Examination of public health data shines a welcome light on which communities suffer the least – and most – violence, explains Ian Warren.

People living in ethnically diverse neighbourhoods are less likely to suffer an assault than are residents of areas with little or no racial diversity. This is one of the striking results of analysis of public health data in Greater Manchester.

The data confirms that residents in the poorest neighbourhoods are substantially more likely to attend hospitals’ A&E departments – or be admitted to hospital for continuing treatment – because of an assault than are people living in more affluent areas.

However, the presence of ethnic diversity reduces the impact of poverty on levels of violence. This suggests that poor white neighbourhoods suffer higher levels of violence than do poor but ethnically diverse neighbourhoods – a pattern supported by other data.

Residents of fast changing neighbourhoods are also more likely to attend hospital because of assault – especially those areas with large numbers of students. But the phenomenon is not restricted to student areas.

There is a strong relationship between the impact of violence on a neighbourhood and its closeness to on-licence and off-licence alcohol outlets.

Areas with a high density of off-licence alcohol retailers – including supermarkets, as well as specialist off-licences – suffer a greater amount of serious violence resulting in hospital admissions. This finding confirms research elsewhere that ‘pre-loading’ with alcohol before a night out is likely to lead to more serious intoxication and thus more serious violence.

Public health data provides both a more comprehensive and a more reliable picture of the impact of violence on local communities than do official crime statistics. It is not possible to rely on official crime statistics to provide a rounded picture of the impact of violence. In January the UK Statistics Authority stripped the police of their national statistics status, amid concerns that officers were ‘manipulating’ the numbers.

Those of us who research interpersonal violence have known for many years that police-recorded crime statistics are a poor means to measure the scale of violence. Most violence is never reported to, or recorded by, the police. Victims may fear reprisals from their attacker if they involve the police, particularly in cases of domestic violence.

And there may be hostility towards the police, translating into an unwillingness to involve them. In some cases, the victim may not believe a crime has taken place, or that little is to be gained from reporting the incident.

Even in that minority of cases which are reported, statistics provide little indication of what has happened. A police officer exercises his or her judgement in deciding whether the reported act conforms to a number of criteria laid down in the official counting rules drawn up by the Home Office. Has a crime been committed? Is there evidence to the contrary? Does the victim believe a crime has been committed? Does the victim have the requisite determination to give evidence? How serious is the crime?

The combination of these various factors inevitably leads to under-reporting and under-recording of violent crime. This is frustrating for criminologists, but now we know we have a new, exciting and reliable data source: public health data.

While most violent incidents go unreported and unrecorded, the majority of victims seek medical treatment for their injuries. Typically this is through an attendance at A&E, although ambulance services are also called out to treat victims of violence. Both A&E departments and ambulance services explicitly record those incidents that are the result of an assault.

The use of public health data is not brand new: successive governments have recognised their role in complementing or improving police-recorded crime statistics, particularly related to interpersonal violence.

Dr Jonathan Shepherd and colleagues at the Violence and Society Research Group in Cardiff, and the Trauma and Injury Intelligence Group in Liverpool, have both demonstrated the potency of this data. Like any data source, there are limitations, mostly concerning the recording practices of hospitals and the challenge of ensuring patient anonymity.

One of the constraints in the use of traditional sources of information is the lack of linkage. Offender A is taken away to the police station, while Victim B carries themselves off to the hospital for treatment. The police – hopefully – record the crime and the hospital treats the victim. But we are unable to connect the data.

So public health data, if integrated with police data, has the potential to truly enrich our understanding of the dynamics of interpersonal violence. I hope to see a system develop where police and public health professionals use the same identifiers and technology to record not just assaults, but a wide range of incidents that require police and health interventions.

This would enable researchers to begin to tell the story behind violent assaults; assaults which can have such a devastating effect on people’s lives.

In my opinion, public health data is of such importance that its use will become increasingly common and provide substantial new insights into the tragedy of interpersonal violence.

• The research has drawn on public health data from the North West Ambulance Service and from hospital admissions across Greater Manchester.