| Characteristics | Total | Any TTI | P-value |
| Total | 1586 | 13 (0.81) |
|
Gender | Male | 972 | 9 (0.93) | 0.555 |
| Female | 614 | 4 (0.65) |
|
Age groups in years (n = 1585) | 16 - 30 | 1124 | 6 (0.53) | 0.014 |
| 31 - 45 | 305 | 7 (2.30) |
|
| 46 - 59 | 126 | 0 |
|
| >60 | 30 | 0 |
|
NBSZ branch | Harare | 685 | 5 (0.73) | 0.524 |
| Bulawayo | 293 | 2 (0.68) |
|
| Gweru | 222 | 4 (1.80) |
|
| Masvingo | 201 | 1 (0.54) |
|
| Mutare | 185 | 1 (0.50) |
|
Marital Status. | Married | 284 | 5 (1.80) | 0.132 |
| Not married | 787 | 4 (0.51) |
|
| Not recorded | 515 | 4 (0.78) |
|
Occupation | Students | 783 | 3 (0.38) | 0.212 |
| Professionals | 245 | 4 (1.63) |
|
| Others | 63 | 1 (1.59) |
|
| Not recorded | 495 | 5 (1.01) |
|
Donor Status | First time | 232 | 11 (4.74) | <0.001 |
| Repeat | 1354 | 2 (0.15) |
|