Setting: Emergency Department (ED)
Numerator: ED visits with a presenting complaint of headache with a coincident brain CT study
Denominator: ED visits with a presenting complaint of headache
Exclusions: Patients who are hospitalized (admitted), patients who are transferred to another acute care hospital, patients with a lumbar puncture, diagnosis codes indicative of dizziness, paresthesia, lack of coordination, subarachnoid hemorrhage, or thunderclap.

Clinical guidelines and literature indicate that there is a general consensus that neuroimaging is rarely productive for patients with normal physical and neurological exams and medical histories. Unnecessary CT is costly financially, in false positive interpretation, and in excess radiation. This measure seeks to identify inappropriate practice patterns.

The lifetime prevalence of headache is over 90 percent for men and women, and according to some studies accounts for 16 million physician visits in the U.S. Nearly 75 percent of all Brain CT studies are requested for symptoms of headache in a commercial population. As CT exposes the patient to higher doses of radiation than conventional x-ray and increases their risk of cancer, unnecessary or duplicative studies are sources of both inefficiency and lower quality care. According to a study conducted by Goldstein et al on US Emergency Departments from 1992 to 2001, headaches represent approximately two percent of Emergency Department visits.

Concern over the inappropriate use of CT Imaging in the Emergency setting has been driven by three primary factors: Cost, Radiation Exposure, and False Positive interpretations. In a recent and yet unpublished article reported in "Diagnostic Imaging" magazine, Dr. Joshua Broder, an assistant professor of emergency medicine at the University of North Carolina at Chapel Hill reported on his institution's study of utilization of CT in the ED from 2000 to 2005 and found dramatic growth significantly outpacing their admission trend of 13 percent, a time when the severity of injury and illness changed little according to Dr. Broder.

In the North Carolina study, a total of about 200,000 patients were admitted to the ED in a five-year period. Over 46,000 CT studies were performed on 27,000 of these patients. Researchers found that Head CT had increased by 51 percent in this time period.

Commercial data analysis indicates a wide variation in Emergency Department Computed Tomography use across populations presenting with complaints of chronic headache and syncope and collapse. A recent report in the New England Journal of Medicine raised serious concerns about the use, and overuse, of CT scanning. It is estimated that 62 million scans are performed per year, compared with only 3 million in 1980. The researchers further estimate that a third of those CT scans are entirely unnecessary—many of them now performed by cautious doctors on worried people in the emergency setting. The result is a patient safety issue involving:

• Unnecessary Radiation Exposure
• Unnecessary Contrast exposure
• The danger of "false-positive" findings

The basic clinical evidence/measures follow evidence-based guidelines from medical specialty associations and relevant professional societies including but not limited to the ACR, the AAFP and the National Headache Consortium. An explicit evidence base is available in the literature that describes the clinical appropriateness and yield from Brain CT. The population based value of Brain CT in chronic headache is clearly addressed by the National Headache Consortium.

The guidelines list several findings resulting in higher likelihood of significant intracranial pathology upon neuroimaging:

• abnormal neurological examination;
• headache worsened by Valsalva maneuver;
• causing awakening from sleep;
• new headache in the older population or progressively worsening headache

The guidelines indicate neuroimaging is not usually warranted for patients with migraine and normal neurological examination.

CT is a procedure that must be ordered by a physician in order to be performed. Therefore, there is the distinct opportunity for the physician to not order an unnecessary study, and for the performing physician to ensure that an unneeded study is not undertaken (controllability). The intended audience (health care providers in the ED) will easily understand the results and find them useful in decision-making. The health care provider can use the results to diminish cost without compromising quality of care.

For non acute headaches with no additional findings, there is a recognized clinical benefit that would both lead to improved health or cost/benefit of the appropriate use of brain CT for chronic headache in the ED.

There may be instances where it would be unclear from a claim as to what the nature of the headache was, making it difficult to determine whether or not a scan would be appropriate. Further, the potential for serious diagnostic error exists. The guidelines rely upon the completion of an appropriate history, physical and neurological exam and the experience of the practitioner.

There are few measures that address imaging efficiency that have been developed despite the recent tremendous growth in imaging in the United States. There are no closely related existing measures.

While the measure is intended for the Emergency Department, it may be used in other settings.