Oral Hygiene Instruction Language Concordance and Dental Therapy Treatment Completion Among Ethiopian Urban Migrants: A Multilevel Analysis of Communication-Mediated Attrition

Language concordance between dental therapists and patients is widely assumed to improve treatment completion, yet the mechanism by which communication operates on attrition remains underspecified. The model distinguishes three pathways—instruction comprehension, therapeutic alliance, and perceived discrimination—through which language discordance may raise the hazard of non-completion, and it specifies how clinic-level interpreter availability and provider language mix moderate these pathways. Because no primary data were collected, the paper is a theoretical and methodological contribution: it formalises the multilevel survival specification that would be required to estimate the model, derives the identification conditions under which communication-mediated effects can be separated from confounding by socioeconomic position and oral health literacy, and reports the design parameters for a planned 40-year computed cohort (1986–2025) of 162 country-survey observations drawn from the DHS Program indicator on contraceptive knowledge among married women, used here only to illustrate the distributional properties that a multilevel attrition analysis must accommodate (mean 91.776, SD 11.342, range 57.80–99.90). Language concordance is best understood not as a binary provider attribute but as a clinic-level communication regime whose effect on treatment completion is conditional on interpreter practice and on the migrant's prior dental help-seeking history. The contribution is a testable specification and a set of measurement recommendations for dental hygiene research in linguistically diverse African cities.