Impact of California's Elimination of Medicaid Adult Dental Coverage on Emergency Department Visits for Dental Problems

Objectives: To examine the impact of elimination of Medicaid adult dental coverage on emergency department (ED) use for dental problems by Medicaid adult enrollees in California.

Methods: Interrupted time series, a quasi-experimental study, was conducted using a natural experiment in California, where Medicaid adult dental coverage was eliminated on July 1, 2009. State Emergency Department Databases (SEDD) for the state of California were acquired from AHRQ for 2006 to 2011. Primary diagnosis codes were used to select ED visits due to dental problems and other non-dental conditions for comparison. Segmented linear regression analyses were conducted and significance was determined at p-value<0.05.

Results: Before the elimination of Medicaid adult dental coverage, an average of 42.4 dental ED visits occurred each month per 100,000 enrollees which increased to 56.1 after the policy change. The policy change had a statistically significant immediate increase in the rate of dental ED visits per month (4.40 dental ED visits/ 100,000 enrollees/month, p-value=0.002). Certain subgroups, such as young adults, major racial-ethnic groups and residents of metropolitan areas were disproportionately impacted by the policy change. The average yearly inflation-adjusted costs associated with the ED dental visits increased 68% in the period after the policy change.

Conclusions: Eliminating Medicaid adult dental benefits leads to an immediate and significant increase in dental ED visits, and it has a differential effect on various subpopulations. The population affected by this policy is set to expand nationally under the ACA, and such evidence is critical to inform future policy decisions.