TABLE 4.
Baseline characteristics of national health and nutrition examination survey (NHANES) participants between 2001 and 2004 after propensity score matching (PSM).
| Characteristic | Non-ED | ED | p |
| Total patients | 896 | 896 | |
| Age (years), n (%) | 0.864 | ||
| < 40 years | 76 (4.2%) | 73 (4.1%) | |
| ≥ 40 years | 820 (45.8%) | 823 (45.9%) | |
| Race, n (%) | 0.005 | ||
| Mexican American | 160 (8.9%) | 155 (8.6%) | |
| Other hispanic | 26 (1.5%) | 32 (1.8%) | |
| Non-hispanic white | 529 (29.5%) | 584 (32.6%) | |
| Non-hispanic black | 161 (9%) | 106 (5.9%) | |
| Other race–including multi-racial | 20 (1.1%) | 19 (1.1%) | |
| Education level, n (%) | 0.171 | ||
| Less than high school | 302 (16.9%) | 315 (17.6%) | |
| High school diploma | 215 (12%) | 182 (10.2%) | |
| More than high school | 379 (21.1%) | 399 (22.3%) | |
| Marital status, n (%) | 1.000 | ||
| Married | 625 (34.9%) | 624 (34.8%) | |
| Unmarried | 271 (15.1%) | 272 (15.2%) | |
| Annual household income, n (%) |
0.482 | ||
| Over $20,000 | 659 (36.8%) | 673 (37.6%) | |
| Under $20,000 | 237 (13.2%) | 223 (12.4%) | |
| BMI (kg/m2), n (%) | 1.000 | ||
| < 25.0 | 236 (13.2%) | 237 (13.2%) | |
| ≥ 25.0 | 660 (36.8%) | 659 (36.8%) | |
| Hypertension, n (%) | 0.297 | ||
| Yes | 428 (23.9%) | 405 (22.6%) | |
| No | 468 (26.1%) | 491 (27.4%) | |
| Current health status, n (%) | 0.418 | ||
| Excellent, very good, good | 673 (37.6%) | 657 (36.7%) | |
| Fair or poor | 223 (12.4%) | 239 (13.3%) | |
| Diabetes, n (%) | 0.017 | ||
| Yes | 115 (6.4%) | 140 (7.8%) | |
| No | 774 (43.2%) | 738 (41.2%) | |
| Borderline | 7 (0.4%) | 18 (1%) | |
| Magnesium (mg), median (IQR) | 280 (202, 393.25) | 260 (191, 338.25) | < 0.001 |
| Zinc (mg), median (IQR) | 11.41 (7.55, 16.5) | 10.34 (7.06, 14.74) | 0.002 |
| Copper (mg), median (IQR) | 1.25 (0.88, 1.72) | 1.11 (0.84, 1.5) | < 0.001 |
| Selenium (mcg), median (IQR) | 108 (78.15, 147.25) | 98.4 (71.68, 130.75) | < 0.001 |
For categorical variables, P values were analyzed by chi-square tests. For continuous variables, P values were analyzed by Wilcoxon rank sum test. BMI, body mass index; PSM, propensity score matching. IQR, interquartile range.