Introduction Provision of sexual health services in primary care is necessary to reduce STIs, such as chlamydia. We piloted an educational training programme, based on the theory of planned behaviour, for general practice staff with the aim of increasing chlamydia and HIV testing, and provision of condoms and contraceptive information (3Cs and HIV).

Methods The pilot was delivered with a step wedge design over three phases. Chlamydia testing and diagnosis rates pre and post-training were compared separately for men and women using a multivariable negative binomial regression model with general practice fitted as a random effect. Month of test and practice population size were adjusted for and an interaction between the intervention and area of implementation fitted.

Results 460 general practices agreed to participate in the pilot. These conducted 2448 tests across the pre and post intervention period. Intention to treat analysis showed decreased median test and diagnoses per month post-intervention (2.68 vs 2.67; 0.14 vs 0.13 respectively). The multivariable regression analysis did not find a significant change in testing or diagnoses of men. There was a significant increase in testing (IRR 1.15 CI 1.01–1.31) of women but no change in diagnoses (IRR 0.98 CI 0.84–1.18). Interaction between the intervention and area of implementation was found in both testing rate models for women.

Conclusion This large national pilot found that educational support sessions slightly increased chlamydia testing in women within general practices after they received the 3Cs and HIV training but not diagnoses. The area of implementation had an impact on the programme’s effect, so further exploration of the factors that contribute to this increase is required.

Disclosure of interest statement Public Health England is funded by the UK Department of Health.