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Sex and age distribution of participants
| Characteristics | Male* | Age (years)Δ |
| Control (n=619) | 356 (57.5) | 51.14±11.92 |
| SMS (n=615) | 360 (58.5) | 50.01±10.99 |
| Telephone (n=614) | 348 (56.7) | 50.52±11.53 |
The data shown as number (%); significant difference: χ 2=0.023, P=0.989;
Significant difference: F=0.770, P=0.463
