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

Abstract

A retrospective study. To develop a prognostic score for mortality and treatment failure in Spinal epidural abscess (SEA), based on simplicity and multidimensional assessment principles. 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. Forty-three patients (29%) had treatment failure, and 15 died (10%) by 90 days. Factorization created 3 groups: <b><i>C</i></b><i>omorbidities (C)</i>, <b><i>S</i></b><i>everity (S),</i> and <b><i>F</i></b><i>unction (F)</i>. For 90-day mortality, Odds ratios were 1.20 (<i>P</i> = .0002), 1.15, (<i>P</i> = .03), 1.36, (<i>P</i> < 10^-4) for <i>C, S, F</i>, respectively. The new score '<i>CSF'</i> had 1 point per item, ranging from zero to 3. OR increased by 1.2/point for 90-day mortality (<i>P</i> < 10^-4), AUC was .86. For failures OR increased by 1.15/point (<i>P</i> = .014), AUC was .58, and increased to .64 for patients who survived after 90 days, probably due to competing risks. <i>Comorbidities</i>, <i>Severity</i>, and <i>Function</i> 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.