Potentially Preventable Medical Hospitalizations and Emergency Department Visits by the Behavioral Health Population.

This study investigated geographic variation in potentially preventable medical outcomes that might be used to monitor access to high-quality medical care in the behavioral health population. Analyzing public and non-public data sources from California on adults admitted between 2009 and 2011 to all non-federal licensed medical inpatient (N = 6,603,146) or emergency department units (N = 21,011,958) revealed that 33.6% of nearly 1 million potentially preventable hospitalizations and 9.8% of 1.5 million potentially preventable emergency department visits were made by people with mental or substance use disorder diagnoses. Across California counties or county groups (N = 36), a higher preventable hospitalization rate in the behavioral health population was associated with higher poverty, higher primary care safety net utilization, and fewer mental health providers. Although further validation is required, rates of potentially preventable encounters, particularly hospitalizations, may be useful measures of access to high-quality care in the behavioral health population.