District Hospital Blood Transfusion Delay Intervals and Post-Traumatic Stress Symptom Persistence in Kenyan Emergency Departments: A Target-Trial Emulation of Resuscitation Timing Thresholds

Delays in blood transfusion for haemorrhaging trauma patients in Kenyan district hospitals are common, yet the causal effect of resuscitation timing on subsequent post-traumatic stress symptom persistence remains poorly characterised. Because no observational data are available, the analysis characterises the operating characteristics of the proposed estimator under a declared variance structure: between-cluster standard deviation of 6.0, residual standard deviation of 4.5, and intraclass correlation of 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. The analysis indicates that 54 clusters are required to detect a 5-percentage-point effect at 80% power. The framework provides a template for evaluating resuscitation timing thresholds as modifiable determinants of trauma-related mental health outcomes in resource-constrained emergency care settings.