Truven Health MarketScan Commercial Claims and Medicare Supplemental Databases is used. The Truven Health MarketScan® Research Databases capture person-specific clinical utilization, expenditures, and enrollment across inpatient, outpatient, prescription drug, and carve-out services. Individuals enrolled in the MarketScan databases are largely representative of the United States population in terms of age, sex, and type of health insurance coverage. The data come from a selection of large employers, health plans, and government and public organizations and contain claims from approximately 100 employers, health plans, and government and public organizations representing about 50 million covered lives across all age groups. The data elements to be used in the proposed study will include health plan enrollment records, participant demographics, inpatient and outpatient medical claims and outpatient prescription drug dispensing records.