Please report problems to scott-sherman@uiowa.edu


Note: The calculator requires that javascript be enabled in your browser.

The calculator requires numerical entries for White Count, Age, and Hematocrit to work.

The risk model applies only to patients over 18 years of age and excludes patients undergoing emergency procedures.

The model was updated in 2017 to include low anterior resections (LAR). Both the Original and Updated Iowa Rectal Surgery Risk Calculators remain available.

Both calculators are based on 2010-11 NSQIP rectal surgery data. The Original Calculator was based on an analysis of 5,570 patients who had surgery in 2010 and 2011 and excluded LAR. The calculator was validated on 7,815 patients who had surgery in 2005-2009.

Further work in 2017 updated the calculator to include LAR and performed a prospective validation for both the Original and Updated Calculators using 2012-15 NSQIP data (51,344 patients).

Please note that although the calculator provides valid risk estimates in aggregate, its prediction for any individual patient is an estimate only, and must be interpreted in light of the overall clinical picture with the judgement of an experienced surgeon.  

Go to Updated Iowa Rectal Surgery Risk Calculator

Go to Original Iowa Rectal Surgery Risk Calculator