National inpatient complications and outcomes after surgery for spinal metastasis from 1993-2002

Background. Information regarding patient outcomes, complications, and mortality after surgery for spinal metastasis has previously been derived from single-institution series. The aim of this study was to report inpatient mortality, complications, and outcomes on a national level. Methods. The National Inpatient Sample (NIS) was utilized to identify 26,233 admissions of surgically managed spinal metastasis in the U.S. from 1993 through 2002. Multivariate analysis was performed to analyze the effects of patient and hospital characteristics on outcomes such as mortality, complications, discharge disposition, and length of stay. Results. The in-hospital mortality rate was 5.6% and the complication rate was 21.9%. Pulmonary (6.7%) and postoperative hemorrhages or hematomas (5.9%) were the most common complications reported. A single postoperative complication increased the mean length of stay (LOS) by 7 days and the mortality rate by 11%. Multivariate analysis showed that complications were more likely in older patients and in patients with 2 or more comorbidities. With patients having no comorbidities as the reference group, 1 comorbidity increased the risk of in-hospital death by almost 4-fold. Mortality was significantly higher in men, in patients who had postoperative complications, and in patients who were operated in the earlier (1993-1997) year group. Conclusions. A national perspective is provided on inpatient complications and outcomes after surgery for spinal metastasis in the U.S. The significant negative effect of postoperative complications on mortality and resource utilization is demonstrated. Furthermore, preoperative comorbidity is identified as an important risk factor and its impact is defined on patient outcomes.