The number of young women driving under the influence of alcohol and involved in fatal car crashes is increasing, indicates research published in Injury Prevention.
In 2007 alone, alcohol related fatal car crashes accounted for almost a third of the total in the US.
The research team analysed data from the US National Highway Traffic Safety Administration on fatal road traffic collisions for the years 1995 to 2007 inclusive.
They looked at the proportion of drivers whose blood samples had contained alcohol across five age bands: 16; 17; 18; 19 to 20; and 21 to 24 years.
Blood alcohol levels were categorised as 0.01 to 0.07 g/dl, which is below the legal drink drive limit in the US; 0.08 to 0.14g/dl, which is at or above the legal drink drive limit; and 0.15 and above, at which level a driver has a 100-fold increased risk of a collision.
In all, there were just short of 180,000 fatal car crashes among drivers aged 16 to 24 during the study period.
Rates among young men fell year on year by 2.5 crashes per 100,000 of the population. They fell in all four age groups up to the age of 20 and remained the same for those aged 21 to 24 between 1995 to 2007.
The rates among young women were much lower than those of their male peers in each of the years studied, but they did not follow the same patterns.
Among 16 year old women drivers, the rate fell by 0.8 per 100,000 of the population and remained the same for 17 and 18 year olds. And it increased by 0.7 per 100,000 of the population among 19 year olds and by 0.6 per 100,000 for those aged 21 to 24.
The increase in the proportion of young female drivers with a positive blood alcohol test involved in a fatal collision was also greater (3.1%) than it was for young male drivers (1.2%).
The highest increase in fatal collisions was among drivers with a blood alcohol of 0.15g/dl or higher. This rose 2% among women compared with 2.4% among young men.
But the increase in the proportion of young drivers involved in fatal crashes with positive blood alcohol tests at all times of the week was greater among young women than it was among young men.
This rose by 3.5% on weekdays and 2.2% at weekends among young women compared with 1.5% and 0.4%, respectively, among young men.
The authors point out that the gender patterns evident in this study mirror increasing trends in drug misuse among young women, possibly as a result of changing social and cultural norms.