Clinical Decision Rules

What are clinical decision rules? Clinical decision rules are tools that help with clinical decisions by organizing selected patient data. The purpose of these rules is to help clinicians make better, more efficient decisions. In many cases, they help assess the level of risk a patient has for a given disease. In other words, they are risk stratification tools. Risk stratification helps clinicians determine the extent of further workup and treatment the patient needs.

Examples of such tools at the time of this writing, include the NEXUS cervical spine criteria, HEART score and Well’s criteria for pulmonary embolism.

These can be useful tools. However, we must use them wisely.

How can we use these tools wisely? We can start by treating these rules as a guide that we can use to help us in our decision making. The rules are not the end all be all that overrules clinical judgement. They exist to make clinical judgement better by steering that judgement in the right direction.

The rules can be a starting point, a reference point from which a clinician can start making a clinical decision. Once you have that starting point you have a cognitive anchor from which you can venture out to find other important details with less chance of getting lost in the confusing picture the patient may initially give you. Once you have these additional details, you can individualize your assessment or treatment of the patient, because you will have the big picture.

These rules do not take every possible circumstance into consideration. Remember, these are just a starting point in decision making. They can give a framework upon which you can place the rest of the patient data. For example, a patient could have tachycardia and palpitations with no other symptoms, you could initially be considering a PE based on Well’s criteria, and will be more likely to keep an eye out for the subtle EKG changes that can come with a PE.

These tools can also defend your judgement. This is obvious when you are following the rules as written. But even when you go against the rule’s assessment, it gives you a reference point from which to make your defense. For example, you could write something like “patient has high HEART score, however, due to (insert strong evidence you have to the contrary here) acute coronary syndrome seems unlikely”.

Lastly they can be good educational tools. A junior clinician should have a structure with which to start assessing patients. Clinical decision rules that give a list of details to collect become a way to start learning about how a disease presents clinically. The problem comes when the learner believes the rule is all there is to know about assessing for that disease.

The next time you’re considering the utility of clinical decision rules, consider them as just another tool at your disposal. Like any other tool you might use to help you make clinical decisions, respect them for both their strengths and their weaknesses, and use them at their appropriate time. Use them wisely, meaning use them as guides, not as the absolute, last answer.

If you want to learn more about this topic or other, related topics in clinical decision making, check out my book: A Guide to Clinical Decision Making