County Healthcare Expenditure and Utilization Database. Transfers between hospitals
were considered a single hospitalization. The primary reason for admission was categorized
as cardiovascular (ICD-9 codes 390-459) or non-cardiovascular (all other codes) based on
principal ICD-9 code. Outpatient visits were categorized by provider type (cardiologist vs.
non-cardiologist). As we were unable to identify provider type for some visits in the county
after July 1, 2010, this analysis was restricted to patients that died prior to that date. Tests,
imaging and outpatient procedures were not counted as outpatient visits and were not
quantified.