Intervention schedules for stepped wedge design; ‘pre’ represents a pre-intervention survey and ‘post’ represents surveys occurring post-intervention
| Group | Survey/period of collection | |||
| 1 | 2 | 3 | 4 | |
| November to December 2006 | October to November 2007 | May to June 2008 | January to February 2009 | |
| 1 | Pre | Post | Post | Post |
| 2 | Pre | Pre | Post | Post |
| 3 | Pre | Pre | Pre | Post |