Surgical site infection: Incidence and impact on hospital utilization and treatment costs

Background: Surgical site infections (SSIs) are serious operative complications that occur in approximately 2% of surgical procedures and account for some 20% of health care-associated infections. Methods: SSI was identified based on the presence of ICD-9-CM diagnosis code 998.59 in hospital discharge records for 7 categories of surgical procedures: neurological; cardiovascular; colorectal; skin, subcutaneous tissue, and breast; gastrointestinal; orthopedic; and obstetric and gynecologic. Source of data was the 2005 Healthcare Cost and Utilization Project National Inpatient Sample (HCUP NIS). Primary study outcomes were rate of SSI by surgical category and impact of SSI on length of stay and cost. Results were projected to the national level. Results: Among 723,490 surgical hospitalizations in the sample, 6891 cases of SSI were identified (1%). On average, SSI extended length of stay by 9.7 days while increasing cost by $20,842 per admission. From the national perspective, these cases of SSI were associated with an additional 406,730 hospital-days and hospital costs exceeding $900 million. An additional 91,613 readmissions for treatment of SSI accounted for a further 521,933 days of care at a cost of nearly $700 million. Conclusion: SSI is associated with a significant economic burden in terms of extended length of stay and increased costs of treatment. Our analysis documented nearly 1 million additional inpatient-days and $1.6 billion in excess costs.