Big Data is more than a buzzword, it raises high expectations about how the massive treatment of data may deliver new results. At NEJM you'll find an article that explains general implications for health care:
Two key “learning” applications of big health care data that hold the promise of improving patient care are the generation of new knowledge about the effectiveness of treatments and the prediction of outcomes. Both these functions exceed the bounds of most computer applications currently used in health care, which tend to offer physicians such tools as context-sensitive warning messages, reminders, suggestions for economical prescribing, and results of mandated quality-improvement activitiesAt JEP, you'll find an article by Hal Varian that shows the new challenges for econometrics:
Conventional statistical and econometric techniques such as regression often work well, but there are issues unique to big datasets that may require different tools. First, the sheer size of the data involved may require more powerful data manipulation tools. Second, we may have more potential predictors than appropriate for estimation, so we need to do some kind of variable selection. Third, large datasets may allow for more flexible relationships than simple linear models.All in all, you'll be convinced that it is more than a buzzword.
PS. You may find an example of application of big data in our recent article in Gaceta Sanitaria.