The Prognostic Value of Laboratory Markers and Ambulatory Function at Presentation for Post-Treatment Morbidity and Mortality Following Epidural Abscess.

Study Design: Retrospective cohort study.
Objective: To develop a comprehensive understanding of the prognostic value of laboratory markers on morbidity and mortality following epidural abscess.
Summary of Background Data: Spinal epidural abscess is a serious medical condition with high rates of morbidity. The value of laboratory data in forecasting morbidity and mortality after epidural abscess remains underexplored.
Methods: We obtained clinical data on patients treated for epidural abscess at two academic centers from 2005 to 2017. Our primary outcome was the development of one or more complications within 90-days of presentation, with mortality a secondary measure. Primary predictors included serum albumin, serum creatinine, platelet-lymphocyte ratio, and ambulatory status at presentation. We used multivariable logistic regression techniques to adjust for confounders. The most parsimonious set of variables influencing both complications and mortality were considered to be clinically significant. These were then examined individually and in combination to assess for synergy along with model-discrimination and calibration. We performed internal validation with a bootstrap procedure using sampling with replacement.
Results: We included 449 patients in this analysis. Complications were encountered in 164 cases (37%). Mortality within 1-year occurred in 39 patients (9%). Regression testing determined that serum albumin, serum creatinine, and ambulatory status at presentation were clinically important predictors of outcome, with albumin more than 3.5 g/dL, creatinine less than or equal to 1.2 mg/dL, and independent ambulatory function at presentation considered favorable characteristics. Patients with no favorable findings had increased likelihood of 90-day complications (odds ratio [OR] 5.43; 95% confidence intervals [CI] 1.98, 14.93) and 1-year mortality (OR 8.94; 95% CI 2.03, 39.37). Those with one favorable characteristic had greater odds of complications (OR 4.00; 95% CI 2.05, 7.81) and mortality (OR 5.71; 95% CI 1.60, 20.43).
Conclusion: We developed a nomogram incorporating clinical and laboratory values to prognosticate outcomes after treatment for epidural abscess. The results can be used in shared-decision making and counseling.
Level of Evidence: 3.