Identifying implementation barriers and facilitators of the chlamydia prevention and control project in Guangdong, China: a qualitative analysis using CFIR

Chlamydia trachomatis (CT) infection remains an important public-health and reproductive-health challenge in China. Guangdong Province launched the province-led “3331 Strategy” to integrate CT prevention with reproductive health, maternal and child health, and other sexually transmitted infection services; strengthen surveillance, testing, diagnosis, treatment, and case-management systems; expand testing among priority populations; and standardize the pathway from health promotion and screening to treatment, reporting, and follow-up. This study examined how the strategy was implemented across municipal health systems with different levels of early implementation performance. We conducted a post-implementation interpretive qualitative evaluation using a comparative case approach guided by the 2022 updated Consolidated Framework for Implementation Research (CFIR). All five existing municipal pilot implementation units were included as information-rich cases. Semi-structured telephone interviews were conducted with 60 administrative, public-health, programme-management, clinical, laboratory, nursing, and frontline service-delivery stakeholders. Two analytic streams were developed independently: a CFIR determinant-assessment stream based on coding, unit-construct evidence pools, case memos, and consensus ratings; and an implementation-performance stream based on project indicators, implementation records, programme documents, field-assessment notes, and expert-informed comparison. The streams were brought together only for cross-case interpretation. The cross-case joint display identified four explanatory patterns. First, Innovation Complexity interacted with local absorptive capacity: prior CT screening experience, workflow familiarity, laboratory capacity, and coordination routines helped the higher-implementation unit manage the multistep pathway, whereas lower-implementation units experienced target-population classification, questionnaire completion, specimen labelling and transfer, result feedback, and follow-up as cumulative burdens. Second, privacy-sensitive engagement was constrained by STI-related stigma, concern about disclosure, sensitive questionnaire items, and low public awareness. Third, leadership support, perceived need, and frontline commitment created a mandate to implement but were insufficient without practical workflow tools, site-specific training, material resources, and accountable coordination. Fourth, pandemic-related disruption and other contextual constraints were buffered or amplified by local adaptation, team organization, resource fit, and execution capacity. Province-led CT control requires both a clearly specified provincial core and implementation support that enables local systems to absorb operational demands. Refinement of the 3331 Strategy should simplify patient-facing procedures, strengthen confidential and non-stigmatizing communication, expand site-specific training, clarify laboratory and inter-institutional responsibilities, and permit feasible local adaptation. Separating determinant assessment from performance classification, and then integrating them through a cross-case joint display, provides a transparent basis for interpretation and programme action. Not applicable.