Dental hygiene therapy caregiver oral health literacy and child caries increment in Senegalese community programmes: a multilevel mediation analysis of counselling dose

Community oral health programmes in Senegal routinely deploy dental hygiene therapists to deliver caregiver counselling, yet the dose of that counselling is rarely measured and its mediating role in child caries increment remains unquantified. The framework treats counselling dose as a programme-level exposure, caregiver literacy as a cluster-level mediator and caries increment as a child-level outcome, and it formalises the decomposition of the total programme effect into direct and indirect components under latent-variable measurement of literacy. A worked illustration uses the DHS Program indicator 'Family planning messages at community meeting or event' (FP_EFPM_M_COM) for 15 African countries, 2021-2025, with a mean of 29.733 and a standard deviation of 17.495, to demonstrate the cross-country heterogeneity that any Senegalese programme evaluation must accommodate. The contribution is a pre-specified, assumption-explicit design for estimating counselling-dose mediation rather than a report of programme outcomes. The framework implies that evaluations which ignore counselling dose will attribute to literacy an effect that belongs to programme delivery, and it identifies the design conditions under which the indirect pathway can be credibly separated from confounding.