What is Clinical Decision Support (CDS)?
What is the official reasoning behind making CDS mandatory for Electronic Health Record (EHR) applications?
This ends up getting a little bogged down in compliance mumbo jumbo, but Clinical Decision Support is defined by the US centers for medicare and medicaid services as:
Health information technology functionality that builds upon the foundation of an electronic health record to provide persons involved in care processes with general and person-specific information, intelligently filtered and organized, at appropriate times, to enhance health and health care.
I've spelled out the abbreviated terms in this definition.
You can understand CDS as a general concept (electronic tools to support clinical decision making), but generally, it's used to refer to US requirements for "meaningful use" of an electronic health record.
In US healthcare, the phrase "meaningful use" is almost a synonym for electronic health record (on wikipedia, meaningful use redirects to the EHR article), but the phrase comes from the HITECH act, a 2009 law that gave incentive payments for transitioning to electronic health records (and using those electronic records in a meaningful way).
Strictly speaking, you can practice medicine in the US without using an electronic health record or clinical decision support, but, if you do, you won't have access to funds the federal government has set aside for modernizing health care, and in some cases, you will also be paid less for services. EHR rules are typically described as "required" when they mean "required in order to qualify as meaningful use".
One of the main goals of the HITECH act (see link above) was development of a health information technology infrastructure that improved health care quality and reduced errors. Decision support tools directly support these goals. HealthIT.gov, the website for the office set up by the HITECH act, has a page that spells out the official reasons. Some highlights:
CDS has a number of important benefits, including:
Increased quality of care and enhanced health outcomes
Avoidance of errors and adverse events
Improved efficiency, cost-benefit, and provider and patient satisfaction
Health information technologies designed to improve clinical decision making are particularly attractive for their ability to address the growing information overload clinicians face, and to provide a platform for integrating evidence-based knowledge into care delivery
Of note, though one of the official reasons for requiring CDS for meaningful use is "growing information overload", in order to qualify, you only need 5 clinical decision support interventions, a drug-drug and drug-allergy check. I believe these are useful things to do, but targeting 5 quality measures seems fairly limited if the goal is to help with "information overload". If it's truly "general and person specific information, intelligently filtered and organized, at appropriate times", I hope we can move beyond pop up alerts for a few quality measures.