Accelerated Partner Therapy: optimising an inter-actional contact tracing intervention to reduce chlamydia reinfection

Background: A number of interventions have evolved to assist with contact tracing for sexually transmitted infections (STIs) yet absence of theoretical support, detailed description and specific intervention components result in heterogeneous delivery with ambiguous outcomes. This paper reports a process to optimise Accelerated Partner Therapy (APT), a UK partner notification intervention, to reduce chlamydia reinfection.Method: Varied data sources involved an analysis of behavioural elements of existing contact tracing interventions identified through systematic review, a behavioural analysis of videos of APT, a behaviourally informed analysis of qualitative data from 56 patients/public, 30 healthcare professionals (HCPs) and expert input including the use of the APEASE criteria in specifying content for the intervention manual. This involved the theoretical domains framework (TDF), the Behaviour Change Wheel (BCW) and the Behaviour Change Technique Taxonomy (BCTT) to specify potentially useful ways of optimising APT that would enhance engagementResults: The APT intervention was characterised as interactional; involving HCPs, index patients and sex partners. It involved four main delivery steps and eight behavioural domains. Varied barriers and facilitators to engagement with APT were identified and further analysed to optimise APT content. The APEASE criteria were used to select and prioritise content/intervention functions for inclusion in the intervention manual, training materials and all information material to support the delivery of APT for HCP and index patients (videos, leaflets etc.) Discussion The approach outlined here aimed to behaviourally inform APT in order to provide a transparent way of optimising the intervention by specifying its active components and theorising its key mechanisms. We include a supplementary file with the final intervention manual.