District Hospital Surgical Capacity Concentration and Post-Injury Trauma Mental Health Follow-Up in Rwandan Referral Networks: A Multilevel Analysis of Decentralization Thresholds

Rwanda's district hospital system concentrates surgical capacity in a small number of referral facilities, yet post-injury mental health follow-up is nominally organised at the district level. 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, the analysis characterises the distribution of government health-centre contact among current users. The mean indicator value was 25.261 (SD = 18.895), with country values ranging from 1.50 in Morocco to 51.89 in Zambia. A multilevel framework is specified in which district surgical capacity concentration operates as a network-level exposure and post-injury mental health follow-up as a facility-level outcome, with decentralisation thresholds modelled as non-linearities in the exposure-outcome gradient. Surgical capacity concentration and mental health follow-up are coupled through referral pathways, and that decentralisation thresholds are best understood as network properties rather than facility attributes. The contribution is a specification of the threshold mechanism and a methodological framework for estimating it in referral networks where surgical and mental health data are collected at different levels.