Tailoring implementation strategies to promote brief verbal intervention for smoking cessation among primary healthcare providers: a hybrid III multi-center randomized factorial trial

Background The current situation regarding tobacco consumption in China is grave, posing a significant threat to the health of smokers. The Chinese government has implemented several policies aimed at controlling tobacco use. Brief verbal Intervention for Smoking Cessation (BISC) has been demonstrated as highly effective and cost-efficient. Primary Healthcare (PHC) providers play a pivotal role as pioneers in executing BISC. However, the current execution of BISC within PHC providers in China falls short of ideal standards. Thus, this study aims to devise more suitable implementation strategies to facilitate the implementation of BISC by PHC providers in China. Method This study will utilize the Multiphase Optimization Strategy (MOST) to conduct two-phase randomized trial in Guangdong, Hubei and Xinjiang in China. In the preparation phase, a scoping review will be conducted to examine current findings on the facilitators and barriers of BISC implementation by PHC providers, employing the Consolidated Framework for Implementation Research (CFIR). Expert Recommendations for Implementing Change compilation (ERIC) will inform the development of primary implementation techniques. Following an online survey utilizing best-worst scaling (BWS) to rank the most effective implementation techniques, stakeholder discussions will be conducted to create a list of candidate implementation techniques and their respective levels, as well as to identify optimization objectives. Subsequently, in the optimization phase, a factorial trial involving more than 152 participants will be conducted to ascertain the optimized combination of implementation techniques, which will then be validated in the evaluation phase. The study outcomes align with the principles of Proctor's Implementation Outcomes Framework (IOF) and RE-AIM. Primary (delivery of BISC), secondary (coverage of BISC delivery), and other outcomes (applicability, acceptance, and costs of BISC delivery) will be collected through Unannounced Standardized Patient (USP) visits, semi-structured interviews, NPT-guided questionnaires, and administrative data. Modified Poisson Regression Models (MPRM) will be employed to test hypotheses concerning the main effects of the implementation techniques and their interaction effects on the primary outcome of the study. Discussion This protocol outlines the utilization of the MOST framework to customize the optimized combination of implementation techniques for BISC within the local context. Trial registration Chinese Clinical Trial Registry ChiCTR2300069008. Registered on August 19, 2022.