Varying Degrees of Diagnostic Discomfort

A guest post by Rory Spiegel (@EMNerd_) who blogs on nihilism and the art of doing nothing at emnerd.com.

I think we can all agree, there is a fair degree of variability in our (dis)comfort with uncertainty.  As illustrated by an article published in this month’s JAMA Internal Medicine, our discomfort in the unknown and its effect on practice variability has never been more obvious than in the management of acute coronary syndrome (ACS). Kyan et al examined just how this variation affected patient care on a hospital based level. Using a prospectively gathered national database of 2,700 hospitals, the authors extracted those patients in whom cardiac ischemia was considered, and examined the number of patients from each hospital surveyed who received non-invasive cardiac imaging. The authors divided the hospitals into quartiles based on the proportion of their patients who underwent non-invasive testing and examined how this variation in testing affected downstream care.

Of the 224 hospitals included in the data, variation of number of patients who underwent non-invasive cardiac imaging ranged from an impressively nihilistic 0.2% to extraordinarily high 55.7%.  The majority of these tests consisted of myocardial perfusion studies (80.4%) and to a lesser extent stress echocardiography (16.6%). Despite its recent hype CTCA was utilized sparingly as an imaging modality (1.2%). Not surprisingly the hospitals with higher rates of non-invasive testing had higher number of hospital admissions, angiographic studies and revascularization procedures. The increased testing and subsequent interventions failed to demonstrate a noticeable effect on patient outcomes. Both the hospitals in the lowest quartile and those in the highest quartile of non-invasive cardiac testing had equivalent readmission rates for acute myocardial infarction within the next 2-months (0.3%).



Unfortunately this study does not tell us which patients if any, should receive further non-invasive testing following a negative ED work up. What is becoming increasingly clear is if you take a cohort of patients, the vast majority of whom, are not experiencing the pathology in question, no amount of further testing will lead to improved negative predictive values. The only thing gained will be the iatrogenic harms caused by the downstream interventions this increased testing will invariably cause. A high price to pay for a salve for our discomfort…

“Hospital Variation in the Use of Noninvasive Cardiac Imaging and Its Association With Downstream Testing, Interventions, and Outcomes” 
http://www.ncbi.nlm.nih.gov/pubmed/24515551