California Ambulatory Surgery Data, January - June 2009

The dataset is released twice a year and contains files for ambulatory surgery and emergency data. Ambulatory Surgery data include encounters from general acute care hospitals and licensed free standing ambulatory surgery clinics, during which at least one ambulatory surgery procedure is performed. Emergency Department data includes encounters from hospitals licensed to provide emergency medical services. To protect patient confidentiality, records with unique combinations of certain demographic variables will have one or more of those variables masked. These are detailed in Appendix A of the documentation.Each record in the dataset consists of one outpatient encounter for each time a patient is treated. Data collected for these encounters include demographic, clinical payer, and facility information.