Incidence of Dog Bite-Associated
Emergency Department Visits in
Maryland, 2008-2012
Financial and Policy Implications
Emily Pieracci, DVM, MPH Candidate
Project Introduction & Overview
• 4.7 million dog bites occur every year
• 1 million of which are in children under 18 years of age
• IR in children is 129.3 per 100,000 persons
• Highest injury rates are observed in children 5-9 years of age
• Males are disproportionately represented among dog bite victims
• Over 53% of males accounting for all injuries
• Dog bites can be psychologically traumatizing, disfiguring,
incapacitating, and even fatal
Project Introduction & Overview
• Incidence of dog bites has been associated
with the age of the patient
• Younger children bitten due to unintentionally
provocative behavior
• Children are shorter in stature
• Parents or dog owners may have limited
supervision of children while they are interacting
with dogs
Financial Costs
• An estimated annual medical cost of over $100 million for dog biterelated emergency services in the U.S
• Estimated mean medical cost >$630 for ED visits per individual
between 2008-2010
Methods- Health Service Cost Review Commission (HSCRC)
• The non-confidential outpatient HSCRC dataset for the years 20082012 was searched for emergency room visits for dog biteassociated injuries.
• The HSCRC diagnoses are recorded using International
Classification of Diseases, Ninth Revision, Clinical Modification
(ICD-9-CM) codes.
Methods- ICD-9-CM
• Official system of assigning codes to diagnoses and procedures
associated with hospital utilization in the United States.
• Categorized
• primary diagnostic codes
• with additional external cause of injury codes (E codes) being assigned as needed.
• The code E906.0 is specifically used to denote dog bite-related
injuries
Methods-Patients
• Cross-sectional study
• All patients that were seen in an emergency room in a Maryland
healthcare facility during 2008-2012
• All records with
• E906.0 and
• Emergency room charges greater than $0
• Maryland census data from 2010 and population estimates from
the U.S. Census Bureau were used for analyzing data.
Annual Trends
Incidence Rate of ER Visit due to Dog Bite Injuries by
Year
• Linear regression
analyses
96.00
Incidence Rate
• 2008 was the
baseline year for
analysis
98.00
94.00
92.00
90.00
88.00
86.00
84.00
2008
2009
2010
Year
2011
2012
Incidence Rates of Dog Bite Injuries in Maryland by Year
Year
Frequency
Maryland
Incidence per 100,000
Population
2008
5,470
5,684,965
96.2
2009
5,388
5,730,388
94.0
2010
5,087
5,773,552
88.1
2011
5,500
5,839,572
94.1
2012
5,240
5,884,563
89.0
Total
26,685
5 year average
92.4
Incidence rates of Dog Bite Injuries; Descriptive Analysis
ED Visits
2008-2012
Maryland Population 2010
Average Annual Incidence Rate per
100,000
Sex
Male
Female
Age Category
0-4
5 to 9
10 to 14
15-19
20-24
25-29
30-34
35-44
45-54
55-64
65-84
85+
13,775
12,910
2,791,762
2,981,790
98.7
86.6
2,759
3,116
2,588
2,068
2,269
2,031
1,610
3,107
3,281
2,024
1,644
188
364,488
366,686
379,029
406,241
393,698
393,548
368,494
795,572
902,204
695,768
609,516
98,126
151.4
170.0
136.6
101.8
115.3
103.2
87.4
78.1
72.7
58.2
53.9
38.3
Incidence rates of Dog Bite Injuries; Descriptive Analysis
ED Visits
2008-2012
Maryland Population 2010
Average Annual Incidence Rate per
100,000
Race
White
Black /African
American
Asian/Pacific Islander
Am. Indian, Eskimo
Other
Biracial
Unknown
Ethnicity
Hispanic
Not Hispanic
Unknown
Total
17,583
6,930
3,359,284
1,700,298
104.7
81.5
483
75
1,336
205
73
322,010
20,420
206,832
164,708
30.0
73.5
129.2
24.9
1,044
22,216
3,425
26,685
470,632
5,302,920
44.4
83.8
5,773,552
92.4
Sex of Dog Bite Victims in Maryland, 2008-2012
Male
48%
52%
Female
Incidence Rates of Dog Bites by Age Category
170.0
151.4
Incidence Rates
136.6
115.3
103.2
101.8
87.4
78.1
72.7
58.2
53.9
38.3
Under 5
5-9
10-14
15-19
20-24
25-29 30-34
Age Group
35-44
45-54
55-64
65-84
85+
5 Year Frequency and Average Annual Incidence Rates by County:
County
Average County
Population 20082012
Number of ED Visits Average Annual ED
2008-2012
Visit IR
Number of Aggregate
Reports 2008-2012
Average Annual
Aggregate IR
Allegany County
74,665
536
143.57
730
195.58
Anne Arundel County
538,132
2024
75.22
4318
160.35
Baltimore City
620,642
4046
130.38
4238
136.57
Baltimore County
807,069
3306
81.93
4639
115.14
Calvert County
88,732
586
132.08
1028
231.51
Caroline County
32,947
178
108.05
335
203.36
Carroll County
167,225
731
87.43
1261
150.81
Cecil County
101,096
804
159.06
1019
201.56
Charles County
146,994
608
82.72
1118
152.14
Dorchester County
32,562
429
263.50
598
234.65
Frederick County
234,101
1042
89.02
1301
110.69
Garrett County
30,083
205
136.29
301
200.01
5 Year Frequency and Average Annual Incidence Rates by County
County
Average County
Population 20082012
Number of ED Visits Average Annual ED
2008-2012
Visit IR
Number of Aggregate
Reports 2008-2012
Average Annual
Aggregate IR
Harford County
245,313
1057
86.18
1961
159.87
Howard County
288,372
948
65.75
1297
89.73
Kent County
20,187
170
168.43
154
152.53
Montgomery County
973,978
2695
55.34
2717
55.75
Prince George's
County
864,986
2687
62.13
2738
63.28
Queen Anne's
County
47,878
231
96.50
555
231.60
St. Mary's County
105,403
673
127.70
894
169.28
Somerset County
26,398
118
89.40
189
143.12
Talbot County
37,731
191
101.24
254
134.67
Washington County
147,811
750
101.48
1067
144.28
Wicomico County
98,905
611
123.55
1195
241.76
Worcester County
51379.00
369
143.64
668
259.92
Aggregate Bite Reports vs. Emergency Room Visits
• Statewide more aggregate bite reports than ER visits
• 33% more aggregate bite reports than ER visit reports
• Maryland aggregate bite report system is working effectively at county level
Total Charges Associated with Dog Bite Injuries by Year
Year
Minimum
Charge
Maximum
Charge
Median
Charge
Total Annual
Charges
2008
$22.00
$10,210.38
$265.14
$2,150,000.00
2009
$28.39
$11,278.01
$283.76
$2,430,000.00
2010
$26.02
$13,849.05
$294.53
$2,650,000.00
2011
$7.00
$18,226.87
$297.62
$3,250,000.00
2012
$25.50
$47,880.86
$325.16
$3,740,000.00
Limitations and Challenges
• Medical record review not performed to verify E-coding, chief complaints, or
triage notes.
• Includes only patients seen in MD
• Don’t capture MD residents bitten and treated in other jurisdictions
• No reference group
• No control group, everyone in dataset was a dog bite victim
• Is the population being treated for dog bites in the ER different from the rest of the
population seen in the ER?
• Coding error with county variables
• Slowed data analysis
• Had to recode and re-run analysis
Lessons Learned
• Be flexible
• Sometimes you have to go back to drawing board
• Collaboration is the key
• Get to know people who work in areas that you are less knowledgeable in
• Ask your colleagues for help
• Recognize your limitations
• There’s always another analysis you can run—know when to stop
Policy Implications
• Breed Specific Legislation are laws that regulate dog ownership based
on the breed of the dog
• Advocates claim it reduces the number of attacks resulting in severe
injuries to people
• Opponents state that there is little evidence that such laws actually
reduce the number of dog bites
Source: www.animallaw.info/topics/tabbed
Policy Implications
• Annual trends for 2008-2012 don’t support change in incidence of
dog bite injuries
• May need to follow for longer time
• Focus on targeting interventions toward high risk groups
• Children
• Dog Owners
Practice Implications
• Interventions should be aimed at high risk
groups
• Children in pre-school
• Children 5-9 years old in elementary school
• Consideration for spring/summer programs
when interactions with dogs may be higher
References
• Overall, K. L., & Love, M. (2001). Dog bites to humans- demography, epidemiology, injury and risk. Journal of the American Veterinary
Medical Association, 1923-1934.
• Maryland Health Services Cost Review Commission. (2013, November 15). Retrieved from Maryland Health Services Cost Review
Commission Website: www.hscrc.state.md.us/
• ICD-9-CM. (2013, November 15). Retrieved from Centers for Disease Control and Prevention: http://www.cdc.gov/nchs/icd/icd9cm.htm
• V-Codes and E-Codes FAQ. (2013, November 15). Retrieved from American College of Emergency Physicians:
http://www.acep.org/Clinical---Practice-Management/V-and-E-Codes-FAQ/
• REFERENCE DROPPPING $0 ER CHARGES- EMAIL FROM ANDREA, HSCRC ADDENDUM
• 2010 Census Interactive Population Search. (2014, March 28). http://www.census.gov/2010census/popmap/ipmtext.php?fl=24
• Maryland Statistical Handbook.. (4 April, 2014). Retrieved from Department of Planning, Maryland State Data Center Website:
http://planning.maryland.gov/msdc/md_statistical_handbook11.pdf, page 4.
• By County Order (2012). (4, April 2014). Retrieved from Department of Planning, Maryland State Data Center Website:
http://planning.maryland.gov/msdc/Pop_estimate/Estimate_12/municipal/popest_muni12.shtml
• Age Profile 1: Age by Sex for Persons in Households and Persons in Group Quarters (2010). (15, April 2014). Retrieved from
Department of Planning, Maryland State data Center Website:
http://planning.maryland.gov/msdc/census/cen2010/SF1/AgeProf/age_MDST.pdf, page 1 & 2.
• American Veterinary Medical Association: Task Force n Canine Aggression and Human-Canine Interactions (2001). A Community
Approach to Dog Bite Prevention. Journal of the American Veterinary Medical Association, 218; 11; 1732-1749.
• Protect Maryland Dogs, Accessed November 20,2013. www.humanesociety.org/animals/dogs/protect_maryland_dogs.html
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Acknowledgements
• Dr. Katherine Feldman, DHMH
• Ms. Kimberly Mitchell, DHMH
• Ms. Brenna Hogan, DHMH
• Ms. Mary Armolt, DHMH
• Dr. Meghan Davis, JHU