Evaluating the effect of usual source of dental care on access to dental services: comparisons among diverse populations.

Data collected from the International Collaborative Study of Oral Health Outcomes USA (ICS-II) research locations were used to evaluate the relationship between having a usual source of dental care (USDC) and access to dental services. The robustness of the USDC effect after reducing simultaneity bias was tested in the population-based samples using sensitivity analysis. Logistic regression results provided evidence that USDC was the strongest and most consistent predictor of a dental visit in the past 12 months regardless of geographic location, dental care delivery system, or cultural diversity of the population. Even removing cases that had a USDC for less than 1 or 2 years, the effect remained. From a policy perspective, USDC remains critical to understanding and explaining dental are utilization patterns. The findings suggest the need for designing interventions to increase the availability of a regular provider among vulnerable populations.