Evolving determinants of implementing low-risk childbirth quality improvement in Japan: a longitudinal qualitative study

BACKGROUND: International evidence suggests that reducing user costs increases maternity care utilization but not necessarily care quality, underscoring the need for transparent, comparable measurement. In Japan, evidence-based maternity care for low-risk childbirth has not been systematically evaluated, and limited claims-data capture hinders assessment, benchmarking, and sustained quality improvement. We aimed to explore how determinants (facilitators and barriers) of implementing a multifaceted quality improvement intervention for low-risk childbirth emerge and evolve over time. METHODS: This longitudinal qualitative study was performed at four facilities in the Kinki region of Japan using a process-evaluation approach. The intervention included quarterly performance-based audits and feedback to healthcare providers caring for low-risk women, multidisciplinary team-based quality improvement efforts, and educational sessions addressing care quality and organizational culture. Healthcare providers involved with low-risk childbirth participated in semi-structured interviews at the beginning and end of the intervention. Data were analyzed using directed content analysis, following the Consolidated Framework for Implementation Research (CFIR), to identify facilitators and barriers of the intervention, observe changes over time, and compare variations across facilities. Ethical approval was obtained from the Ethics Committee of Kyoto University (R2342 and R2344), and all interview participants provided written informed consent. RESULTS: Across 66 semi-structured interviews with 41 participants, four CFIR constructs-Champions, Key Stakeholders, Structural Characteristics, and Networks and Communications-transitioned from serving as facilitators to barriers during the intervention. In contrast, the Knowledge and Beliefs about the Intervention construct remained stable within each facility over time, although its valence differed across facilities. Facilities where Champions exhibited participatory leadership and effectively disseminated the intervention's positive value experienced greater stakeholder engagement and smoother implementation. In contrast, in facilities where the intervention was perceived as having low value, various context-driven factors hindered implementation. CONCLUSIONS: The role-related CFIR constructs, such as Champions and Key Stakeholders, exhibited more dynamic change over time, whereas perceptions of the intervention's value remained relatively constant. Consistently positive perceptions of value facilitated sustained participation despite the presence of additional barriers. These findings highlight temporal fluctuations in implementation determinants and underscore the importance of supporting key roles and offering phase-specific, contextually responsive implementation support over time.