Table 2.
Characteristics of cases and controls, and number of visits to the emergency department, univariate odds ratio (OR), 95% confidence intervals, and p-values
| Cases (n = 152) | Controls (n = 1520) | |||
|---|---|---|---|---|
| N (%) | N (%) | OR (95% CI) | p-value | |
| Age | ||||
| Mean (standard deviation) | 42 (15) | 43 (18) | 1.00 (0.99-1.01) | 0.79 |
| Median, IQR (Lower, Higher) | 43 (29, 53) | 39 (27, 56) | ||
| Gender | ||||
| Male | 103 (68) | 817 (54) | 1.00 Referent | |
| Female | 49 (32) | 703 (46) | 0.55 (0.39-0.79) | 0.001 |
| Number of visits | ||||
| 1 | 49 (32) | 869 (57) | 1.00 Referent | |
| 2 | 21 (14) | 335 (22) | 1.11 (0.66-1.88) | 0.69 |
| 3 | 22 (14) | 163 (11) | 2.39 (1.41-4.07) | 0.001 |
| 4 | 18 (12) | 71 (5) | 4.50 (2.49-8.13) | <0.001 |
| 5 | 6 (4) | 28 (2) | 3.80 (1.50-9.61) | 0.005 |
| 6 | 7 (5) | 20 (1) | 6.21 (2.51-15.38) | <0.001 |
| 7 | 7 (5) | 12 (1) | 10.35 (3.90-27.44) | <0.001 |
| 8 | 6 (4) | 3 (0) | 35.47 (8.61-146.08) | <0.001 |
| 9 | 3 (2) | 3 (0) | 17.74 (3.49-90.15) | 0.001 |
| 10 or more | 13 (9) | 16 (1) | 14.41 (6.56-31.64) | <0.001 |