Clinical Decision Support System (CDSS)


A Clinical Decision Support System (CDSS) is a system used within a clinical setting to support clinical decision making. Clinical Decision Support Systems are based on evidence based medicine (EBM) to relay the best up to date information available to the physician or doctor. CDSSs are a result of top notch medical research welded with information technology and computer science.

CDSSs support healthcare workers in performing everyday functions by assisting in tasks that require the accurate interpretation of data. CDSSs provide evidence based knowledge in the context of patient specific data. The growing popularity of CDSSs is due to the growing evidence supporting the claim that they improve patient safety and quality of care by facilitating the practice of evidence based medicine.


There are numerous clinical tasks that a CDSS can perform or assist in. The list below shows some of the most common applications of a CDSS.
  • Alerts and Reminders: A CDSS will alert the doctor or physician when certain inputted data is alarming or a potential risk to the patient. For example, if a patient has a history of cardiac issues and the system reads that their blood pressure is abnormally high it can alert the doctor of the abnormality.
  • Diagnostic Assistance: Patient data can be compared to the system knowledge base in order to present possible diagnoses. This is beneficial when the clinician is not confident with his or her knowledge on a certain condition or if there is new medical knowledge that has recently come to light on a condition (i.e. a GP trying to assess a neurological problem) or when the patient's symptoms are complex or seemingly unrelated.
  • Prescription Decision Support: A specialized CDSS known as a Prescribing Decision Support System (PDSS) can check for drug-to-drug interactions, dosage errors, and drug contraindications such as patient allergies. Many systems also enable automated script generation and electronic transmission to the pharmacy, much like CPOEs (Computerized Physician Order Entry). PDSS is one of the most widely accepted and used CDSSs.
  • Information Retrieval: CDSSs can assist in the location and retrieval of appropriate and accurate clinical data which may be used for diagnosis or treatment planning. Depending on the complexity of the system, the CDSS may simply perform as a filter to search queries or be able to assess the importance, applicability, or utility of the information it retireves.
  • Image Recognition and Interpretation: Expert systems are now capable of interpreting clinical images ranging from simple X-rays to MRIs or CT scans. The greatest benefit can be seen when examining a series of images where a system may detect minute changes over time that may have been overlooked by a professional due to the minuteness.
  • Therapy Critiquing and Planning: Critiquing systems examine treatment plans looking for inconsistencies, errors, omissions, or potential contraindications. The system works by judging the proposed treatment against the patient data and known standards of care. Essentially, a critiquing system looks at a treatment plan in comparison to a set of "rules". A planning system, on the other hand, uses a knowledge base of treatment protocols and guidelines to actually assist in the creation of a treatment plan.


Internal Medicine Expert System
Glucose Regulation for Intensive Care Patients
Post-operative Expert Medical System
Image-based Clinical Diagnosis Support
Expert System Platform


Below are screenshots of the GRIP (Glucose Regulation for Intensive care Patients) system. GRIP is a computer program that monitors blood glucose in the intensive care unit. The program uses blood glucose values and other clinical information to advise nurses on how much insulin should be administered and how often glucose should be sampled.
The last two screen shots are those from a CDSS called DXplain. DXplain's Decision Support Systems is a widespread system that has evolved for over 25 years to be one of the best CDSSs.

Main Screen: A representation of the physical layout of beds on the ICU.

Patient Overview Screen: provides details on patient, the last glucose measurement, and care recommendations.patientscr.png

(Screenshots courtesy of //

DXplain: This first screenshot shows the basic page where the patient's information is processed.

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DXplain: This screen shows how CDSSs access knowledge or evidence based systems for accurate information.

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Screenshots courtesy of:


AHRQ National Resource Center for Health Information Technology

Related Terminology:

Knowledge Management Systems
Evidence Based Medicine - EBM
Clinical Decision Making
Expert Systems
Artificial Intelligence in Medicine (AIM)
Computerized Physician Order Entry (CPOE)
Prescribing Decision Support System (PDSS)


Guide to Health Informatics 2nd Edition