Trauma Ward Mental Health Visitor Restriction Policy Exposure and Post-Traumatic Stress Disorder Symptom Trajectories Among Ghanaian Inpatients: A Target-Trial Emulation of Social Support Deprivation Windows

Visitor restriction policies in trauma wards disrupt social support during a period when inpatients are at elevated risk of post-traumatic stress disorder (PTSD). Estimating the causal effect of such policy exposure is complicated by the fact that restriction is not randomised and that the relevant exposure window—the period during which social support is withdrawn—is itself a function of ward conditions and patient acuity. No observational data are used or claimed. The analysis specifies a between-cluster standard deviation of 6.0, a residual standard deviation of 4.5, and an intraclass correlation of 0.640, and evaluates power 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 results indicate that 52 clusters are required to detect a 5-percentage-point effect at 80% power. The framework provides a template for causal inference on social support deprivation in African trauma settings and identifies the design conditions under which policy effects on PTSD symptom trajectories can be reliably estimated.