Medical Sociology of Pharmaceutical Detailer Visits and Antibiotic Prescribing in Nigerian Private Clinics: A Standardized-Patient Estimation of Detailing Exposure and Prescription Escalation

Pharmaceutical detailer visits are a routine feature of Nigerian private clinic practice, yet the causal effect of detailing exposure on antibiotic prescribing has not been credibly estimated because the standard observational designs used in this literature cannot separate detailing from the prescribing preferences that attract detailers to high-prescribing clinicians. the present analysis treats the before–after–control–impact (BACI) design as a candidate identification strategy for a standardized-patient study of detailing exposure and antibiotic escalation, and characterises its operating characteristics under a declared variance structure. Using a design-based analysis with between-cluster standard deviation 6.0, residual standard deviation 4.5 and intraclass correlation 0.64, 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.54 clusters are required to detect a 5-percentage-point escalation at 80% power, that the minimum detectable effect falls steeply as clusters increase from 8 to 32, and that the BACI interaction is estimable with acceptable precision only at the upper end of the cluster range. The contribution is a design specification for a study that has not yet been fielded, together with a demonstration that the credibility of detailing effects depends less on the standardized patient instrument than on the cluster structure of the comparison.