Teledentistry Triage Substitution and In-Person Dental Therapy Referral Accuracy in Namibian Rural Clinics: A Target-Trial Emulation of Diagnostic Pathways

Teledentistry triage is promoted as a substitute for in-person screening in rural African settings, yet the accuracy of referral decisions it generates has not been evaluated against the diagnostic standard that in-person dental therapy provides. No observational data were used: the analysis characterises the operating characteristics of the design under a declared variance structure with between-cluster standard deviation 6.0, residual standard deviation 4.5 and intraclass correlation 0.64. Power was estimated across 2000 design cells spanning 8, 16, 24 and 32 clusters and effects of 3, 5 and 8 percentage points. Fifty-four clusters were required to detect a 5 percentage point difference at 80% power. The results indicate that the before-after-control-impact estimator is adequately powered only at the upper end of the plausible effect range and that cluster count dominates the minimum detectable effect. Target-trial emulation of teledentistry substitution is feasible as a design but that its inferential yield depends on cluster availability rather than on the sophistication of the substitution model.