District Hospital Trauma Mental Health Screening Triage Acuity Misclassification and Post-Traumatic Stress Disorder Referral Loss in Tanzanian Clinics: A Regression Discontinuity Analysis of Acuity Threshold Reassignment

District hospital trauma triage in Tanzania assigns patients to acuity bands that determine whether mental health screening occurs, yet the threshold rules governing reassignment have never been evaluated for their effect on post-traumatic stress disorder (PTSD) referral. the present analysis treats acuity threshold reassignment as a regression discontinuity problem: patients just above and just below the reassignment cut-off are comparable in injury severity but differ in whether they enter the screening pathway. Using the DHS Program indicator 'Current users most recent supply or information from a government health center' (FP_SRCM_W_GHC) across 36 African countries and 150 country-survey observations from 1990 to 2025 (mean 25.261, SD 18.895, range 1.50 in Morocco to 51.89 in Zambia), the analysis specifies a sharp regression discontinuity design in which the running variable is the triage acuity score and the cut-off is the reassignment threshold. Threshold reassignment creates a local randomisation in screening exposure that is routinely exploited clinically but never analysed statistically, and that the resulting referral loss is concentrated among patients whose injuries are severe enough to trigger reassignment but not severe enough to trigger independent mental health consultation. The contribution is a formal specification of the misclassification mechanism, a set of testable discontinuity predictions, and a methodological template for auditing triage thresholds in low-resource trauma systems. No primary clinical data were collected; the paper is a methodological and conceptual analysis that uses the DHS indicator as a contextual benchmark for the population of health-system users from which trauma patients are drawn.