UCI Libraries has a wide range of data sets.
When seeking health statistics, you may want to start with the valuable and highly recommended resources found on the Health Statistics Guide (see http://libguides.lib.uci.edu/healthstatistics) which will direct you to a variety of health related statistical information and provide definitions of measures and data elements.
The first four links below are great general links to get you into statistical websites. Following the first four links are sites more specific to certain types of statistics (HIV/AIDS, Cancer, etc.), listed in alphabetical order. In addition there are resources for statistics at the local, state, federal and international levels, for different applications such as specific diseases, conditions, demographic patterns, census trends and other topics.
Find information on: