VIOLENT DEATHS IN SA The 2003 National Injury Mortality Surveillance System

The latest data from the National Injury Mortality Surveillance System – the most detailed source on the ‘who, what, when, where and how’ of fatal injuries in South Africa – shows that homicide remains the most common cause of injury-related deaths. Homicide rates varied significantly between the four major urban centres covered, and firearms were a key contributor to the high homicide rates. Alcohol was confirmed as an important risk factor for murder, with the highest percentage of alcohol positive cases being recorded in Cape Town.

A study based on mortality data from 2000 estimated that there were more than 32,000 homicides in South Africa -a mortality rate of 72 per 100,000 population. 1 Although this study probably overestimated homicide by approximately 7%, 2 the data still imply a mortality rate due to violence that is nearly eight times the global rate of 8.8 deaths per 100,000 population. 3though more recent data from the South African Police Service suggest that homicide rates may have decreased, 4 the 2003 National Injury Mortality Surveillance System (NIMSS) annual report indicates that homicide remains the most common cause of injury-related deaths. 5This means that South Africa still has some way to go before our rates of violence begin to approach those experienced elsewhere in the world.This article describes selected findings and interpretations from the most recent NIMSS data pertaining to homicide. 6

Background to the NIMSS
The NIMSS has provided information about the extent and scope of deaths due to non-natural causes in South Africa since 1999.It is the most detailed source of information on the who, what, when, where and how of fatal injuries in South Africa and has secured full coverage of five of the country's six metropolitan centres as well as several other major towns and cities.
Data are collected at state mortuaries by the police and forensic pathology departments.The cause of death is categorised according to the International Classification of Disease version 9 (ICD 9) to enable international comparisons.Spatial and temporal data are recorded as well as blood alcohol data from state forensic chemical laboratories.
Although studies have used the NIMSS data as a basis for extrapolation to national estimates, the data set is more reflective of urban rather than rural injury patterns in South Africa.In 2003, 36 mortuaries in seven of South Africa's nine provinces supplied data to the NIMSS (Table 1).This represents between 36-49% of all injury-related deaths that occur in South Africa. 7chard Matzopoulos MRC-UNISA Crime, Violence and Injury Lead Programme richard.matzopoulos@mrc.ac.za

VIOLENT DEATHS IN SA The 2003 National Injury Mortality Surveillance System
The latest data from the National Injury Mortality Surveillance System -the most detailed source on the 'who, what, when, where and how' of fatal injuries in South Africa -shows that homicide remains the most common cause of injury-related deaths.Homicide rates varied significantly between the four major urban centres covered, and firearms were a key contributor to the high homicide rates.Alcohol was confirmed as an important risk factor for murder, with the highest percentage of alcohol positive cases being recorded in Cape Town.The aim is ultimately to establish a permanent system that will record all such deaths that occur annually in South Africa in order to provide information to: • describe the incidence, causes and consequences of non-natural deaths;

Mortuary
• prioritise injury and violence prevention action directed at high-risk groups and socioenvironmental risk factors; • identify new injury trends and emerging problem areas; • monitor seasonal and longitudinal changes in the non-natural fatality profile; and • evaluate direct and indirect violence and injury prevention and control measures.

Distribution of homicide in 2003
In 2003 10,499 (47%) of the 22,248 non-natural deaths in the NIMSS where the apparent manner (or intention) of death was known, were homicides (Figure 1).Homicides accounted for a significantly higher percentage of non-natural deaths (p<0.01) in Cape Town (55%) and Durban (54%) than in Johannesburg (47%) and Pretoria/Tshwane (31%).
Among the major cities with full coverage, the highest mortality rate was recorded in Cape Town, where there were 66 homicides per 100,000 population, compared to 61 per 100,000 in Durban, 52 per 100,000 in Johannesburg and 24 per 100,000 in Pretoria/Tshwane (Figure 2).
For the sample as a whole, the cause of death was unknown in only 70 of these homicides.Of the remaining deaths, the leading cause was gunshot injuries (Figure 3), which accounted for 52%, followed by sharp force injuries (31%), blunt force injuries (14%) and strangulation (2%).
Among the major cities, the leading causes of death were firearms, followed by sharp force injuries (e.g.stabbing), blunt force injuries and strangulation.However, there were relatively more sharp force fatalities in Cape Town, compared to Durban and Johannesburg where the rates for firearm homicide were higher.

Firearms
Firearms were the leading external cause of homicides across all age groups from the age of five years.Of the 6,167 firearm deaths recorded by the NIMSS in 2003, 87% were violence-related and the rest were mainly suicide-related, except for 20 unintentional deaths (less than 1%).Gunshot injuries accounted for 53% of male and 41% of female homicides.The 46 recorded firearm deaths among children aged 0-14 years in Cape Town, Durban, Johannesburg and Pretoria/Tshwane were all violence-related except for one unintentional injury death in Johannesburg.

Male and female homicide
Males were disproportionately affected by fatal violence with 6.5 male homicides recorded for every female homicide.Although male homicides are more common than female homicides internationally, the ratio recorded by the NIMSS was approximately double that of the world average of 3.2 male homicides for every female homicide. 8 The male to female ratio was highest in Cape Town (8.5:1), followed by Durban (7.5:1), Johannesburg (7.2:1) and Pretoria/Tshwane (5.1:1) (Table 2).Cape Town had the highest rate of fatal violence among females (7.7 per 100,000 population), followed by Johannesburg, Durban and Pretoria/Tshwane at 7.6, 7.3 and 4.5 per 100,000 of the population respectively.
Although men are at greater risk of being murdered, the majority of perpetrators for both male and female deaths are male.A recent MRC study found that in 2001, approximately half of all women murdered were killed by an intimate partner 9 and there are several allusions to this in the NIMSS data.Males outnumbered females for most causes of homicide in the NIMSS data set, with the exception of deaths due to strangulation.Furthermore, a far higher percentage of women were killed in private homes than men (42% versus 32%).

Age of victims
Analysis of homicide by age reveals that the number of homicides increased dramatically from the age of 15 to 44 years, with the highest number of homicides recorded in the 25-29 age group (Figure 4).In 2003, homicide was the leading manner of non-natural death for all ages from 15 to 45 years and violencerelated gunshot injuries are the single largest cause of injury death for all ages from 15 to 60 years.Surprisingly, homicide rates among South African children were no higher than the world average in most age groups.The exception was among girls younger than four years where homicide rates were approximately 60% higher than the world average. 10

Temporality of homicide
The most common days for homicide were Saturdays followed by Sundays in all four major cities, although the weekend peak was most noticeable in Cape Town, where nearly half of all homicides (49%) occurred on these two days.Overall, more violent deaths occurred between 20h00 and 23h00 (27%) than any other three-hour period, and again this evening peak was apparent in all four cities.
In the four major cities, homicide peaked in Cape Town between January and March; in Johannesburg between February and April, in Pretoria/Tshwane from October to December and in Durban between March and May (Figure 5).

Alcohol
More than half of homicide victims tested positive for alcohol, with the highest percentage of alcohol  positive cases being recorded in Cape Town (53%), followed by Pretoria/Tshwane (49%), Johannesburg (46%) and Durban (44%).The levels of intoxication in Cape Town were also significantly higher than in Johannesburg (p<0.01) and Durban (p<0.01).
Victims of sharp force homicide had the highest percentage of alcohol-positive cases (72%) as well as the highest mean blood alcohol concentration among the alcohol positive cases (0.19g/100ml).
In summary, the analysis of the NIMSS data indicated that homicide rates are much higher in South Africa than in the rest of the world and that there is also considerable variation in homicide rates between different urban centres.Firearms were a major contributor to the high homicide rates in all of the cities included in the NIMSS, and future analysis will provide pointers as to whether the new Firearms Control Act will have been successful in reducing firearm violence.
The data also clearly showed that males are at greater risk of being murdered than females, particularly those in the 15-44 year age group.The NIMSS results also confirmed that alcohol was an important risk factor, and it should be noted that other studies have shown a link between alcohol dependence and child abuse, 11 while excessive drinking by men is significantly associated with partner violence across different settings. 12These factors, as well as the weekend and evening peaks have important implications for law enforcement and violence prevention.

Are rates of violence decreasing?
The 2003 NIMSS data established both the substantial prevalence and magnitude of homicide in South Africa's four largest metropolitan cities.  homicides since 1993. 13The release of 2004 homicide data by SAPS in September 2005 provided further evidence of a decreasing trend. 14 is, however, worth questioning the utility of comparing the NIMSS data with that of the SAPS.
Although the police's crime data potentially offers a richer pool of information, as there is not only a larger number of cases, but also the potential for more event-specific descriptive variables, these databases need to be underpinned by reliable reporting of non-natural deaths.South Africa's strict death registration system, which specifies that all non-natural deaths be subject to a post-mortem investigation, lends itself to a robust and accurate surveillance system.This is particularly true in urban areas, where it is more difficult for bodies to be disposed of outside the system.

Table 2 :
Mortality rates per 100,000 population in South Africa's four largest cities in 2003

Table 3 :
Homicide in South Africa's four largest cities from 2001 to 2003 The utility of the information collected by the NIMSS lies in the pointers it provides for improving the prevention and control of injuries in South Africa, and in evaluating the impact of direct (e.g.gun law enforcement) and indirect (e.g.socioeconomic development) interventions that are expected to reduce some of the major causes of fatal injury.At the city level, the NIMSS and other sources of crime, violence and injury data can be used to inform violence and injury prevention initiatives through the various phases of formulation, implementation and evaluation.Utility may be enhanced by linking various systems such as death registration and SAPS crime analysis data, and interagency collaboration is one of the measures proposed by the Medical Research Council-UNISA Crime, Violence and Injury Lead Programme that will enable enhanced city safety between now and 2010.Others include systematic reviews of existing injury prevention strategies and the development of city-level policies for injury and violence prevention and safety promotion.