Table 1.
Study characteristics
| Feature | Trials, no. (%) | Participants, no. | Urban participants, no. (%) |
Rural participants, no. (%) |
P value a |
|---|---|---|---|---|---|
| Location | |||||
| Arizona | 90 (31) | 266 | 240 (90) | 26 (10) | <0.0001 |
| Florida | 77 (26) | 384 | 313 (81) | 71 (18) | |
| Midwest | 212 (73) | 1663 | 1029 (62) | 634 (38) | |
| Type of study risk(s) | |||||
| Minimal risk | 7 (2) | 285 | 191 (67) | 94 (33) | 0.6 |
| Greater than minimal risk | 285 (98) | 2028 | 1391 (69) | 637 (31) | |
| Study risks | |||||
| Blood draws | 265 (91) | 1779 | 1222 (69) | 557 (31) | 0.6 |
| Use of drugs or biological agents | 250 (86) | 1576 | 1091 (69) | 485 (31) | 0.2 |
| Use of drugs or biological agents requiring FDA review | 43 (15) | 269 | 182 (68) | 87 (32) | 0.8 |
| Use of medical or educational records | 209 (72) | 1676 | 1144 (68) | 532 (32) | 0.8 |
| Use of ionizing radiation | 152 (52) | 949 | 672 (71) | 277 (29) | 0.04 |
| Any invasive procedure(s) | 145 (50) | 1029 | 715 (69) | 314 (31) | 0.3 |
| Use of medical devices | 55 (20) | 735 | 483 (66) | 252 (34) | 0.06 |
| Use of medical devices that require FDA review | 16 (5.5) | 125 | 74 (59) | 51 (41) | 0.02 |
| Use of recombinant DNA or human gene transfer | 3 (1) | 13 | 8 (62) | 5 (38) | 0.6 |
| Infectious agents | 2 (0.7) | 4 | 2 (50) | 2 (50) | 0.4 |
| Human stem cells, human embryos, or their derivatives | 1 (0.3) | 1 | 1 (100) | 0 (0) | 0.5 |
| Remuneration | 221 (76) | 1518 | 1052 (69) | 466 (31) | 0.2 |
FDA, US Food and Drug Administration.
a
χ2 test comparing the proportion of rural versus urban clinical trial participants by location, type of study risk(s), study risks, and remuneration.