The bean counters are missing some beans

There is a recently released report from the Society of Actuaries entitled the Economic Measurement of Medical Errors. It's nearly 300 pages long and includes data on catheter-associated UTI, central line associated bloodstream infection, and surgical site infections. It is based entirely on administrative claims data, which are notoriously inaccurate for healthcare-associated infections. See Kurt Stevenson's paper on this topic here.

As I looked through the report, I noted that the numbers looked quite odd based on my familiarity with the literature. So I compared the SOA report data to CDC's estimates on the burden of HAIs in the US (Klevens et al) and Eli's review of the literature on attributable cost in the table below.

	Estimated annual number of cases		Attributable cost/case
	SOA Report	CDC	SOA Report	Perencevich
CA-UTI	9,080	561,667	$32,820	$1,257
CLABSI	3,679	248,678	$110,462	$18,462

Now there a number of caveats to point out:

• The SOA reports the estimated number of cases due to error; to convert from number of cases to cases due to error they multiplied the number of cases by 0.95. Therefore, I divided the "error" cases by 0.95 to convert back to number of cases (Does anyone believe that 95% of CA-UTI cases are due to error, that is, preventable???)
• Eli used 2005 dollars for cost data, and SOA used 2008
• SOA used 2008 claims data, and CDC (Klevens et al) used 1990-2002 NNIS data and National Hospital Discharge Survey 2002 data
• CDC data appear to included non-device associated infections, though we know that the vast majority of UTIs and BSIs are device related

However, despite the differences I note, the SOA data seem hugely flawed. They appear to vastly underestimate the frequency of HAIs, while substantially overestimating the attributable costs. I suspect the SOA report will be widely quoted, so take a look at it and be prepared!