Types of health economics research datasets:
• Health components of data sets traditionally used by economists
• Longitudinal surveys of health and economic behavior
• Data on employer-provided insurance
• Cross-sectional surveys of households that focus on health
• Data on health care providers
• Vital statistics
This 2013 article from the American Health Information Management Association offers a useful introduction to the different kinds of publicly-available health and healthcare data that are available. The authors briefly explain how data from individual patient medical records is aggregated into larger datasets, discussing some of the privacy considerations involved.
This helpful chart from the National Center for Health Statistics (CDC) describes and compares NCHS surveys and data collection systems. (includes surveys of both the general public and providers, links to historical and current data, and information about sample sizes, data sources, and frequency).