Many specialized clinical and information technology (IT) terms come into play in addressing the subject matter of this book, some of which may be jargon to those unfamiliar with a particular topic being discussed. Readers can consult online or print-based dictionaries for clarification of such terms. There has been a national effort to standardize definitions of several key health IT terms . We have generally followed these definitions, though they have not yet been widely adopted.
In CDS and medication management, words shape thinking, which translates to action that changes the environment in which we operate. We therefore define several key terms that are fundamental to the subject at hand. Although these terms can be used differently in other contexts, the definitions presented here serve as the foundation for the guidance provided in this book.
Clinical decision support. We use this term, broadly defined, to encompass a wide variety of approaches—increasingly but not exclusively computer-based—for delivering clinical knowledge and intelligently filtered patient information to clinicians and/or patients for the purpose of improving healthcare processes and outcomes. CDS includes knowledge-delivery interventions, such as targeted documentation forms and templates, relevant data presentation, order and prescription creation facilitators, protocol and pathway support, reference information and guidance, and alerts and reminders (see Table 1-1).
Clinical information systems. This term broadly refers to computer-based systems that manage patient-related data, for example, EMR, PHR, CPOE (computerized practitioner order entry), and the like. As previously noted, there are early attempts to standardize the definitions of selected key systems, although widely accepted definitions do not generally exist.
Medication errors. The National Coordinating Council for Medication Error Reporting and Prevention (NCC MERP)  has defined a medication error as "...any preventable event that may cause or lead to inappropriate medication use or patient harm, while the medication is in the control of the healthcare professional, patient, or consumer. Such events may be related to professional practice, healthcare products, procedures, and systems, including prescribing; order communication; product labeling, packaging and nomenclature; compounding; dispensing; distribution; administration; education; monitoring; and use."   NCC MERP has developed a taxonomy for categorizing medication errors and the associated harm to patients, summarized next.  This taxonomy informs medication error reporting programs, such as that provided by U.S. Pharmacopeia (USP) and the Institute for Safe Medication Practices (ISMP): 
- No Error
- Category A - Circumstances or events that have the capacity to cause error.
- Error, no harm
- Category B - Error did not reach patient (an “error of omission” does reach the patient).
- Category C - Error reached patient but did not cause harm.
- Medication reaches patient and is administered.
- Medication reaches patient and is not administered.
- Category D - Error reached patient and requires intervention to preclude harm (i.e., monitoring, lab tests).
- Error, harm
- Category E - Error may have contributed or resulted in harm that required intervention.
- Category F - Error may have contributed or resulted in harm that required initial or prolonged hospitalization.
- Category G - Error contributed or resulted in permanent patient harm.
- Category H - Error contributed or resulted in intervention necessary to sustain life.
- Category I - Error contributed or resulted in death.
Medication management. This term includes the full medication-use cycle in inpatient, ambulatory care and/or home settings, with emphasis on opportunities for CDS (see discussion and Figure 1-1 on page xx). Note that, in addition to helping optimize these process steps individually, a medication-management CDS program should continually measure and improve how CDS-mediated information delivery optimizes overall medication-related outcomes, such as pertinent morbidity, mortality, cost-effectiveness, and efficiency (see Chapter 7).
Medication use (appropriate). Ideally medications are used in a manner that minimizes, to the greatest extent possible, preventable harm caused by both errors of omission (such as failing to obtain appropriate follow-up data about a patient’s response to a medication) and commission (such as providing a medication to a patient for which they have a known life-threatening allergy). It likewise includes using medications effectively and efficiently to optimize health (such as ensuring that patients receive medications that are strongly indicated to minimize disease complications). This appropriate use is accomplished, in part, by applying the best evidence, clinical information, and care practices to decisions and actions throughout the medication use cycle — all of which can be supported through well-executed CDS.
Outcomes related to medication use. For the purposes of this book, medication use outcomes include the extent to which the therapeutic (or diagnostic) intent for the medication is achieved; the safety with which medications are used — for example, avoiding preventable adverse events - and the financial implications of medication use — for example, cost-effectiveness compared with alternatives.