Frederick K. Korley M.D.

1. The potential impact of adherence to a guideline on the utilization of head CT scans in traumatic head injury patients. Frederick K. Korley M.D.

2. Background (1) • 2001 Institute of Medicine report “Crossing the quality chasm” reported “uneven” adherence to well established evidence by clinicians (IOM report 2001) • Barriers to adherence: lack of awareness, inadequate familiarity, variable agreement, questioning of self-efficacy and outcome, and inertia (Cabana et al, JAMA 1999). • Example of potential gap between evidence and practice: Utilization of head CT scans in traumatic head injury.

3. Background (2) • Over 1 million patients present to EDs annually for traumatic head injury(Guerrero et al, Brain Inj 2000). • > 70% get head CT scans (Stiell et al, Lancet 2001). • Important findings < 20% (Atzema, Ann E Med 2004). • Unnecessary CT scans are at an enormous cost (health care expenditure, exposure to ionizing radiation, ED length of stay). • 2008: American College of Emergency Physicians (ACEP) developed a clinical policy on CT utilization in head injury cases using best available evidence.

4. National trends for CT scan utilization in all injury-related illness1 Korley FK, Pham JC, Kirsch TK. The use of advanced imaging in Emergency Department patients with injury-related complaints 1998-2007. Submitted for publication.

5. Knowledge gap • Baseline level of adherence of routine ED practice to ACEP guidelines unknown. • Potential impact of the ACEP policy on safe reduction of head CT scans in traumatic head injury unknown.

6. Hypothesis • If adhered to, the ACEP clinical policy would result in a 10% or more decrease in the proportion of patients receiving head CT scans. • Further, this would not result in missing patients with acute traumatic findings.

7. Study Population • Patients presenting to the Adult Johns Hopkins Hospital ED with traumatic head injury. • Inclusion: Age > 18 years; time of injury < 24 hours from ED presentation. • Exclusion: Unstable vital signs; victims of stabbing or gunshot wound; obvious depressed skull fracture; initial ED GCS < 15; seizure event after traumatic episode; pregnant; return reassessment for the same head injury.

8. Methods • Subject enrollment: Assess all ED patients for eligibility. Prospectively, continuously enroll patients meeting eligibility criteria. • Primary outcome: Difference between actual and ACEP recommended head CT scans. • Secondary outcomes: • % encounters where physician followed ACEP policy • Among patients in whom CT would have not been recommended: • % with acute findings on CT (defined by Haydel et al, NEJM 2000) • % needing neurosurgical intervention by 14 days

9. Data collection • Interview in the ED: patient history, baseline characteristics. Chart review for exam findings. Categorize patients based on ACEP policy. • Chart reviewed at 14 days: determine if a head CT scan was obtained, and whether patient needed a neurosurgical intervention. • A physician masked to patient characteristics and exam findings will review CT scan reports and classify them on the presence of acute traumatic finding.

10. Sample size and feasibility • 190 patients needed to have 90% power to detect a 10% or greater change in the proportion of patients with no acute traumatic CT scan finding (alpha=0.05, two tailed). • 90 eligible patients per month • 3 month enrollment period

11. Data analysis • Chi-square test to determine difference between % of actual and ACEP recommended head CT scans. • Descriptive statistics to determine • % encounters where physician followed ACEP policy • % with acute findings on CT • % needing neurosurgical intervention by 14 days

12. Limitations

13. Significance • Results will help establish the current level of adherence to the ACEP policy and the potential impact of adherence. • Use as baseline data to assess effectiveness of a future intervention to implement this policy.