Mortality, complication risk, and total charges after the treatment of epidural abscess

Abstract

Background context: The treatment of epidural abscess is known to have a high rate of morbidity. Little is known regarding the risk factors for postoperative complications, mortality, and costs of care.

Purpose: To identify predictors of postsurgical morbidity and mortality, and total charges, associated with epidural abscess.

Study design: Nationwide Inpatient Sample (NIS) from the year 2006 to 2011.

Patient sample: All patients who had epidural abscess and underwent surgery in the NIS were included. Weighting was used to derive a representative sample.

Outcome measures: They included in-hospital mortality, the development of complications, and total charges. A utility for failure to rescue (FTR) was also developed. Failure to rescue was defined as occurring when patients died after sustaining a complication.

Methods: All patients identified as having epidural abscess and receiving surgical intervention were included. Risk factors were assessed in a bivariate fashion with those maintaining p values less than .2 included in the final multivariable models. Independent predictors of outcome were those that maintained significance after inclusion in multivariable regression. Predictors for total charges were evaluated using generalized linear modeling.

Results: The population consisted of 30, 274 individuals. The mean age was 57.4 years (±14.7 years). Sixty-three percent of the population was white and 27% was underinsured. Diabetes was present in 30% and 19% had some degree of paralysis. Three percent of patients died during hospitalization and 26% sustained one or more complications. Mean total charges were $159,782 (range: $4,008-$3,373,410). Significant independent predictors for mortality included age, insurance status, liver disease, paralysis, and renal failure, with age (80 years or more) having the greatest effect (odds ratio 4.0 [95% confidence interval 2.0, 7.9]). Many of these same variables were found to be influential in the development of postoperative complications, major morbidity, and FTR. The number of medical comorbidities, underinsured status, paralysis, and renal failure were factors that influenced charges to an extent greater than 20% of the population mean.

Conclusions: Age, insurance status, paralysis, and medical comorbidities appear to be the predictors of morbidity, mortality, and expense of care. The results of this work highlight the characteristics that may be targeted to reduce charges and improve care for epidural abscess.

Keywords: Epidural abscess; Failure to rescue; Hospital charges; Mortality; Spinal infection; Surgical morbidity.