Bilardi et al. BMC Public Health 2010, 10:70 http://www.biomedcentral.com/1471-2458/10/70 Page 4 of 9 Trial registration This study was registered on the Australian New Zeal- and Clinical Trial Registry, registration number ACTRN12608000499381. Results Intervention and control groups A total of 145 practices were approached to participate in the trial - 26 were ineligible to participate, 107 declined and 12 consented to participate (Figure 1). The first practice was recruited on 12th May 2008, with the final practice completing the 6 month trial on the 3rd January 2009. Twenty five GPs in the control group and 20 in the intervention group consented to the study. During the trial period, two GPs from one practice (control group) withdrew. Table 1 outlines the demographic characteristics of participating GPs. Groups were comparable with the exception that control group GPs were more likely to be younger (under 45 years) and have a post-graduate qualification. Proportion of patients tested In the 12 month pre-trial period, 6.2% (95% CI: 4.2, 8.4) of women in the control group were tested for Metropolitan practices N=8 0 practices 2 GPs withdrew Six months later N=6 practices included 23 GPs involved 144 clinics contacted 109 practices not interested 23 practices ineligible 12 practices enrolled (45 GPs) [randomly allocated by geographic and socio-economic stratum] Randomisation Rural practices N=4 Contr ol 6 practices (25 GPs) not offered $5 per chlamydia test with 16-24 year olds Inter vention 6 practices (20 GPs) offered $5 per chlamydia test with 16-24 year olds 0 practices withdrew Six months later N=6 practices included 20 GPs involved Figure 1 Flow of participating practices through the trial. The following figure provides the flow of participating general practices through the trial.