Table 3. Comparisons of County Characteristics by Outlier Status (No Outlier, Low Outlier, High Outlier).
| Characteristica | Firearm death | Firearm homicide | Firearm suicide | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean (SD) | Mean (SD) | Mean (SD) | ||||||||||
| No outlier (n = 3029) | Low outlier (n = 15) | High outlier (n = 67) | P valueb | No outlier (n = 3034) | Low outlier (n = 14) | High outlier (n = 63) | P valueb | No outlier (n = 3046) | Low outlier (n = 12) | High outlier (n = 53) | P valueb | |
| Geography | ||||||||||||
| RUCC | 5.05 (2.66) | 8.67 (0.49) | 7.01 (2.67) | <.001 | 5.10 (2.67) | 6.71 (3.02) | 5.11 (3.02) | .079 | 5.04 (2.66) | 8.83 (0.39) | 8.13 (1.53) | <.001 |
| Land area, square miles | 944.76 (1300.86) | 959.18 (512.58) | 1334.57 (1488.67) | <.001 | 957.17 (1314.71) | 1002.42 (1019.95) | 751.95 (639.92) | .7 | 940.55 (1292.12) | 1101.69 (555.57) | 1647.50 (1810.42) | <.001 |
| Sociodemographic | ||||||||||||
| Sex ratio (M/F) | 0.99 (0.09) | 1.09 (0.18) | 0.99 (0.07) | .003 | 0.99 (0.09) | 1.01 (0.11) | 0.94 (0.07) | <.001 | 0.99 (0.09) | 1.03 (0.11) | 1.01 (0.05) | <.001 |
| Aged 15-65 y, % | 66.07 (3.26) | 65.17 (4.65) | 64.30 (3.72) | <.001 | 66.05 (3.30) | 66.44 (2.30) | 64.79 (2.59) | .023 | 66.06 (3.25) | 64.44 (4.91) | 64.25 (4.14) | <.001 |
| Black, % | 9.03 (14.30) | 2.51 (4.99) | 11.67 (25.17) | <.001 | 8.44 (13.57) | 23.88 (25.54) | 35.48 (27.47) | <.001 | 9.23 (14.69) | 1.22 (3.38) | 0.64 (1.33) | <.001 |
| Hispanic, % | 7.09 (12.56) | 5.41 (6.93) | 8.55 (13.61) | .6 | 7.12 (12.55) | 11.74 (20.83) | 5.64 (10.20) | .5 | 7.07 (12.56) | 4.67 (7.04) | 9.73 (13.11) | .3 |
| Education | ||||||||||||
| High school graduate, % | 83.04 (7.33) | 84.90 (5.42) | 84.10 (8.08) | .3 | 83.18 (7.30) | 75.96 (7.49) | 79.45 (7.45) | <.001 | 83.01 (7.34) | 85.75 (5.16) | 86.26 (7.13) | .002 |
| Economic | ||||||||||||
| Median household income, $ | 39 209.42 (10 066.57) | 33 630.47 (5484.75) | 33 683.72 (7317.72) | <.001 | 39 258.12 (10 039.63) | 31 921.36 (7169.45) | 31 278.94 (5987.54) | <.001 | 39 168.94 (10 069.29) | 33 035.00 (7003.28) | 34 369.85 (6701.12) | <.001 |
| Unemployment rate, %c | 5.37 (1.73) | 4.89 (2.36) | 5.70 (2.44) | .2 | 5.34 (1.72) | 6.56 (2.82) | 6.86 (2.44) | <.001 | 5.38 (1.74) | 5.29 (2.34) | 5.12 (2.42) | .06 |
| Poverty, % | 15.33 (6.50) | 16.00 (4.05) | 17.60 (7.87) | .10 | 15.20 (6.38) | 21.64 (8.80) | 22.83 (8.08) | <.001 | 15.36 (6.51) | 18.58 (10.82) | 15.83 (6.11) | .4 |
| Politics | ||||||||||||
| Republican voters, % | 60.18 (12.35) | 68.60 (14.42) | 61.56 (19.61) | .01 | 60.48 (12.31) | 55.82 (20.80) | 50.08 (17.63) | <.001 | 60.04 (12.46) | 66.68 (15.35) | 70.55 (13.48) | <.001 |
| Health | ||||||||||||
| Heavy drinkers, % | 13.15 (2.28) | 14.81 (4.42) | 14.16 (3.70) | .11 | 13.17 (2.34) | 14.25 (1.72) | 13.21 (2.17) | .079 | 13.15 (2.26) | 16.62 (5.99) | 14.35 (4.07) | .045 |
| Trauma care accessd | 26.47 (43.67) | 2.33 (2.87) | 7.69 (11.28) | <.001 | 1.45 (2.87) | 0.64 (1.65) | 0.94 (1.27) | .092 | 1.46 (2.87) | 0.00 (0.00) | 0.25 (0.73) | <.001 |
| Firearm dealers | ||||||||||||
| Firearm licensese | 1.46 (2.87) | 0.13 (0.35) | 0.58 (1.18) | <.001 | 26.05 (43.39) | 4.57 (3.55) | 26.54 (40.04) | <.001 | 26.42 (43.59) | 3.17 (3.30) | 4.98 (4.18) | <.001 |
Abbreviation: RUCC, rural-urban continuum code.
See eTable 1 in the Supplement for details on county characteristics. Timings of measures range from 1999 to 2010, with most characteristics measured in 2005.
Group comparisons across the 3 groups (no outlier, low outlier, high outlier) were performed using Kruskal-Wallis rank sum test. All P values were adjusted for multiple testing by using the Benjamini-Hochberg method to control for the false discovery rate. See eTable 9 in the Supplement for posthoc pairwise comparisons.
Refers to the number unemployed as a percentage of the labor force (eTable 1 in the Supplement).
Refers to number of level I trauma centers within 60 miles (direct distance).
Per capita prevalence of type 1 (firearm dealer) and type 2 (pawnbroker) federal firearm licenses.