Clinical decisions by doctors and nurses may result in suboptimal outcomes for the patient.

Most decision support systems aim to identify the best decision to take within a precise or estimated range.
The system behind a logical condition is very simple in the sense that it analyzes whether a measured variable is within a set of defined bounds or limits and initiates an appropriate output action.

One approach to create logical condition systems is through the use of decision tables that associate variable statements and definitions with an action to perform using a tabular form of representation. Decision tables are very good tools for the routine decision-making process defining ranges and limits of values and providing action outputs. Most decision tables provide if-then-else rules while others use true-vs.-false values to represent the alternatives to a condition and some tables may even use numbered alternatives or probabilistic representations for options.

In clinical settings, logical conditions are mostly used to deliver alerts, notifications and reminders to medical staff. For example, an alert may warn physicians during routine procedures that their patient’s blood pressure, pulse rate or breathing frequency is too low, a medication reminder may be provided for nurses and a notification may advise doctors to discuss disease associated conditions with the patient (such as exercise or eating habits).
It is possible to link multiple variables together to create more complex conditions to help decision making in different fields of medicine. If decision tables are used, they need to contain rules that specify conditions that must be satisfied for a given diagnostic category.

There are several examples of decision tables for diagnostic support such as blood pressure diagnosis: if the systolic blood pressure is within a range of 90-120 mmHg, then it is defined as healthy whereas if the value is within 140-160 mmHg then it is stage one hypertension. Such tables are helpful tools for interpreting electrocardiograms (ECGs) by comparing measured lengths of intervals and waves with the defined rules, within the logic system. Other medical systems use decision tables for classifying tumors e.g. whether a detected tumor is related to another primary brain tumor or unrelated.

The increased awareness that alerts, reminders and diagnostic support bring into the clinic there decreased risk that the doctors, nurses, and other staff provide less than optimal care for the patient.