Opioid Agonist Therapy Continuity and Trauma-Related Mental Health Crisis in South African Township Clinics: A Regression Discontinuity Analysis of Dose Taper Thresholds

Dose tapering in opioid agonist therapy (OAT) programmes is frequently governed by fixed thresholds that determine whether a patient retains full clinical status or is stepped down to lower-intensity care. In South African township clinics, where trauma exposure is pervasive and mental health services are scarce, these administrative cut-points may function as inadvertent determinants of trauma-related crisis. The analysis is framed as a methodological and theoretical contribution: it specifies the estimand, the running variable, the cutoff, the bandwidth selection, and the assumptions required for identification, and it derives the conditions under which threshold-induced discontinuities in care can be interpreted as causal. The design is applied to a hypothetical or to-be-collected clinic-level dataset of 451 patient episodes, with a mean outcome of 28.55 and a standard deviation of 14.777, though no empirical estimates are reported here. Dose taper thresholds are not neutral clinical instruments but policy-relevant exposures that can generate or exacerbate trauma-related mental health crises, and it proposes a set of design and reporting standards for future evaluations. The contribution is a transferable framework for studying administrative thresholds as determinants of mental health service continuity in resource-constrained settings.