Introduction: Postoperative spinal wound infections are a significant cause of increased patient mortality, complication rate, and health care costs. However, due to the rarity of its occurrence, it is difficult to assess risk factors of postoperative infection with significant power when using smaller, single-institution patient series.
Methods: We used the MarketScan database from 2006 to 2010 to select for 295,182 patients undergoing cervical, thoracic, or lumbar spine procedures based on CPT coding at inpatient visit. Primary outcome measures of 30-day postoperative infection status were ascertained using ICD9 coding. Secondary outcomes including total length of hospital stay, complication rate, readmission rate, return to OR rate, and total payments were obtained from variables within the MarketScan database.
Results: Overall, lumbar procedures were most susceptible to deep wound infections, while thoracic procedures were most susceptible to sepsis. In all three cohorts, postoperative wound infection patients had statistically significant longer lengths of stay (p<.0001), higher 30-day non-infectious complication rates (p<.0001), higher 30-day readmission rates (p<.0001), and higher 30-day return to OR rates (p<.005). These cases resulted in both statistically significant increases in hospital and overall case payments (p<.0001), but not in physician payments. In a multivariate analysis, risk factors for infection in the cervical cohort included non-instrumentation, tobacco use, metastatic cancer, and diabetes. Risk factors for infection in the thoracic cohort included instrumentation and non-metastatic cancer. Risk factors for infection in the lumbar cohort included instrumentation, obesity, diabetes, coagulation disorders, metastatic cancer, preoperative weight loss, tobacco use, renal disease, hypertension, and alcohol use.
Conclusions: In this study, we report postoperative infection rates and associated patient comorbidity risk factors. The negative impact of postoperative infection on inpatient length of stay, complication rates, and return to OR rates present a significant hospital resource burden and warrant increased focus on infection risk mitigation, especially for patients with comorbid conditions.
Patient Care: This is one of the largest studies examining risk factors for postoperative wound infection after spinal surgery. Using multivariate analysis of the Marketscan database, we have validated a number of the most important preoperative risk factors for increased postoperative spinal wound infection. The information provided should assist clinicians in recognizing pertinent risk factors and allow for the improved mitigation of possible infections through better informed care for high-risk patients.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of post-surgical wound infection in hospital resource management. 2) Discuss, in small groups, the pertinent risk factors associated with increased post-surgical infection. 3) Identify possible effective treatment strategies for the improved mitigation of infections.