You just check in UCI Machine repository site. The following is the URL

http://archive.ics.uci.edu/ml/

Try this: http://apps.himss.org/foundation/histdata.asp

Please check this link .. 

http://dashboard.healthit.gov/datadashboard/data.php

I need research topics in healthcare data mining

You should look at MIMIC:

https://mimic.physionet.org/

https://openmrs.org/download/