Dental Hygiene Therapy Scope-of-Practice Expansion and Periodontal Service Uptake in Ghanaian District Hospitals: A Difference-in-Differences Analysis of Regulatory Amendment Effects

Ghana's 2018 amendment to the Health Professions Regulatory Bodies Act expanded the scope of practice for dental hygienists and therapists, permitting them to perform periodontal assessments and non-surgical periodontal therapy independently in district hospitals. Using a difference-in-differences design with district hospitals as the unit of analysis, the study compares pre- and post-amendment periodontal service volumes in hospitals exposed to the expanded scope against those in comparison hospitals where the amendment was not implemented during the observation window. The analysis draws on routine service statistics from 135 hospital-year observations across 36 districts, spanning 1994 to 2025. The mean periodontal service uptake was 32.358 procedures per 10,000 outpatient visits (SD = 15.598), with substantial heterogeneity across districts. The difference-in-differences estimates indicate that scope-of-practice expansion was associated with a statistically significant increase in periodontal service uptake, though the magnitude varied by baseline workforce density and hospital type. The findings suggest that regulatory amendments permitting expanded dental hygiene therapy practice can meaningfully increase access to periodontal care in resource-constrained district hospital settings, but that the effect depends on the availability of trained personnel and supportive institutional conditions.