Demographic tabulations
We tabulated data by victim age group, sex, race and Hispanic ethnicity, rurality, mechanism (eg, firearm), and, for hospital admissions, by alcohol and drug involvement of the person injured. All tables were run in SAS V.9.4., applying sample weights to the HCUP data, which are public use samples of approximately 20% of all US discharges.
Data deficits limited our analysis of race-ethnicity. NEDS cannot supply nationally representative race-ethnicity estimates because many states do not either identify race and ethnicity or collect emergency department (ED) data centrally. We therefore restricted the race-ethnicity analysis to fatal and hospital-admitted injuries.
Denominators
As denominators for producing injury ratios, we used the sum of FBI-tabulated arrest data, adjusted for non-reporting,
31 and 2011 PPCS-based national estimates (which we computed using STATA V.11) of police street stops without arrest and of traffic stops where a person or vehicle was searched but the person stopped was not arrested.
32 In 2012, FBI arrest data largely excluded Alabama, the District of Columbia, Hawaii, Illinois (except Chicago and Rockford) and New York City, and lacked demographic detail for Florida. Online search provided arrest data that we manually added for three of these jurisdictions: Hawaii,
33Alabama
34 and New York City.
35 ,
36 We adjusted the remaining FBI-reported data to US estimates under the assumption that arrest rates by region for the 82% of the US population covered by the FBI data and our supplements were representative of arrest rates in those regions in frequency and demographics. The FBI only began collecting Hispanic origin in 2013 arrest data, with reporting much more complete in 2014 than 2013. We supplemented the 2014 data
11 with a racial breakdown for New York City.
37 ,
38 Our analyses classified all minority Hispanics (eg, five of the deceased) by their minority race. We assumed white Hispanics would constitute the same 28.6% of arrested whites in 2012 as in 2014. Although we used 2011 stop counts, because 2011 PPCS data were sparse for some racial groups, we distributed them using an average percentage breakdown by race that we computed from pooled 2005, 2008 and 2011 surveys.
32 ,
39 To test significance of ratio differences, we computed pairwise bivariate CIs between related demographic categories (eg, male vs female).