Table 1. Characteristics of cases and controls.
| Variable | Case(n=499) | Control(n=500) | P |
|---|---|---|---|
| Sex | < 0.001 | ||
| Male | 263 (52.7) | 192 (38.4) | |
| Female | 236 (47.3) | 308 (61.6) | |
| Age | < 0.001 | ||
| yr (mean ± SD) | 36.7±13.3 | 50.4±7.8 |
P < 0.05 indicates statistical significance.
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