Clinical Decision Support (CDS) is an early, important, and particularly interesting domain within health informatics. Its purpose is to provide clinicians, patients, and others with knowledge and personalized information, intelligently filtered or presented at appropriate times, to enhance health and health care. It is a critical component of the IOM’s vision of a Learning Health System that we introduced in the first article since it is the vehicle for feeding knowledge obtained from the care of prior patients back to providers caring for current patients or even directly to those patients.

A universal health app platform to support informatics-based innovations in care delivery, no matter what the underlying EMR, was a long-held goal of the academic health informatics community. In 2010, the federal government awarded U.S. $15 million to the Boston Children’s Hospital Computational Health Informatics Program and the Harvard Medical School Department of Biomedical Informatics to create and initially develop just such an app platform.

The first article of this series mentioned that, after the success of its new messaging standard for electronic health record (EHR) systems, Health Level 7 (HL7) found it difficult to develop and widely deploy a standard for the rich representation of clinical data for use in patient care. This was due, in large part, to the complexity of medicine and the resulting complexity of the clinical terminologies developed to represent it.

It is hard to conceive of a better rationale for healthcare interoperability than the management of chronic disease. People in advanced, industrialized countries are living longer, and chronic disease rates among the elderly are on the rise in part because of lifestyle issues, such as obesity and inadequate exercise. As a result, the care of chronic diseases (such as hypertension, heart disease, diabetes, chronic lung disease, and chronic kidney disease) accounts for well over 90% of spending by Medicare, the U.S. health insurance program for people age 65 and over. The Agency for Healthcare Research and Quality has found that the top 5% of patients with four or more chronic diseases are responsible for 30% of all Medicare chronic disease spending. While just 17% of Medicare patients live with more than six chronic conditions, they account for half of all spending on beneficiaries with chronic disease.