Harder! Better! Faster! Stronger! There is a proliferation of time-based measures in the Emergency Department – the glut of which funds a horde of administrative overhead, and for which the Center for Medicare and Medicaid Services will audit. These measures must frequently seem relatively benign and commonsense when conceived – but their implementation is anything but.
This is a retrospective quality evaluation from the Christiana Health System, looking at their door-to-balloon time metric for STEMI. Faster is better – of course – so, in 2009, an aggressive quality improvement intervention was performed to decrease delays and obstacles to cardiac catheterization. As described in the article, this mostly seemed to consist of exhorting each step the process to be performed more rapidly, and providing additional feedback during the QI initiative.
And, it worked! Median door-to-ballon time sank from 76 minutes to 61 minutes by 2010.
Unfortunately, this came at a cost: false-positive activations more than doubled. Furthermore, the mortality rate of false-positive activations jumped from 5.6% to 21.6%. The fatal alternative diagnoses included massive PE, intracranial hemorrhage, severe sepsis, and aortic dissection.
The authors go on further to describe a follow-up QI intervention of education and feedback regarding the missed diagnoses, and, over time, the mortality rate has improved. However, false positives persist around 20% of activations – triple the original rate.
So, they’ve saved 15 minutes of door-to-balloon time – a probably clinically insignificant amount – at the cost of scads new false-positives and at least one substantial bump in mortality. And, you know this is but _one_ of many time-based metrics invading – and harming patients in – the Emergency Department.
Will the madness ever stop?
“Aggressive Measures to Decrease “Door to Balloon” Time and Incidence of Unnecessary Cardiac Catheterization: Potential Risks and Role of Quality Improvement”
http://www.ncbi.nlm.nih.gov/pubmed/26549506
I'm always skeptical when FP rates for STEMI systems are less than 10-15%, probably a lot of vulnerable myocardium left out there…but that hinges on their definition of "false positive", something not exactly perfect in most systems.
I'm left wondering how PE, ICH, and sepsis made it into STEMI activations given that they don't typically present with ST-e localized to a wall/artery (perhaps they're activating on undifferentiated subendocardial ischemia, popularized by ST-e in aVR w/ widespread ST-d).
Aortic dissections I'm familiar with as a "mimic", as they can manifest with localized ST-e and instead must be differentiated by non-ECG findings. Makes sense that speeding up cuts out time for that differentiation.
It does go to show the inevitable, that when you pick a metric to optimize against your system will work to that metric whether it is right, wrong, or indifferent and you'll enjoy the consequences of that optimization. (I think the authors should be commended for studying the effect on their patients after making a system level change)
FWIW, their false-positive rate started at 6-7% – and then went to 20% after the intervention. And, few STEMIs present in the hyperacute window where 15 minutes changes much – most have had longer symptom duration.
But, yes, I think the misdiagnoses are simply part of a culture of "if it looks questionable, activate" – let the patient suffer, not the metrics.
I feel like this paper should be subtitled "How we created a well-intentioned but poorly executed QI initiative that ended up hurting our patients, so we did a second one to fix the first."