Episode 56 The Stiell Sessions: Clinical Decision Rules and Risk Scales

There are hundreds of clinical decision rules and risk scales published in the medical literature, some more widely adopted than others. Dr. Ian Stiell, the father of clinical decision rules, shares with us his views and experiences gained from co-creating some of the most influential CDRs and risk scales to date. In discussion with Dr. Hans Rosenberg, he explains the criteria for developing a CDR, the steps to developing a valid CDR, how best to apply CDRs and risk scales to clinical practice, and the hot-off the-press new Ottawa COPD Risk Score and Ottawa Heart Failure Risk Score for helping you with disposition decisions. It turns out that in Canada, we discharge about two thirds of the acute decompensated heart failure patients that we see in the ED, while the US almost all patients with decompensated heart failure are admitted to hospital. Dr. Stiell's new risk scores may help physicians in Canada make safer disposition decisions while help physicians in the US avoid unnecessary admissions.

 

COUNTERPOINT: Dr. Anand Swaminathan's rant on the use and barriers to use of Dr. Stiell's clinical decision rules and risk scales in the United States...

Link to The Stiell Sessions Part 2: Update in Atrial Fibrillation - The New Guidelines



Written Summary & Blogpost Prepared by Dr. Michael Kilian, edited by Dr. Anton Helman, December 2014

 Cite this podcast as: Helman, A, Stiell, I, Rosenberg, H. The Stiell Sessions: Clinical Decision Rules and Risk Scales. Emergency Medicine Cases. December, 2014. https://emergencymedicinecases.com/episode-56-stiell-sessions-clinical-decision-rules-risk-scales/. Accessed [date].

Criteria For Developing a Clinical Decision Rule



In order to develop a useful clinical decision rule (CDR), a number of criteria must be met. Firstly, the condition needs to be relatively common. Rare conditions will not have the necessary volume of data to generate high quality decision rules. In addition to being a common complaint or illness, there must also be a perceived inefficiency or clinical variability in practice with regards to the workup of the patient. For example, the inefficiency can be an over-use or under-use of a particular resource (imaging, blood tests etc.) which, given a lack of evidence, physicians have different approaches to. Lastly, the clinical question that leads to the inefficiency needs to be answerable with only a handful of clinical variables.

Clinical Decision Rules vs Risk Stratification Scales

More complex conditions such as CHF and COPD have a spectrum of severity and acuity. Their management cannot be reduced to a binary question, since multiple factors need to be taken into consideration. This is in contradistinction to the Ottawa Ankle rule, in which a binary question is asked – does this patient require an x-ray or not? As a result, these complex conditions require risk stratification scales (rather than CDRs), which estimate the risk of a bad outcome. These scales can help physicians decide what the appropriate management and disposition for the patient would be.

The Development of a Clinical Decision Rule



Before CDRs can be safely applied in clinical practice they undergo a rigorous development process. The four phases of development include derivation, validation, implementation and studying the barriers to adoption. Although the rule is derived and published in the literature,