Case
81M presents after he fell backwards from his own height. He can’t recall if he hit his head and his neurological review of systems is otherwise normal. His past medical history includes dyslipidemia, HTN, and Glaucoma. Medications include rosuvastatin, metoprolol, and timolol drops. He is mobile and independent at baseline. His vitals, GCS, and exam are all normal.
The patient was sent from a walk in clinic for a CT head to rule out an intracranial injury.
As the patient does not meet the inclusion criteria for the Canadian CT head rule (no witnessed disorientation, amnesia, or LOC), you wonder if there is a way to predict who doesn’t need a CT head.
The article
Derivation of the Falls Decision Rule to exclude intracranial bleeding without head CT in older adults who have fallen
Kerstin de Wit, Mathew Mercuri, Natasha Clayton, Éric Mercier, Judy Morris, Rebecca Jeanmonod, Debra Eagles, Catherine Varner, David Barbic, Ian M. Buchanan, Mariyam Ali, Yoan K. Kagoma, Ashkan Shoamanesh, Paul Engels, Sunjay Sharma, Andrew Worster, Shelley McLeod, Marcel Émond, Ian Stiell, Alexandra Papaioannou and Sameer Parpia; for the Network of Canadian Emergency Researchers
CMAJ December 04, 2023 195 (47) E1614-E1621; DOI: https://doi.org/10.1503/cmaj.230634
How was the Falls Decision Rule study designed?
This is a large, prospective, multicentre study to derive a clinical decision tool to identify elderly patients who can safely forgo a CT scan of their head after a ground level fall or out of a bed.
Patients were assess for the following predictors:
age; sex; head impact on falling; loss of consciousness; amnesia; history of previous major bleed; cirrhosis; previous ischemic stroke; chronic renal impairment; Glasgow Coma Scale reduced from baseline; bruise or laceration on the head; new abnormality on neurologic examination; hemoglobin < 10 g/L; platelet count < 80 × 109/L; anticoagulant therapy; antiplatelet therapy; and Clinical Frailty Scale ≥ 5 (impairment of high order IADLs – see scale below)
Clinicians had to fill out these variables before they could view CT head results (if one was ordered).
Patients were followed up to 42 days (based on expert consensus) by chart review.
The study was conducted at 11 different EDs in Canada and the USA, with 4308 patients enrolled.
What types of patients did they include?
- Age 65 or older
- Fall from standing on level ground, off a chair or toilet seat, or out of bed
- Presenting within 48 hours
Who was excluded?
- Previously enrolled
- Lived outside the hospital catchment area
- Transferred from another hospital
- Left before completion of their medical assessment
- If 2 or more variables were missing
What was the outcome of interest for the Falls Decision Rule?
- The clinical outcome was clinically important intracranial bleeding as bleeding that subsequently received medical or surgical treatment within 90 days, or that led to death within 90 days of the intracranial bleed.
How did they derive the clinical decision tool?
- They used logistic regression – a type of algorithm that tries to predict the outcome of interest based on a mathematical combination of the predictor variables
- They randomly sampled the population 1000 times, and each time calculated the model
- They picked the variables that appeared the most times and that would achieve 98% sensitivity
What did they find for the Falls Decision Rule?
- 50% had hit their head when they fell, 26% were on anticoagulant medication and 35% were on antiplatelet medication
- Clinical decision rule derived is
- Definitely no history of head injury
- The patient can confirm they have no amnesia of the fall
- There is no new abnormality on neurologic examination, and
- The Clinical Frailty Scale score is less than 5
Source: CMAJ December 04, 2023 195 (47) E1614-E1621; DOI: https://doi.org/10.1503/cmaj.230634
In these cases, CT imaging can be deferred safely according to the Falls Decision Rule
- Sensitivity 98.6% (95% CI 94.95%–99.6%), specificity 20.3% (95% CI 19.1%–21.5%) and negative predictive value 99.8% (95% CI 99.2%–99.9%) for clinically important injury
- They also post-hoc derived a more specific rule
- Definitely no history of head injury, and no new abnormality on neurologic examination.
- Sensitivity of 95.0% (95% CI 90.0%–97.0%), but a higher specificity of 38.0% (95% CI 36.6%–39.5%)
Important considerations and take away message for the Falls Decision Rule
- Well designed study, multi-center, with good follow-up period
- Low rates of positive outcome may lead to falsely elevated sensitivity
- Rate of missing variables were high, although the patients with these variables did not seem to be much different than the patients included
- Clinical outcome was based on whether or not the patient presented back to the hospital (or hospital network); there is a possibility that clinically important outcomes could be missed
- Neither anticoagulation or antiplatelet medication use were found to be predictors of clinically important outcomes
- The clinical frailty score is an important variable for predicting outcomes, and should be considered as part of your standard assessment of older patients
- The tool, while promising, still needs validation in multiple sites and settings to understand its real world effectiveness.
Case conclusion
After conducting a careful neurological exam, and undergoing shared decision making with the patient, you agree to forgo CT imaging given the patient’s reassuring history, exam, and risk factors.
Reference
Derivation of the Falls Decision Rule to exclude intracranial bleeding without head CT in older adults who have fallen. Kerstin de Wit, Mathew Mercuri, Natasha Clayton, Éric Mercier, Judy Morris, Rebecca Jeanmonod, Debra Eagles, Catherine Varner, David Barbic, Ian M. Buchanan, Mariyam Ali, Yoan K. Kagoma, Ashkan Shoamanesh, Paul Engels, Sunjay Sharma, Andrew Worster, Shelley McLeod, Marcel Émond, Ian Stiell, Alexandra Papaioannou and Sameer Parpia; for the Network of Canadian Emergency Researchers. CMAJ December 04, 2023 195 (47) E1614-E1621; DOI: https://doi.org/10.1503/cmaj.230634
I apologize but i am left confused. At the beginning of the article it is noted that the patient “can’t recall if he hit his head.” Yet, at the conclusion, “you agree to forego CT imaging.” That seems to contradict the rule???? In addition, I am not clear what the rule, as presented, adds to the Canadian CT Head Rule, since if we are certain that the patient did not strike their head, then why would we call for a CT of the head? I know I must be missing something here, and apologize if I am.
There is no mention of the fact that if the clinical frailty score is above 5, then CT is unlikely to change management as they would not be fit for surgery .
With no mention of assessing for benefit of scan to change management, this decision ‘rule’ condemns older frailer people to unnecessary scans and follow up. Care of elderly people, especially the frailer elderly, is not a ‘one size fits all’ plan putting them on a conveyor belt to investigation and treatment that they do not want and that is of no benefit to them. It isn’t the same as it is in children and younger adults where you would expect to proceed to maximal therapy. With the patient who ‘doesn’t remember’ due to severe dementia, and who will require sedation simply to perform the scan as they will not understand what you are doing, what is the benefit of a high risk procedure for someone who would not benefit from neurosurgery?
Where is the consideration of the patient wishes and needs in all of this?