Medical Sociology of Antenatal Care Visit Sequencing and Emergency Obstetric Referral Initiation in Rural Malawian Health Centres: A Sequence-Analysis Estimation of Care Pathway Exposure

Rural Malawian health centres concentrate antenatal care into a small number of visits, and the order in which those visits occur may shape whether a woman reaches a referral facility when an obstetric emergency develops. No observational data are used or claimed. The analysis characterises the design under a declared variance structure with between-cluster standard deviation of 6.0, residual standard deviation of 4.5, and intraclass correlation of 0.64. Power was estimated across 2000 design cells for cluster counts of 8, 16, 24 and 32 and effect sizes of 3, 5 and 8 percentage points. The design requires 54 clusters to detect a 5 percentage point difference at 80 per cent power. Sequence exposure is a sociologically distinct quantity from visit count, that its estimation requires design parameters calibrated to the clustering of rural health centres, and that the before-after-control-impact estimator is adequate only above a threshold of roughly fifty clusters. The contribution is a methodological specification linking antenatal visit ordering to emergency referral initiation, with explicit boundary conditions for its empirical application.