| Intervention (2 blocks) | Control (2 blocks) | |||
| Flats | People | Flats | People | |
| Total | 36 | 36 | ||
| Unable to contact occupants | 4 | 4 | ||
| Did not wish to participate | 3 | 9 | ||
| Started in study | 29 | 42 | 23 | 26 |
| Completed study | 19 | 27 | 7 | 9 |
| Withdrawn because of youth | – | 3 | – | – |
| Moved house during study | 7 | 9 | 10 | 10 |
| Withdrew from study | 3 | 3 | 6 | 7 |