Danger Of Using Case Studies To Dictate Imaging Policy: The Initial Covid-19 Study
Rumors abounded at the beginning of March 2020 about Covid-19. And, no one quite knew how Covid-19 would play out. All sorts of physicians were on edge to try to figure out what to do. But then a new case study about the role of CT scan arrived at the scene. And, clinicians began to read or hear about this “seminal paper” in Radiology that came out from China, called Correlation of Chest CT and RT-PCR Testing in Coronavirus Disease 2019 (COVID-19) in China: A Report of 1014 Cases. This paper claimed a high sensitivity for the detection of the diagnosis coronavirus compared to PCR. Admitting physicians quoted it and demanded to get CT scans on their patients with presumed Covid-19. ER doctors were ordering Chest CT scans left and right.
What happened next? The throughput of patients slowed down to a crawl because the CT scanner needed special cleaning for potential Covid-19 contamination. Subsequently, this thorough cleaning delayed the treatment of patients. And, the CT scanner was out of commission for other patients that needed the CT scan for emergency workups.
Was it the right to use this paper to dictate the workup of patients? In hindsight, no. And, it brings up an all too common issue, the usage of case studies to dictate health care policy. So, what are the other factors that we need to evaluate before we decide to take a paper and apply it to patient care? Well, I will use this incident as a way to show you what you need to think about before using case studies to guide patient imaging. Let’s divide it into the following categories: practicality, throughput, exposure, and change in management.
Practicality- It’s Not All About Sensitivity Or Specificity
I don’t know about you. But, whenever I hear a test is highly sensitive or specific for a disease entity, I get excited. My first thought is usually, maybe we can use this exam to diagnosis patients? However, before arriving at that conclusion, we need to take a step back. Does the test make sense in the context of patients coming into the emergency department? Many clinicians did not think about these issues when they decided to utilize a CT scan to image presumptive Covid-19 patients. Just because you can make a diagnosis does not mean that you should complete a test.
Throughput is Important
A test is only useful when it can rapidly diagnose patients. In the case of CT scans for the diagnosis of Covid-19 patients, regardless of any other factor, our throughput for patient care significantly slowed down. And, this had a dramatic effect upon the patients that came into the Emergency Department for many other reasons. Always, physicians need to take this factor into account before jumping into ordering a test.
Exposure To Health Care Workers And Patients
We need to take care of all the folks that are providing services for the sick and infirm. If we do not perform this duty, we will have no health care workers to treat patients. In this situation, deep cleaning the CT scanner after each patient added undue risk to the technologists and nurses that completed these functions. Not to mention, you are also increasing the possibility of exposure to the next patient in the CT scanner. The upshot was a tremendous cost to the patients and employees.
Does It Change Management?
And, then finally, the most critical question that we need to ask ourselves is how does the test change management? In the case of Covid-19, a negative test did not preclude the possibility of the disease. So, regardless of the test outcome, the clinicians would need to use their clinical intuition to decide if they need to ventilate the patient or other invasive measures. Moreover, the treatment of the patient would remain the same, whether the CT was positive or negative. Why submit a patient to such a test?
Beware The Dangers of Using Small Case Studies To Dictate Policy!
We all need to take a step back when we hear the claims of physicians that we should be imaging a patient based on a paper. Instead, you should be answering the following questions: Is it practical? Will it prevent other patients from receiving appropriate testing? Will it endanger my staff and patients? And, does it change the management of the patient’s case? If the case studies can pass these tests, consider using it as a tool. If not, beware of imaging the patient based on a paper, the test may do more harm than good!