What’s New in the Patient Safety World

September 2017


Clinical Decision Rule Success



Use of clinical decision rules can have multiple advantages for hospitals, emergency departments, payers, and patients. For example, use of any of the several clinical decision rules for CT scanning in cases of minor head trauma may reduce the number of unnecessary CT scans, reduce ED throughput times, reduce hospital costs, and even reduce costs of the “diagnostic cascade” that follow discovery of incidental findings.


In our March 2017 What's New in the Patient Safety World column “Update on CT Scanning after Minor Head Trauma” we pointed out that there’s no shortage of clinical decision rules guiding the ordering of CT scans in patients with minor head trauma. We have the Canadian CT Head Rule (Stiell 2001), the New Orleans Head CT Rule (Haydel 2000), and the NICE guideline (NICE 2014) in adults. And for children we have CHIP (Smits 2007), CATCH (Osmond 2010), and the NICE guideline (NICE 2014).


Perhaps the most frequently used clinical decision rule is the Canadian CT Head Rule (CCHR). In that previous column we noted a study which looked at the appropriateness of head CT scans for minor head trauma using the CCHR as the guideline (Klang 2017). The authors retrospective reviewed 955 head CT scans and found 10.9% were not indicated according to the CCHR. And, for patients under the age of 65, 37.3% of scans ordered were not indicated according to that rule. The authors suggested that interventions to reduce the frequency of non-indicated head CT scanning might include targeted education of staff members, protocol implementation, and implementation of computerized decision rules.


Well, clinicians at Kaiser Permanente did just that. First, clinicians and researchers did an electronic health record (EHR) database and chart review of adult ED trauma encounters receiving a head CT from 2008 to 2013 (Sharp 2017a). They found that about one-third of head CTs performed on adults with head injury might be avoidable by applying the CCHR and that avoidance of CT in such patients is unlikely to miss any important injuries. Then they implemented the CCHR protocol in 13 Southern California ED’s using a multicomponent intervention included clinical leadership endorsement, physician education, and integrated clinical decision support (Sharp 2017b). Overall, they noted a 5.3 percent reduction in CT use and an increase in CT-identified injuries. Twelve of the 13 emergency departments reduced head CT following the implementation of the intervention.


Though the reduction in CT scans was more modest than they would have predicted, it certainly is a start in the right direction. Keys to success were likely the buy-in of clinical leaders, pilot testing, physician education through an e-learning module, and integration of the protocol into the electronic medical record (Kaiser Permanente 2017).



Some of our previous columns on CT scans in minor head trauma:


April 16, 2007 “Falls With Injury

July 17, 2007  Falls in Patients on Coumadin or Heparin or Other Anticoagulants

March 2010     CATCH: New Clinical Decision Rule for CT in Pediatric Head Trauma

November 23, 2010 “Focus on Cumulative Radiation Exposure

June 5, 2012    Minor Head Trauma in the Anticoagulated Patient”.

July 8, 2014     Update: Minor Head Trauma in the Anticoagulated Patient

January 2017   Still Too Many CT Scans for Pediatric Appendicitis

March 2017     Update on CT Scanning after Minor Head Trauma







Stiell IG, Wells GA, Vandemheen K, et al for the CCC Study Group. The Canadian CT Head Rule for patients with minor head injury. Lancet 2001; 357: 1391–96




Haydel MJ, Preston CA, Mills TJ, et al. Indications for Computed Tomography in Patients with Minor Head Injury. N Engl J Med 2000; 343: 100-5 (New Orleans Head CT Rule)




NICE (UK National Institute for Health and Care Excellence). Head injury: assessment and early management. Clinical guideline [CG176] Published date: January 2014


NICE imaging algorithm




Smits M, Dippel DWJ, Steyerberg EW, et al. Predicting Intracranial Traumatic Findings on Computed Tomography in Patients with Minor Head Injury: The CHIP Prediction Rule. Ann Intern Med. 2007; 146: 397-405




Osmond MH, Klassen TP, Wells GA, et al. CATCH: a clinical decision rule for the use of computed tomography in children with minor head injury. Can. Med. Assoc. J., Feb 2010; early release published February 8, 2010 doi:10.1503/cmaj.091421




Klang E, Beytelman A, Greenberg D, et al. Overuse of Head CT Examinations for the Investigation of Minor Head Trauma: Analysis of Contributing Factors. J Amer Coll Rad 2017; 14(2): 171-176 Published online: November 8, 201




Sharp AL, Nagaraj G, Rippberger EJ, et al. Computed Tomography Use for Adults With Head Injury: Describing Likely Avoidable Emergency Department Imaging Based on the Canadian CT Head Rule. Academic Emergency Medicine 2017; 24: 22-30 First published online January 12, 2017




Sharp AL, Huang BZ, Tang T, et al. Implementation of the Canadian CT Head Rule and Its Association With Use of Computed Tomography Among Patients With Head Injury.

Ann Emerg Med 2017; Published online: July 21, 2017




Kaiser Permanente. Kaiser Permanente Emergency Department Intervention for Adult Head Trauma Reduces CT Use. Press Release July 21, 2017







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