The pilot used a stepped wedge design over three phases from Aug 1, 2013, to Sept 30, 2014. Chlamydia testing and diagnosis rates in the control (pretraining) and intervention (post-training) periods were compared by use of a multivariable negative binomial regression model with general practice fitted as a random effect. Owing to the stepped wedge design, the number of months contributing to the control and intervention periods differed depending on which phase the general practice was allocated to and when the practice received training. Characteristics of general practices participating were included in the model. Practices were not paid for the intervention. The Research Governance Coordinator for Public Health England confirmed that no ethics approvals were needed for this study.
The 460 participating practices conducted 26 021 tests in the control period and 18 797 tests during the intervention period. Intention-to-treat analysis showed decreased median number of tests and diagnoses per month per practice after receiving training (2·68 tests before training [IQR 1·00–4·77] vs 2·67 after training [1·10–4·90]; 0·14 diagnoses before training [0–0·30] vs 0·13 after training [0–0·27]). Adjusted multivariable regression analysis showed no significant change in overall testing or diagnoses (incidence rate ratio [IRR] 1·01, 95% CI 0·96–1·07 and 0·98, 0·84–1·15, respectively). Testing increased significantly in 148 practices where payment was already in place before the intervention (IRR 2·12, 95% CI 1·41–3·18).
This large national pilot found that educational support sessions to increase chlamydia screening in primary care were only effective in practices that already receive payment for chlamydia screening. 3Cs & HIV training might be a useful way to make better use of the resources already available. However this intervention will not increase national testing rates substantially. Although increases found in subgroups were statistically significant, they were still relatively small in magnitude.
The 3Cs & HIV pilot was funded by Public Health England and was part of the Chlamydia Testing Training in Europe (CATTE) project. CATTE is part funded by a Leonardo Transfer of Innovation grant as part of European Union Lifelong Learning Programme.