Table 1
Response rates by age and method of recruitment
| 18–22 years No (%) | 23–27 years No (%) | 28–32 years No (%) | Total No (%) | |
|---|---|---|---|---|
| Group 1 Mail and telephone: | ||||
| Number | 26 (100) | 21 (100) | 18 (100) | 65 (100) |
| Agreed to participate | 14 (54) | 14 (67) | 7 (39) | 35 (54) |
| Urine provided | 10 (38) | 12 (57) | 7 (39) | 29 (45) |
| Group 2 Mail: | ||||
| Number | 16 (100) | 26 (100) | 27 (100) | 69 (100) |
| Agreed to participate | 2 (13) | 6 (23) | 8 (30) | 16 (23) |
| Urine provided | 2 (13) | 5 (19) | 7 (26) | 14 (20) |
| Total | 12 (29) | 17 (36) | 14 (31) | 43 (32) |
