Risk factors for spinal surgical site infection, Houston, Texas

Abstract

Objective: Because of an increase in the rate of surgical site infections (SSIs) following spinal procedures at the study hospital, we conducted a study to determine risk factors associated with the development of a SSI.

Design: Case-control study.

Setting: A community hospital in Houston, Texas, with more than 500 beds.

Patients: Fifty-five case patients who developed SSI after spinal surgery and 179 control patients who did not develop SSI after spinal surgery.

Methods: We examined patient- and hospital-associated risk factors for SSI by using existing data on patients who underwent spinal operations at the study hospital between December 2003 and August 2005. Multivariable analysis was conducted using logistic regression to determine significant risk factors associated with SSI.

Results: The presence of comorbidities (odds ratio [OR], 3.15 [95% confidence interval (CI), 1.20-8.26]) and surgical duration greater than the population median of 100 minutes (OR, 2.48 [95% CI, 1.12-5.49]) were identified as independent risk factors for SSI. The use of only povidone-iodine for preoperative skin antisepsis was found to be protective (OR, 0.16 [95% CI, 0.06-0.45]). Specific operating room, hospital staff involved in the procedures, workers' compensation status, method of hair removal, smoking status, or incontinence were not statistically significant.

Conclusions: The presence of comorbidities and increased surgical duration are risks for postoperative infection. The use of only povidone-iodine was found to decrease the risk of infection.