Posted by Sten Westgard, MS
We've all heard the infamous quote now over a decade and a half old: that US hospitals kill between roughly 40,000 and 90,000 patients each year. This was an estimate courtesy of the Institute of Medicine report "To Err Is Human" which made the dire performance of hospitals knowledge that even the general public could understand.
But more recently, studies have been tracking the adverse event rates much more closely. A recent NEJM paper followed four conditions from 2005 to 2011.
Of these four conditions, which do you think has the best Sigma performance when it comes to the occurrence of adverse events?
A. Acute Myocardial Infarction (AMI)
B. Congestive Heart Failure
D. (other) Conditions Requiring Surgery
The answer, after the jump...
The answer, as it turns out, is that it's almost a tie between A,C, and D. Pneumonia, AMI, and Conditions Requiring Surgery all have the same Sigma rate, while Congestive Heart Failure (answer B) is only slightly higher.
Here are the full answers:
|Condition||Overall event Error Rate||Sigma metric|
|Acute Myocardial Infarction (AMI)||3.5%||3.3|
|Congestive Heart Failure||2.8%||3.4|
|Conditions Requiring Surgery||3.3%||3.3|
In the world of Six Sigma, the threshold of 3 Sigma is considered the floor, the lowest level of performance considered acceptable for an efficient, profitable, and effective process. So while this news on adverse events is at least not terrible, it's still depressing - this is where we are after over a decade of focus and effort on patient safety? While the adverse event rate has declined for AMI and Congestive Heart Failure has declined over the course of 6 years, the adverse event rates for Pneumonia and (other) Conditions Requiring Surgery have had no significant decline at all. We haven't made any progress there.
The study is here:
National Trends in Patient Safety for Four Common Conditions, 2005-2011, Wang Y, Eldridge N, Metersky ML et al, NEJM (2014)370;4:341-351