Road vehicle collision suicide in Australia: Trends, collision types, and individual characteristics.

BACKGROUND: Suicide by road vehicle collision in Australia is under-explored with mixed findings. We aimed to address this research gap by examining time trends, different types of vehicle collision, and individual characteristics related to vehicle-collision suicide. METHOD: We retrospectively analyzed deaths by suicide between 1st January 2001 and 31st December 2017 in Australia, using coronial records from the National Coronial Information System. The travel mode used and collision counterpart were retrieved from records of death by vehicle-collision suicide using all available information. We conducted negative binomial regression analysis to examine annual changes in suicide rate by vehicle collision on a public road (N = 640) and other methods of suicide (N = 41,890), and logistic regression analysis to examine individual characteristics associated with the likelihood of dying by suicide via road vehicle collision. RESULTS: Overall, the national suicide rate involving road vehicle collision significantly increased, while the rate by other methods significantly decreased. Drivers accounted for 61% of suicide events by vehicle collision, of which 72% were single-vehicle collisions (commonly involving a tree). For multiple-vehicle collision suicide events, 82% involved collision with a truck. Pedestrians accounted for more than one-third of suicide events, of which 58% involved collision with a truck and 23% involved collision with a car/van. Individuals who were male (odds ratio 1.15; 95% CI 0.88-1.50), aged <25 years old (odds ratio 5.27; 95% CI 3.05-9.10), non-Indigenous (odds ratio 3.36; 95% CI 1.71-6.62), and born overseas (odds ratio 1.40; 95% CI 1.10-1.79) were more likely to die by vehicle-collision suicide than by other methods of suicide. CONCLUSIONS: This study provides a better understanding of road vehicle collision suicide in Australia and informs future research directions on topic. Our findings can be used to inform suicide prevention initiatives to reduce vehicle-collision suicide deaths.

Indexation of Tobacco Excise and Customs Duty and Smoking Prevalence Among Australian Adults, 2001-2010: A Serial Cross-sectional Study.

INTRODUCTION: Australia's excise and customs duty on tobacco has been automatically increased biannually since 1984. Increases in duty on par with inflation ensured that tobacco stayed at least as costly as other goods. This would be expected to maintain, rather than drive down, smoking prevalence. We examined the association between smoking prevalence and duty over a 10-year period. METHODS: Using monthly data from five Australian capital cities, collected from March 2001 to March 2010 among Australians aged at least 18 years, multiple linear regression modeled associations between smoking prevalence and the two components (duty and non-duty) of the recommended retail price of an average packet of cigarettes, adjusting for policy covariates. RESULTS: Prevalence declined from 23.6% in March 2001 to 17.0% in March 2010 [absolute difference 6.6%; 95% confidence interval (CI) = 6.5 to 6.8]. Duty increased from $0.2026 to $0.2622 per cigarette over the same period. In the adjusted model, a 1-cent increase in the duty component of price was not associated with changes in prevalence (0.019; 95% CI = -0.035 to 0.028). Increased non-duty component of price was associated with a decline in prevalence (-0.027; 95% CI = -0.052 to -0.002). This effect was stronger when changes in income were controlled for. CONCLUSIONS: In line with expectations, inflation-adjusted duty was not associated with changes in smoking prevalence, but it may have prevented upward pressure on prevalence that increasing affordability could have exerted. Frequent increases in duty greater than the growth in both wages and goods would more effectively reduce smoking than regular indexation. IMPLICATIONS: Few countries inflation-adjusted excise duty to ensure that tobacco products do not become more affordable; however, Australia experienced a decade of inflation adjustment alone, enabling the impact of this policy to be studied. This study shows that inflation-adjusted duty likely did prevent tobacco becoming more affordable and that indexation was associated with declines in smoking when tobacco companies over-shifted the duty rises (ie, increased price over and above duty rises).The study also suggests that frequent increases in taxation that exceed both wage growth and increases in costliness of other goods are needed to prompt increased rates of quitting.