Community-Based Trauma Mental Health Task-Sharing Ratio and Post-Traumatic Stress Disorder Symptom Detection Among South Sudanese Refugees: A Multilevel Analysis of Caseload Thresholds

Task-sharing models of trauma mental health care assume that community health workers can detect post-traumatic stress disorder (PTSD) reliably when caseloads remain manageable, yet the threshold at which detection accuracy deteriorates has not been formally specified. The framework proposes that detection sensitivity follows a non-linear function of caseload, with a threshold beyond which sensitivity declines sharply because workers cannot sustain the structured symptom inquiry required for reliable identification. The analysis specifies the parameters of this threshold model, examines its implications for programme design, and identifies the conditions under which task-sharing ratios can be expected to support adequate detection. The contribution is a formal statement of the caseload-detection relationship that can guide the allocation of community health workers in refugee mental health programmes and that generates testable propositions for future empirical evaluation.