Perils of police action: a cautionary tale from US data sets.

OBJECTIVE: To count and characterise injuries resulting from legal intervention by US law enforcement personnel and injury ratios per 10 000 arrests or police stops, thus expanding discussion of excessive force by police beyond fatalities.

DESIGN: Ecological.

POPULATION: Those injured during US legal police intervention as recorded in 2012 Vital Statistics mortality census, 2012 Healthcare Cost and Utilization Project nationwide inpatient and emergency department samples, and two 2015 newspaper censuses of deaths.

EXPOSURE: 2012 and 2014 arrests from Federal Bureau of Investigation data adjusted for non-reporting jurisdictions; street stops and traffic stops that involved vehicle or occupant searches, without arrest, from the 2011 Police Public Contact Survey (PPCS), with the percentage breakdown by race computed from pooled 2005, 2008 and 2011 PPCS surveys due to small case counts.

RESULTS: US police killed or injured an estimated 55 400 people in 2012 (95% CI 47 050 to 63 740 for cases coded as police involved). Blacks, Native Americans and Hispanics had higher stop/arrest rates per 10 000 population than white non-Hispanics and Asians. On average, an estimated 1 in 291 stops/arrests resulted in hospital-treated injury or death of a suspect or bystander. Ratios of admitted and fatal injury due to legal police intervention per 10 000 stops/arrests did not differ significantly between racial/ethnic groups. Ratios rose with age, and were higher for men than women.

CONCLUSIONS: Healthcare administrative data sets can inform public debate about injuries resulting from legal police intervention. Excess per capita death rates among blacks and youth at police hands are reflections of excess exposure. International Classification of Diseases legal intervention coding needs revision.