Keeping It Simple: Developing a Prognostic Tool for Spinal Epidural Abscess

Abstract

Study Design A retrospective study. Objective To develop a prognostic score for mortality and treatment failure in Spinal epidural abscess (SEA), based on simplicity and multidimensional assessment principles. Methods One-hundred-fifty patients were reviewed. Variables assessed included comorbidities, functional status, clinical presentation, Frankel classification, and biochemical and radiological parameters. The main outcomes were the 90-day mortality and treatment failure, corresponding to any intensification of the initial treatment plan. Variables were sorted out with a factorial analysis. Logistic regressions were performed, and the new score was derived from the coefficients. ROC curves with Area Under Curve, calibration plots, and cross-validation were performed. Results Forty-three patients (29%) had treatment failure, and 15 died (10%) by 90 days. Factorization created 3 groups: C omorbidities (C), S everity (S), and F unction (F). For 90-day mortality, Odds ratios were 1.20 ( P = .0002), 1.15, ( P = .03), 1.36, ( P < 10−4) for C, S, F, respectively. The new score ‘ CSF’ had 1 point per item, ranging from zero to 3. OR increased by 1.2/point for 90-day mortality ( P < 10−4), AUC was .86. For failures OR increased by 1.15/point ( P = .014), AUC was .58, and increased to .64 for patients who survived after 90 days, probably due to competing risks. Conclusions Comorbidities, Severity, and Function is a new simplistic tool, easy to use in daily practice; its performances were excellent for 90-day mortality, and acceptable for failures. Simple tools are more likely to be adopted into practice. External validation of this technique is desirable.