Table 1. Assessment of Non-Response Bias.
| Respondents | Non-Respondents | P value† | |
|---|---|---|---|
| Full sample | 1,212 (3.7%) | 31,332 (96.3%) | |
| Years licensed*, median (IQR) | 14.6 (5.6-23.0) | 11.8 (3.9-20.5) | <0.0001 |
| 0-10 | 474 (39.4%) | 14,921 (48.0%) | |
| 11-20 | 360 (29.9%) | 8,997 (28.9%) | |
| 21+ | 369 (30.7%) | 7,814 (23.1%) | |
| Florida | 331 (3.3%) | 9,663 (96.7%) | |
| Years licensed*, median (IQR) | 15.7 (5.1-22.3) | 11.8 (4.0-20.0) | 0.0002 |
| 0-10 | 118 (36.2%) | 4,564 (48.0%) | |
| 11-20 | 114 (35.0%) | 2,950 (31.0%) | |
| 21+ | 94 (28.8%) | 2,002 (21.0%) | |
| New Jersey | 202 (4.4%) | 4,407 (95.6%) | |
| Years licensed*, median (IQR) | 15.9 (9.3-25.6) | 13.4 (7.5-21.1) | 0.0017 |
| 0-10 | 63 (31.7%) | 1,670 (38.5%) | |
| 11-20 | 65 (32.7%) | 1,584 (36.5%) | |
| 21+ | 71 (35.7%) | 1,088 (25.1%) | |
| Ohio | 304 (3.7%) | 7,823 (96.3%) | |
| Years licensed*, median (IQR) | 14.6 (6.7-24.5) | 13.1 (5.0-21.6) | 0.0332 |
| 0-10 | 114 (37.5%) | 3,346 (42.8%) | |
| 11-20 | 95 (31.3%) | 2,436 (31.1%) | |
| 21+ | 95 (31.3%) | 2,041 (26.1%) | |
| Texas | 347 (3.7%) | 9,092 (96.3%) | |
| Years licensed*, median (IQR) | 12.1 (2.7-22.6) | 8.1 (2.0-19.6) | 0.0002 |
| 0-10 | 165 (47.7%) | 5,169 (57.0%) | |
| 11-20 | 77 (22.3%) | 1,902 (21.0%) | |
| 21+ | 104 (30.1%) | 1,995 (22.0%) | |
| Wyoming | 28 (7.5%) | 347 (92.5%) | |
| Years licensed*, median (IQR) | 10.2 (3.5-19.8) | 9.2 (3.6-17.8) | 0.6578 |
| 0-10 | 14 (50.0%) | 190 (54.8%) | |
| 11-20 | 9 (32.1%) | 110 (31.7%) | |
| 21+ | 5 (17.9%) | 47 (13.5%) |
Values are n (%) unless otherwise noted. Bolded percentages are calculated by row. Non-bolded percentages are calculated by column. Some percentages are based on a lower denominator due to missing data for years licensed. IQR, Interquartile range
*
Calculated using initial license date from state board and survey deployment date
†
P values are from Mann-Whitney U tests comparing years licensed between respondents and non-respondents