Big data: a new look at old problems.

Abstract

The term Big Data is an elusive term with a definition that is not commonly agreed upon. According to a recent definition, the term would encompass any data that is around a petabyte (1015 bytes) or more in size.1 In health informatics research, Big Data of this size is quite rare. Nevertheless, data used for health informatics research can be considered Big Data in terms of their richness of clinical information and complex structure and may represent an important source of information relevant to the clinical decision-making in real-world patient settings.2 Rapsomaniki et al. 3 used samples of national, ongoing, unselected record sources to assess three outcomes: all-cause death; a composite of myocardial infarction (MI), stroke, and all-cause death; and hospitalized bleeding. Patients aged 65 years and older entered the study 1 year following the most recent discharge for MI. The data bases used were the Echantillon Generaliste des Beneficiaires from France, the CALIBER research platform of primary care linked via Myocardial Ischaemia National Audit Project (MINAP), the Hospital Episodes Statistics database, and the nationwide cause-specific mortality database from England, the National Inpatient Register, the Swedish Prescribed Drug Register, and the Cause of Death Register from Sweden, and the Medicare database from the USA. The information from these large administrative databases provided an overview of the effectiveness of specific procedures. For example, coronary artery bypass graft and coronary angioplasty results were described in the four populations. The study found that compared with patients from France (64.6%), patients from Sweden (61.3%), England (42.8%), and the USA (59.8%) were less likely to have undergone revascularization either by coronary artery bypass graft or percutaneous coronary intervention (PCI). Unadjusted 3-year cumulative risk of death was considerably lower among English patients (19.6%) than the corresponding figures from the USA (30.2%), Sweden (26.9%), and … [↵][1]*Corresponding author. Tel: +39 051 347290, Fax: +39 051 347290, Email: raffaele.bugiardini{at}unibo.it [1]: #xref-corresp-1-1