Assessing quality gaps in hypertensive disorders of pregnancy care in China: an unannounced standardised patient study protocol.

backgroundImproving the quality of outpatient obstetric care is essential for achieving better maternal and perinatal outcomes, especially in resource-constrained settings. Despite guideline recommendations, substantial gaps remain in the delivery of evidence-based services and patient-centred care during routine antenatal encounters. Unannounced standardised patient (USP) methodology provides a robust and reproducible approach to objectively measure clinical performance. However, its large-scale application and value for multidimensional service quality assessment in obstetric outpatient settings remain underexplored, especially in low-income and middle-income countries (LMICs). METHODS AND ANALYSIS: We present a protocol that uses USPs to evaluate the quality and efficiency of outpatient obstetric care delivery. The study will be conducted across six cities in China's Hebei, Shanxi and Yunnan provinces. Trained USPs will conduct a total of 108 clinical visits from October to December 2025, with a projected study end date of December 2026. Primary outcomes will encompass two core dimensions: (1) technical capabilities, assessed through four metrics-(a) completeness of key history-taking items (continuous, 0-1 scale), (b) adherence to essential testing protocols (continuous, 0-1 scale), (c) diagnostic accuracy (ordinal: 0=incorrect, 1=partially correct, 2=correct) and (d) therapeutic appropriateness (ordinal: 0=incorrect, 1=partially correct, 2=correct); and (2) patient-centred care, quantified using the validated Chinese version of the Revised Patient Perception of Patient-Centeredness scale (PPPC-R; continuous, range 1-4, lower scores indicating more patient-centred care). USPs will receive comprehensive training to guarantee strict protocol adherence and consistent case presentation across all study sites. We will use OLS regression for continuous outcomes and logistic regression for binary outcomes to assess differences in case management across provider levels and USP-scenario interactions, controlling for city indicators. Logistic regression will also examine links between provider characteristics and quality outcomes, adjusting for city and USP dummies. This study is reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines (online supplemental file 3). ETHICS AND DISSEMINATION: Ethical approval has been granted by the ethics committee of Peking University Health Science Center Institutional Review Board (IRB00001052-24044). The results from this study will be actively disseminated through manuscript publications and conference presentations. PROTOCOL REGISTRATION NUMBER: Chinese Clinical Trial Registry (ChiCTR2500106140).