Table 2.

Examples and brief overview of routinely collected data sources

	Description	Major data elements
Surveillance, Epidemiology, and End Results Program (SEER)12	U.S. cancer registry that includes approximately 35% of the U.S. population. Data are representative of the U.S. population and are drawn from 12 state registries, 4 metropolitan multicounty areas, and 3 indigenous registries	Patient demographics, primary tumor site, tumor morphology and stage at diagnosis, first course of treatment, and followup for survival
Medicare/Medicaid13	National records of reimbursement related to subsidized care provided to U.S. citizens >65 years of age (Medicare), or low-income adults, those with a physical disability, and children (Medicaid)	Part A covers non-physician inpatient care, Part B covers physician services, and Part D includes optional drug coverage Demographic and geographic information, diagnosis (ICD code) and procedures (CPT or HCPC codes) and national drug codes are included in each respective part
National Inpatient Sample (NIS)	National representative sample of discharges (20%) of children and adults from all community hospitals (includes those with both Medicare/Medicaid, private insurance, and no insurance)	Discharge abstracts include ICD codes for admission and discharge diagnoses, demographics, hospital characteristics, payment source, length of stay, severity and comorbidity measures
American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP)	Voluntary hospital-level program that compares risk-adjusted outcomes after surgical procedures. Over 650 hospitals (primarily from the U.S.) are participating in order to compare their post-surgical complications to national averages	Demographics, operative procedure (CPT code), selected risk factors (such as diabetes, smoking, medical comorbidities), preoperative laboratory values, length of stay, and specific complications that occur within 30 days of the initial OR (such as unplanned reoperation, stroke, bleeding, urinary tract infection, and wound infection)