Trauma Registry Linkage Latency and Post-Traumatic Stress Disorder Referral Completion in Rwandan District Hospitals: A Target-Trial Emulation of Data Reconciliation Delays

Delays between injury presentation and the reconciliation of trauma registry records with mental health referral logs create a form of immortal time in which survivors who later complete post-traumatic stress disorder (PTSD) referral are systematically misclassified as unexposed to timely linkage. No observational data are used or claimed. 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 replications per design cell for cluster counts of 8, 16, 24 and 32 and effect sizes of 3, 5 and 8 percentage points. The design attains 80% power at 54 clusters for a 5-percentage-point effect. The analysis specifies the estimand, the assignment procedure, the reconciliation-window definition and the sensitivity of power to cluster count, and it identifies the conditions under which linkage latency can be treated as a modifiable exposure rather than a proxy for unmeasured severity. The contribution is a design specification that separates the causal question from the data-reconciliation apparatus that ordinarily obscures it.