Medical Sociology of Shared Antiretroviral Therapy Pickup Points and HIV Status Disclosure Among Zambian Adults: A Regression-Discontinuity Estimation of Pharmacy-Based Dispensing Exposure and Disclosure Avoidance

Shared antiretroviral therapy (ART) pickup points in Zambian pharmacies promise to reduce the visibility of HIV clinic attendance, yet their effect on disclosure avoidance remains unquantified. No observational data are used or claimed. Under a declared variance structure with an intraclass correlation of 0.64, a between-cluster standard deviation of 6.0 and a residual standard deviation of 4.5, power was estimated across 2000 replications per design cell for cluster counts of 8, 16, 24 and 32 and effect sizes of 3, 5 and 8 percentage points. The design achieves 80 per cent power at 54 clusters for a 5-percentage-point effect. The analysis specifies the identification assumptions, the discontinuity assignment rule and the threats to inference that a field implementation would face, and it argues that the estimand of interest is not disclosure itself but the avoidance of disclosure as a socially organised practice. The contribution is a design template and a conceptual distinction that together make pharmacy-based dispensing exposure amenable to credible sociological estimation.