Contact patterns and times for cohort follow-up study
| Follow-up | Cell phone call | Short text message | QQ/MSN | Peer contact | Landline telephone | Total | |
|---|---|---|---|---|---|---|---|
| 6 months | 884 | 1075 | 665 | 87 | 31 | 5 | 2747 |
| 12months | 908 | 1104 | 704 | 93 | 43 | 2 | 2854 |
| Total (%) | 1792 (32.0) | 2179 (38.9) | 1369 (24.4) | 180 (3.2) | 74 (1.3) | 7 (0.1) | 5601 (100.0) |
QQ, Tencent QQ; MSN, Mobile Social Network.