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Powers of Observation

Farhood Farjah, MD; David R. Flum, MD, MPH

JAMA. 2007;297:2525-2526.

	Since this article does not have an abstract, we have provided the first 150 words of the full text and any section headings.

In this issue of JAMA, Wu and colleagues¹ report the results of a cohort study examining the relationship between preoperative hematocrit levels and adverse events among older veterans (most of whom were men) undergoing noncardiac surgery. Incremental departures less than or greater than normal hematocrit levels for mostly men were associated with increased risk of early death and postoperative cardiac events. The authors recommend future studies to evaluate interventions aimed at reducing the risk of postsurgical events attributable to either anemia or polycythemia.

This work highlights the strengths of using high-quality, large observational databases—such as the Veterans Affairs (VA) National Surgical Quality Improvement Program (NSQIP)—to explore the relationship between patient factors and adverse outcomes. A large sample size allowed for adjustment of many potentially confounding variables that are common to surgical practice. Moreover, the sample size augments natural strengths of a . . . [Full Text of this Article]

Author Affiliations: Department of Surgery, University of Washington, Seattle. Dr Flum is Contributing Editor, JAMA.