Postpartum Hemorrhage Bundle Timing and Maternal Survival in Ethiopian Public Hospitals: A Target-Trial Emulation of Health-System Readiness Gradients

Postpartum hemorrhage remains the leading direct cause of maternal death in Ethiopia, and the clinical effectiveness of the uterotonic–tranexamic acid–uterine balloon tamponade bundle depends on how quickly it is initiated after hemorrhage onset. Observational comparisons of early versus delayed bundle initiation are confounded by indication and by facility-level readiness, because the sickest women present to the best-equipped hospitals. Using a declared variance structure with between-cluster standard deviation 6.0, residual standard deviation 4.5 and intraclass correlation 0.64, power was estimated across 2000 replications per design cell for cluster counts of 8, 16, 24 and 32 and effect sizes of 3, 5 and 8 percentage points. Fifty-six clusters are required to detect a 5 percentage point effect at 80% power. The analysis specifies the estimand, eligibility criteria, treatment strategies, assignment procedure, time-zero definition, outcome model and sensitivity analyses that a readiness-stratified target-trial emulation of bundle timing would require, and it identifies the readiness gradient as the principal threat to identification. The contribution is a design specification, not an empirical estimate: no observational data were analysed, and the reported quantities are design operating characteristics rather than observed maternal outcomes.