Dr. Christopher Buckle, National Medical Director, Radiology and Guideline Development, AIM Specialty Health
Advances in radiology have transformed the diagnosis and management of medical diseases across the care continuum. Lung cancer screening for high risk patients, early diagnosis of multiple sclerosis, staging and therapy response in lymphoma, aneurysm surveillance are just a few examples of the way imaging has led to earlier and more accurate diagnosis or created more sophisticated ways to plan treatment or assess response.
"Clinical guidelines, when developed within a framework of appropriateness, are an excellent starting point to synthesize medical research and real world practice to facilitate the delivery of appropriate, safe and affordable care"
But with new opportunities come new challenges. What is the significance of an incidental finding? What are the consequences of false positive studies that lead to unnecessary anxiety, testing and potentially treatment? What harms – direct or indirect – occur when patients are tested too frequently?
Appropriate use programs like prior authorization or clinical decision support seek to balance the benefits and harms of advanced diagnostic testing. Many appropriate use criteria for advanced imaging have been developed by a variety of government agencies, specialty societies, providers and payers alike.
But what does appropriate use even mean? There is a wide range. For some, appropriate use occurs only when there is high quality evidence showing that the test improves the outcome of patients. For others, any study that experts deem appropriate suffices as a definition.
At AIM Specialty Health, we believe it is important to have a transparent definition or framework of appropriate use applied consistently across imaging requests. While that might seem daunting given the sheer breadth and complexity of modern imaging requests, we have seen consistent themes emerge across a diverse array of imaging guideline developers that appropriate use requires a few key principles:
• Reasonable likelihood of disease
• Optimal diagnostic testing strategy
• Impact on management and/or outcome
Reasonable likelihood of disease
Prior to any intervention, it is essential that the clinician confirm the diagnosis or establish its pretest likelihood based on a complete evaluation of the patient. Imaging is especially helpful to confirm or exclude a diagnosis in patients with moderate to high clinical suspicion, but may not always be indicated in patients with a low or very low likelihood of disease. For example, the likelihood that an otherwise healthy patient with a migraine and a normal neurological exam will have a cause for their headache discovered on MRI is very low and no greater than the likelihood that a patient without any symptoms will have one present.
Optimal diagnostic testing strategy
Often there are several tests that can help to establish a diagnosis, each of which has advantages and drawbacks. A testing strategy defines when one test should occur before or after the other and is based on an assessment of both the benefits (increased diagnostic accuracy) and the risks. For example, a chest x-ray has good diagnostic accuracy and results in much less radiation exposure that a chest CT so should generally be performed first.
Impact on management or outcome
The results of the diagnostic test should provide information that allows the clinician to make a decision, impacting how the patient will be treated or not treated as the case may be. Ideally, this impact on treatment should improve the outcome of the patient. For instance, if a patient with back pain is going to be initially treated with physical therapy, imaging to confirm the presence of a disc herniation is unlikely to change the treatment plan. However if physical therapy or other conservative measures have failed to improve their pain, imaging is very helpful to determine the need for and type of surgery. In addition, adherence to guidelines has been tied to better outcomes.
An appropriateness framework allows for the consideration of unique patient circumstances during the peer-to-peer review. Hence, clinical guidelines, when developed within a framework of appropriateness, are an excellent starting point to synthesize medical research and real world practice to facilitate the delivery of appropriate, safe and affordable care.