"Big-data technology will eventually underpin the healthcare system, though to what extent and what that means to patients are questions needing to be asked. "
According to Wikipedia, big data is an all-encompassing term for any collection of data sets so large and complex that it becomes difficult to process them using traditional data processing applications.
Here's an overview article that looks at the likely benefits along with the issues that need to be resolved for Big Health Data to deliver benefits to healthcare:
techrepublic.com/article/bi...
I recommend everyone at least read the final section of the article Who owns EHR (Electronic Health Record) data?
Neil