Sharing anonymized hospital data prevents violence, UK study finds

The World Health Organisation (WHO) has identified interpersonal violence as a global public health issue. In 2008-9, police recorded over 900,000 violent incidents in England and Wales, yet a substantial proportion of violence which results in treatment by doctors is not known to the police.

Targeted police work prevents violence, but depends on knowledge of when and precisely where violence occurs. So a team led by Professor Jonathan Shepherd at Cardiff University set out to investigate whether using information about the precise location and times of injury, derived from injured patients, can prevent more violence than police effort alone.

They analysed the impact of the Cardiff Violence Prevention Programme (CVPP), a data-sharing strategy for violence prevention implemented in Cardiff in 2001.

Anonymised data on precise violence location, time, days and weapons used, derived from patients treated for violent injury at hospital emergency departments, were shared over 51 months with police and local authority partners and used to target resources for violence prevention.

Results were compared with 14 similar cities in England and Wales without the intervention.

Information sharing and use of this information to target violence 'hot spots' was associated with a significant (42%) reduction in violence-related hospital admissions relative to the comparison cities. In Cardiff, rates fell from seven to five a month per 100,000 people compared with an increase from five to eight in comparison cities.

There was also a significant increase in minor assaults (those not resulting in injuries) recorded by the police, from 15 to 20 a month per 100,000 people in Cardiff compared with a decrease from 42 to 33 in comparison cities, suggesting that more accurate targeting led to faster and more frequent police intervention.

This data sharing model is currently being implemented in the UK (there is a coalition government commitment to information sharing by hospitals in England for violence prevention) and is advocated by WHO, say the authors.

"Our findings suggest that communities can achieve substantial reductions in the public health burden of violence through organised data driven partnerships between health, law enforcement agencies, and local government," they conclude.

Furthermore, it is likely that the main conclusions of this study are applicable outside the UK, they add.

In an accompanying editorial, Alexander Butchart from WHO, says he hopes the Cardiff model will be emulated by other cities in developing and developed countries. He concludes that, if subsequent studies also find the significant reductions in violence shown in Cardiff, "it would increase confidence in the value of this new tool to prevent violence."