. 2018 Mar 5;178(5):692–700. doi: 10.1001/jamainternmed.2018.0190

Table 4. Multilevel Bayesian Conditional Autoregressive Poisson Models for Counts of Homicide by Firearms (January 2010-December 2014) for Counties (N = 3108) Nested Within Contiguous US States (N = 48).

Description	IRR (95% CI)
Description	Model 2A: Firearm Homicide	Model 2B: Nonfirearm Homicide	Model 2C: All Homicide
Firearm Policies
Low home state, low interstate	1.38 (1.02-1.88)^a	1.24 (0.99-1.57)	1.32 (1.03-1.67)^a
Low home state, medium interstate	1.33 (1.02-1.75)^a	1.29 (1.04-1.60)^a	1.28 (1.03-1.59)^a
Low home state, high interstate	1.18 (0.89-1.54)	0.97 (0.78-1.20)	1.07 (0.86-1.32)
Medium home state, low interstate	1.22 (0.88-1.70)	1.17 (0.90-1.53)	1.22 (1.00-1.49)
Medium home state, medium interstate	1.22 (0.95-1.56)	1.16 (0.95-1.41)	1.13 (1.01-1.27)
Medium home state, high interstate	1.15 (0.94-1.39)	1.09 (0.91-1.29)	1.13 (0.96-1.32)
High home state, low interstate	1.13 (0.84-1.53)	1.11 (0.84-1.45)	1.11 (0.95-1.29)
High home state, medium interstate	1.11 (0.74-1.65)	0.95 (0.64-1.39)	1.07 (0.78-1.48)
High home state, high interstate	1 [Reference]	1 [Reference]	1 [Reference]
Census Characteristics
Population (model offset)
Area (1000 sq miles)	1.03 (1.01-1.06)^a	1.35 (1.11-1.65)^a	1.04 (1.02-1.06)^a
Male^b	0.98 (0.96-1.00)^a	1.04 (1.02-1.05)^a	1.00 (0.99-1.01)
Median age (for each 10 y increase)	1.13 (1.04-1.24)^a	1.07 (1.01-1.13)^a	1.09 (1.03-1.16)^a
Black^b	1.20 (1.15-1.25)^a	0.98 (0.95-1.02)	1.12 (1.08-1.15)^a
Hispanic (for each 10% of population)	1.06 (1.01-1.11)^a	0.94 (0.91-0.97)^a	1.01 (0.98-1.04)
Median household income (for each additional $10 000)	0.94 (0.90-0.98)^a	0.97 (0.94-1.00)^a	0.95 (0.92-0.98)^a
Households receiving public assistance^b	1.75 (1.42-2.14)^a	1.34 (1.15-1.66)^a	1.66 (1.42-1.95)^a
Population aged ≥16 y who are unemployed^b	0.88 (0.72-1.08)	0.952 (0.787-1.141)	0.90 (0.77-1.06)
Households with female heads of house^b	1.29 (1.16-1.41)^a	1.57 (1.44-1.71)^a	1.41 (1.29-1.52)^a
Population aged ≥25 y without high school diploma^b	1.08 (1.00-1.18)^a	1.11 (1.04-1.19)^a	1.08 (1.02-1.15)^a
Crime
Property crimes (1 per 100 population)	1.04 (1.03-1.06)^a	1.03 (1.02-1.04)^a	1.04 (1.02-1.05)^a
Violent crimes (1 per 100 population)	1.15 (1.06-1.26)^a	1.14 (1.06-1.3)^a	1.15 (1.07-1.22)^a

Abbreviations: CI, credible interval; IRR, incidence rate ratio

^{^a}

Estimates have credible intervals that do not include an IRR of 1.0. Parameter estimates for county population constrained to an IRR of 1.0.

^{^b}

For each 10% of population.