Table 1.
Study population characteristics
| No (%) participants | |||
| Characteristic | HIE cases (n=15 798) | No-HIE controls (n=15 798) | p Value |
| Site of care | 1* | ||
| Direct access site 1 | 30 (0.2%) | 30 (0.2%) | |
| Direct access site 2 | 6 (0%) | 6 (0%) | |
| Direct access site 3 | 3 (0%) | 3 (0%) | |
| Direct access site 4 | 189 (1.2%) | 189 (1.2%) | |
| Direct access site 5 | 46 (0.3%) | 46 (0.3%) | |
| Direct access site 6 | 187 (1.2%) | 187 (1.2%) | |
| Direct access site 7 | 184 (1.2%) | 184 (1.2%) | |
| Direct access site 8 | 446 (2.8%) | 446 (2.8%) | |
| Direct access site 9 | 982 (6.2%) | 982 (6.2%) | |
| Direct access site 10 | 1718 (10.9%) | 1718 (10.9%) | |
| Direct access site 11 | 1228 (7.8%) | 1228 (7.8%) | |
| Total direct access group | 5019 (31.8%) | 5019 (31.8%) | |
| Mixed access site | 10 779 (68.2%) | 10 779 (68.2%) | |
| Average age (years) | 40.4±22.7 | 40.4±22.7 | 0.925† |
| Gender | 1* | ||
| Female | 10 281 (65.1%) | 10 281 (65.1%) | |
| Male | 5517 (34.9%) | 5517 (34.9%) | |
| Race | 1* | ||
| Black | 9267 (58.7%) | 9267 (58.7%) | |
| Caucasian | 6280 (39.8%) | 6280 (39.8%) | |
| Other/not specified | 251 (1.6%) | 251 (1.6%) | |
| Insurance coverage | 1* | ||
| Commercial (BC) | 3755 (23.8%) | 3751 (23.8%) | |
| Medicare | 3874 (24.5%) | 3874 (24.5%) | |
| Medicaid (TN) | 5324 (33.7%) | 5327 (33.7%) | |
| Self-pay/indigent | 2482 (15.7%) | 2483 (15.7%) | |
| All other | 363 (2.3%) | 363 (2.3%) | |
| Other characteristics‡ | |||
| Charlson index§ | 1.93±4.41 | 1.65±4.20 | <0.001† |
*
Pearson's χ2 test.
†
Wilcoxon test.
‡
Variable included in regression models but not in case–control matching.
§
Mean±SD.
HIE, health information exchange.