Community Mental Health Services Teleconsultation Substitution and Psychotropic Continuity Among Namibian Outpatients: A Target-Trial Emulation of Switching Pathways

Teleconsultation substitution in community mental health services raises a design question that cannot be answered by the substitution itself: whether the switching pathway it creates can be evaluated with sufficient precision to distinguish continuity-preserving from continuity-disrupting transitions. the present analysis characterises the operating characteristics of a before-after-control-impact (BACI) estimator for that purpose, using 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 replications per design cell for cluster counts of 8, 16, 24 and 32 and effect sizes of 3, 5 and 8 percentage points.56 clusters are required for 80% power at a 5-percentage-point effect, that the minimum detectable effect at 80% power falls steeply as clusters increase from 8 to 32, and that the estimator's sampling distribution is wide relative to the effects that teleconsultation substitution is expected to produce. The contribution is a design-characterisation framework that specifies the cluster counts and effect sizes at which a BACI evaluation of switching pathways can and cannot support inference, and it reframes the evidentiary problem of teleconsultation substitution as one of design precision rather than of substitution technology.