescale has led to the suggestion that Titan may possess a surface or subsurface reservoir of hydrocarbons to replenish the atmosphere. Here we report near-infrared images of Titan obtained on 26 October 2004 by the Cassini spacecraft. The images show that a widespread methane ocean does not exist; subtle albedo variations instead suggest topographical variations, as would be expected for a more solid (perhaps icy) surface. We also find a circular structure approximately 30 km in diameter that does not resemble any features seen on other icy satellites. We propose that the structure is a dome formed by upwelling icy plumes that release methane into Titan's atmosphere.

Role of class D L-type Ca2+ channels for cochlear morphology

Voltage-gated Ca(2+) channels formed by subunits (class D Ca(2+) channels) tightly regulate neurotransmitter release from cochlear inner hair cells (IHCs) by controlling the majority of depolarisation-induced Ca(2+) entry. We have recently shown that the absence of these channels can cause deafness and degeneration of outer hair cells (OHCs) and IHCs in alpha1D-deficient mice (alpha1D(-/-)) (Platzer et al., 2000. Cell 102, 89-97). We investigated the time-dependent patterns of degeneration during postnatal development in the alpha1D(-/-) mouse cochlea using light and electron microscopy. At postnatal day 3 (P3), electron microscopy revealed no morphological aberrations in sensory cells, in afferent as well as in efferent nerve endings. But at P7 we observed a beginning degeneration of afferent nerve fibres by electron microscopy. By P15, we found a loss of OHCs in apical turns but electron microscopy revealed no ultrastructural changes in IHCs and efferent axons as compared to C57 black control animals (C57BL). We demonstrated by serial ultrathin sectioning of 15 days old alpha1D(-/-) mice that intact efferent nerve fibres formed direct contacts with IHCs as the degeneration of afferent nerve fibres progressed. We also saw a notable degeneration of spiral ganglion cells at P15. By 8 months, nearly all spiral ganglion and sensory cells of the organ of Corti were absent. Random ultrathin sectioning gave the impression that synaptic bodies abundant in wild-type animals were absent in nearly all alpha1D(-/-) mice investigated. We conclude that besides presumably reduced synaptic bodies the absence of class D L-type Ca(2+) channels does not prevent morphological development of the cochlea until P3 but may cause cochlear degeneration thereafter. The observed pattern of degeneration involves afferent nerve fibres (P7) followed by cell bodies in the spiral ganglion (P15), OHCs (P15) and IHCs (after P15).