Diagnostic value of protein S100b as predictor of traumatic intracranial haemorrhage in elderly adults with low-energy falls: results from a retrospective observational study

Purpose The objectives of this study were to analyse the clinical value of protein S100b (S100b) in association with clinical findings and anticoagulation therapy in predicting traumatic intracranial haemorrhage (tICH) and unfavourable outcomes in elderly individuals with low-energy falls (LEF). Methods We conducted a retrospective study in the emergency department (ED) of the LMU University Hospital, Munich by consecutively including all patients aged ≥ 65 years presenting to the ED following a LEF between September 2014 and December 2016 and receiving an emergency cranial computed tomography (cCT) examination. Primary endpoint was the prevalence of tICH. Multivariate logistic regression models and receiver operating characteristics were used to measure the association between clinical findings, anticoagulation therapy and S100b and tICH. Results We included 2687 patients, median age was 81 years (60.4% women). Prevalence of tICH was 6.7% (180/2687) and in-hospital mortality was 6.1% (11/180). Skull fractures were highly associated with tICH (odds ratio OR 46.3; 95% confidence interval CI 19.3–123.8, p < 0.001). Neither anticoagulation therapy nor S100b values were significantly associated with tICH (OR 1.14; 95% CI 0.71–1.86; OR 1.08; 95% CI 0.90–1.25, respectively). Sensitivity of S100b (cut-off: 0.1 ng/ml) was 91.6% (CI 95% 85.1–95.9), specificity was 17.8% (CI 95% 16–19.6), and the area under the curve value was 0.59 (95% CI 0.54 − 0.64) for predicting tICH. Conclusion In conclusion, under real ED conditions, neither clinical findings nor protein S100b concentrations or presence of anticoagulation therapy was sufficient to decide with certainty whether a cCT scan can be bypassed in elderly patients with LEF. Further prospective validation is required.