To the Editor:
We read with interest the article by Leligdowicz and colleagues (1) describing associations between source of infection and mortality among patients with septic shock. The authors aptly point out the relevance of their findings to clinical trial design and prognostic scoring systems. We were intrigued by the demonstration that adjusted mortality risk differs widely between different sites of infection during septic shock and wondered whether this finding may help inform the interpretation of recent studies demonstrating declining severe sepsis mortality rates (2–4). For example, if rates of lower-risk septic shock resulting from urinary tract infections are rising over time, whereas rates of higher-risk septic shock caused by bowel ischemia are declining (perhaps because of improvements in cardiovascular prevention), then large improvements in severe sepsis mortality attributed to improved processes of care may partly be explained by changing secular trends in infection sites. Did Leligdowicz and colleagues observe changing incidence of infection sites over the 19-year course of their study?
Footnotes
The authors are supported by grant K01HL116768 from the National Heart, Lung, and Blood Institute (A.J.W.), by grant K07CA138772 from the National Cancer Institute (R.S.W.), and by the Department of Veterans Affairs (R.S.W.).
Author disclosures are available with the text of this letter at www.atsjournals.org.
References
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