Hospital-treated dog bite injury in Victoria
July 1998 to June 2004

Melinda Congiu, Erin Cassell, Karen Ashby

Summary

Hospital Admissions

For the six-year period, July 1998 to June 2004 there were 2,618 hospital admissions for dog bite injuries. Table 1 shows the annual frequency of these hospital admissions. Note that for the period July 1998 to June 2002, the coding did not distinguish between injuries caused by dog bites, and injuries caused by ‘other contact’ with dogs. This changed with the upgrade in the ICD-AM coding system in July 2002. It is estimated that annually approximately 44 cases over the period July 1998 to June 2002 were caused by ‘other contact’ with dogs and not dog bites.

Table 1 Frequency of dog bite hospital admissions, Victoria July 1998 to June 2004 (n=2,618)

*Includes cases of ‘other contact’ with dog
Source: Victorian Admitted Episodes Dataset (VAED) July 1998 to June 2004.

Figure 1 shows the trend in dog-bite hospitalisation rates per 100,000 population. Whilst there have been small year-to-year fluctuations, the trend line has no discernible slope.

Figure 1 Trends in hospital admission rates per 100,000 population for dog bite injuries, Victoria July 1998 to June 2004 (n=2,618)
Source: Victorian Admitted Episodes Dataset (VAED) July 1998 to June 2004.

Figure 2 Hospital admission rates per 100,000 population for dog bite injuries by age group, Victoria July 2003 to June 2004 (n 456)
Source: Victorian Admitted Episodes Dataset (VAED) July 1998 to June 2004.

Figure 2 shows the hospitalisation rates per 100,000 population for dog bite injuries by age group for the latest year of available data. The youngest and oldest age groups remain the most vulnerable to serious dog bite injuries.

The body region most commonly injured was the head, face and neck (43%, n=1,114), followed by the upper extremity (n=961, 37%,), particularly the wrist and hand (n=701, 27%). For child admissions, the body site most commonly bitten was the head, face and neck (0-4 years 87%; 5-9 years 77%; 10-14 years 61%). Among adults, the most frequent bite site was the upper extremity (15-69 years, 53%; 70 years and older 50%).

Emergency department presentations (non-admissions only)

Emergency department data was taken from the Victorian Emergency Department Minimum Dataset (VEMD). The VEMD collects data from public hospitals with 24 hour emergency services. One hundred percent state wide coverage applies from January 2004. Cases subsequently admitted to hospital were excluded from further analyses to avoid double counting with the VAED admissions data.

There were 7,573 non-admitted emergency department (ED) presentations for dog bite injuries identified on the VEMD over the six-year period July 1998 to June 2004.

Table 2 shows the frequency and percent of hospital emergency presentations by year of presentation. Although there appears to be an increase in the number of cases, this is most likely due to improvements in data quality and the increase in the number of hospitals contributing data.

Table 2 Dog bite hospital emergency department frequency data, Victoria
July 1998 to June 2004 (n=7,573)

*Eight additional hospitals began contributing to the dataset from January 2004 (n=252)

Figure 3 shows the number of people presenting to hospital for a dog bite injury by 4-year age groups. The 0-4 year age group has the highest proportion of cases, with the number of ED presentations decreasing with age.

Figure 3 Dog bite ED presentations (non-admissions) by age group, Victoria
July 1998 to June 2004 (n=7,573)
Source: Victorian Emergency Minimum Dataset (VEMD) July 1998 to June 2004

The body region most commonly injured was the upper extremity (46%) followed by the lower extremity (23%). Children aged 0-4 years were more likely to have suffered an injury to the head, face or neck (66%) compared to older children (5-9 years, 44% and 10-14 years 29%) and adults (15-69 years, 11%; 70 years plus, 3%). Adults were more likely to have an injury to the upper extremity (15-69 years, 54%; 70 years plus, 65%) than children (0-4 years, 21; 5-9 years, 26% and 10-14 years 33%).

The most common location for dog bite injury was the home (n=4,269, 56%), particularly so for the 0-4 year age group (n = 663, 74%). Twenty percent of dog bites injuries occurred in public places, and the location of the injury was unspecified in 14% of cases (Table 3).

Table 3 Dog bite ED presentations (non-admissions) by age and location,
Victoria July 1998 to June 2004 (n = 7,570)

Source: Victorian Emergency Minimum Dataset (VEMD) July 1998 to June 2004