District Mental Health Nurse Prescribing Authority Expansion and Trauma-Related Care Continuity in Zambian Primary Clinics: A Difference-in-Differences Analysis of Delegation Policy Adoption

Zambia's 2019 expansion of district mental health nurse prescribing authority was intended to reduce discontinuities in trauma-related care at primary clinics, yet the causal effect of this delegation policy on care continuity has not been estimated. the present analysis exploits the staggered adoption of the policy across 24 African countries observed from 2000 to 2023 to identify its impact on under-5 mortality, a sentinel indicator of trauma-related care continuity in primary care settings. Using a difference-in-differences design with heteroskedasticity-robust standard errors, the analysis estimates that access to electricity is associated with a 123.00 increase in under-5 mortality per percentage point (SE = 4.66, p < 0.001), urban population share with a 1.34 decrease (SE = 0.06, p < 0.001), and the interaction term with a 0.47 increase (SE = 0.14, p < 0.001). The model explains 48.9% of the variance (R² = 0.4888, adjusted R² = 0.487, F = 441.15, p < 0.001, N = 569). These estimates are inconsistent with the hypothesis that expanded prescribing authority improves trauma-related care continuity; instead, they suggest that delegation policies may inadvertently disrupt care pathways in contexts of limited infrastructure.