Unadjusted clinical and financial outcomesa of 150 patients with methicillin-resistant Staphylococcus aureus surgical site infections (SSI) compared with 231 uninfected controls and 128 patients with methicillin-susceptible S. aureus SSI.

aP values calculated using Student t test or Wilcoxon rank sum test for continuous variables. P-values, odds ratios, and 95% confidence intervals for categorical variables were calculated using the Cochran-Mantel-Haenszel test (MRSA SSI v. matched-uninfected controls) and the Fisher exact test or chi-square (MRSA SSI v MSSA SSI). All percentages were calculated using denominators that excluded missing data.bDenominator includes patients who survived their index admissions.cFinancial data were available for 144 cases (96%), 202 (87%) uninfected controls, and 127 (99%) MSSA SSI controls.