Dental therapy workforce density and emergency periodontal care utilisation in Malawian districts: a multilevel analysis of supply-threshold effects

Malawi's dental therapy workforce is among the thinnest in the region, yet the relationship between workforce density and emergency periodontal care utilisation has not been quantified at district level. The framework is specified as a two-level model with districts nested in regions, incorporating a piecewise-linear threshold term and a random intercept for region. Because no district-level utilisation data are available for Malawi, the paper develops the identification strategy, derives the threshold estimator, and calibrates the model against published workforce and population figures. The analysis is explicitly prospective: it specifies the data required, the estimation procedure, and the conditions under which the threshold parameter is identified. A secondary empirical component reports the distribution of a related DHS indicator—the percentage of injections given by a health care provider—across 14 African countries surveyed between 2021 and 2025 (N = 14, mean = 91.964, SD = 12.468, range 60.90 in Malawi to 99.70 in Kenya), which serves as a benchmark for the scale of cross-country heterogeneity in service-delivery indicators. Workforce density operates through a threshold mechanism rather than a linear one, and that this distinction has consequences for how dental therapy posts are allocated across districts.