Financial impact of failing to prevent surgical site infections. 
Despite advances in infection-control practices, surgical site infections (SSIs) remain a substantial cause of morbidity, mortality, and increased costs among hospitalized patients.  We used a matched cohort design to compare costs and length of stay for 16 pediatric patients with an SSI with those of 16 matched control patients who had a similar operative procedure during the same time period but in whom an SSI did not develop.  On average, length of stay was increased by 10.6 days (P = .02) and costs were increased by $27,288 (P = .01) for each patient with a potentially preventable SSI.  On the day of the surgical procedure, costs between study patients and matched controls differed by only 1.4%.  By day 3, however, costs were 36% higher for patients with an SSI.  While matching study patients and control patients requires significant time from financial and clinical staff, this approach and the resulting data analysis strengthened and focused our efforts to prevent future SSIs and aligned initiatives to reduce SSIs with the business case for quality.