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) | ||
---|---|---|---|
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 |
Maleb | 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 |
Blackb | 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 assistanceb | 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 unemployedb | 0.88 (0.72-1.08) | 0.952 (0.787-1.141) | 0.90 (0.77-1.06) |
Households with female heads of houseb | 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 diplomab | 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
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.
For each 10% of population.