South West Public Health Observatory Trends in patients admitted to hospital whose admission involves an assault using a knife or other sharp instrument, England, 1997 to 2005 Roy Maxwell, Caroline Trotter, Julia Verne, Paul Brown, David Gunnell

South West Public Health Observatory Background to the study Knife attack on Law Society man BBC News, Tuesday 24 th Jan 2006 Paramedic needed counselling after knife ordeal, court told Paramedic UK, August 2004 Did you witness assault on bus in Warlingham? Surrey Police, August 2006

South West Public Health Observatory Not just pen-knives Source: Edinburgh News 4 th July 2006

South West Public Health Observatory Not just knives Source: Lifestyle News 1 st January 2006 Later in the night, a 17- year-old youth was stabbed no less than seven times, apparently with a broken beer bottle, outside a West End nightclub. He too was rushed to hospital. This man was one of London’s New Year Eve’s 35 stabbing victims.

South West Public Health Observatory Existing Home Office statistics for assaults involving a knife Statistics on crime can be complex and difficult to compare meaningfully Police ‘recorded’ and ‘reported’ crimes British Crime Survey (BCS) – ‘Gold standard’ but known to under-report certain forms of violent crime (only 47,000 people approximately in survey)

South West Public Health Observatory British Crime Survey for England and Wales Violent crime fell by 43% between 1995 (4.26m) and 2004/5 (2.42m), principally due to large falls in domestic and acquaintance violence Violent assaults by strangers declined in absolute numbers, but increased as a proportion of all violent crime 170,000 fewer violent incidents involving the use of a knife in 2005/6 than in 1995 (but 25,000 more in 2005/6 than 2004/5) Greater proportion of violent crime now takes place in the public arena i.e. ‘on the street’ Inference is that public concern over violent crime is largely due to increased visibility

South West Public Health Observatory What do comparative data tell us? Knife crime increased in Scotland – homicide rate rose by 83% between 1981 & 2003 and 47% of these crimes involved a knife A. Leyland, Journal Public Health, 2006 Research from Wales suggests that 50% of patients who present to hospital for an assault-related injury do not have their injuries reported to the police I. Sutherland, Injury Prevention, 2002

South West Public Health Observatory Overview Objective: identify trends in in-patient admissions in England for assaults that involve stabbing, & to augment existing statistics Design: analysis of trends over time using Hospital Episode Statistics (HES) Setting:England, 1 st April 1997 to 31 st March 2005 Outcome:completed hospital admissions with a mention of assault by sharp object (ICD-10 X99) Study size: 33,903 patients

South West Public Health Observatory Methods Data extracted 21 st February 2006 Directly age-standardised admission rates (ASARs) were calculated using ONS mid-year population estimates and the European Standard population Analyses performed using Stata Version 9.1 First admission only per patient was included patients with multiple admissions (n=806) had subsequent admissions excluded Patients with conflicting diagnoses excluded (n=98)

South West Public Health Observatory Main results Admissions increased 30% over study period, from 3,770 patients in 1997/8 to 4,891 patients in 2004/5 (13 per day): 70 admissions in 2004/5 were for children <15yrs Median length of stay in hospital was 1 day (IQR 0 to 3 days) 42% of admissions (n=14,220) occurred on either a Saturday or Sunday 24% of admissions (n=8,139) were for London GOR residents 154 patients died (in-hospital case fatality 0.5%): - 18% of the 874 stabbing assault deaths recorded by ONS - majority of deaths do not occur in hospital

South West Public Health Observatory Principal site of injury Site of injury% Deaths% No deaths Head, neck, thorax 6348 Abdomen, l / back, lumbar spine pelvis 2317 Shoulder, elbow, arm 110 Wrist & hand 115 Hip to foot 55 Other 84

South West Public Health Observatory Summary results for admissions by sex MalesFemales N 30,464 (90%)3,406 (10%) Median age 27yrs (IQR 21-35)29yrs (IQR 21-38) 15 to 44 yrs 27,128 (89%)2,790 (82%) Inj to head, neck, thorax 14,786 (49%)1,383 (41%) ASAR 100,000 in 1997/ (CI 13.0, 14.0)1.6 (CI 1.5, 1.8) ASAR 100,000 in 2004/ (CI 17.8, 18.9)1.9 (CI 1.7, 2.1)

South West Public Health Observatory Male age-specific admission rates (per 100,000) for injuries associated with stabbing from an assault, England, Source: Hospital Episode Statistics

South West Public Health Observatory Female age-specific admission rates (per 100,000) for injuries associated with stabbing from an assault, England, Source: Hospital Episode Statistics

South West Public Health Observatory Limitations ICD-10 coding does not permit detailed breakdown of the assault weapon Not possible to ascertain whether patient was the perpetrator or victim of assault Study does not include patients who: - received treatment other than as an in-patient - died before receiving treatment - did not have conclusive diagnosis of assault recorded Women less likely than men to have an assault diagnosis I. Sutherland, Injury Prevention, 2002

South West Public Health Observatory Discussion Admissions for assault by a sharp object increased by 30% between 1997/8 and 2004/5, and currently an average of 13 people per day are admitted to hospital. These figures do not fit comfortably with the suggestion that violent incidents involving a knife are decreasing These data, like other data sources, underestimate the magnitude of this type of assault, but when used in conjunction may substantially improve current estimates Accurate assessment of the scale of the problem is paramount to understanding the effect of particular measures such as knife amnesties

South West Public Health Observatory Acknowledgements The Hospital Episode Statistics were made available by the NHS Health and Social Care Information Centre.

South West Public Health Observatory Contact details Roy Maxwell ( University of Bristol & South West Public Health Observatory South West PHO Grosvenor House 149 Whiteladies Road Bristol BS4 2RA