Q&A: Falls Decision Rule aims to reduce unnecessary CT scans in overcrowded EDs

Key takeaways:

• The rule was designed to be simplistic, with each item a yes or no question.
• It has a sensitivity of 98.6% and specificity of 20.3%.

A new clinical decision rule could help physicians determine which older ED patients who experienced a fall will require brain imaging, according to a study published in CMAJ.

The development of the Falls Decision Rule come as EDs “are managing a growing number of older adults who fall,” according to Kerstin de Wit, MD, an associate professor at Queen’s University in Canada, and colleagues.

The researchers conducted a prospective cohort study to derive a decision rule to identify patients who can have intracranial bleeding after experiencing a fall. The analysis included 4,308 patients (median age, 83 years; 64% women) across 11 U.S. and Canadian EDs.

De Wit and colleagues derived a rule with:

• sensitivity of 98.6% (95% CI, 94.9-99.6);
• specificity of 20.3% (95% CI, 19.1-21.5); and
• negative predictive value of 99.8% (95% CI, 99.2-99.9).

De Wit spoke to Healio about what the rule consists of, why the researchers developed it and more.

Healio: What is the Falls Decision Rule?

de Wit: The decision rule is for emergency physicians. It’s a rule that they can use for older adults attending the ED who have fallen. The rule helps physicians determine whether the patient should have a head CT scan or not.

Currently, we don’t have any clear guidance for many of these patients. So, we set out to derive a very simple decision rule with as few items as possible that a physician could apply at the bedside the moment they assess the patient.

Healio: What led to this rule being necessary for EDs?

de Wit: Lots of reasons. More recently, we’ve had terrible ED overcrowding, particularly in Canada but also in the U.S. and in Europe as well. Overcrowding, unfortunately, affects older patients disproportionately, and when the ED is full, then patients are left in corridors on stretchers or chairs. Very often it’s the elderly people who are left on the corridors.

There’s good evidence that the longer an older adult spends in the ED, the higher the risk that they’ll develop delirium. Clearly, delirium is unpleasant to experience, but also leads to hospital admission. At the moment, hospitals are critically full. We don’t have beds. So, when we admit patients, that means they stay in the ED for days.

Healio: Under the new rule, which patients should and should not undergo CT?

de Wit: The clinical decision rule that we developed has four items. We wanted to create a very simple rule where the answer to each question is yes or no, and if the answer is yes for any of these four items, then the patient has a scan. If the patient hit their head or is unsure whether they hit their head, they require brain imaging. The second item is whether they remember the events of the fall. The third item is a new abnormality on neurological examination, and the fourth item relates to patient frailty. If the patient needs help to do any of their normal activities — that would even include housework, heavy shopping, driving, dealing with finances or something more common, like bathing or dressing — then they would need a head scan.

Healio: What do the data suggest about its efficacy in identifying patients who do not require a CT?

de Wit: We deliberately designed the rule to have a very high sensitivity. We said that we would identify the most predictive items and add those to the rule until we have a rule that identifies more than 98% of all the cases of intracranial bleeding that we either diagnosed in the ED or over the next 6 weeks.

We need to do an independent validation study to retest the rule, as it were, in a separate group of patients, so that we can validate those findings.

Healio: What are the next steps toward implementing this rule in hospitals across Canada and the U.S.?

de Wit: We’ve applied to the Canadian Institutes of Health Research for further funding to do the validation study. Once we have the large-scale validation study, as long as it shows the rule is performing very safely, then the rule would be ready for ED physicians to use.

References:

• de Wit K, et al. CMAJ. 2023;doi:10.1503/cmaj.230634.
• New rule for emergency departments to safely reduce use of CTs after falls in older patients. https://www.eurekalert.org/news-releases/1009373. Published Dec. 4, 2023. Accessed Dec. 4, 2023.