Can 'noisy data' perform as well as 'clean data' in outcome modeling after aneurysmal subarachnoid haemorrhage?

Baroreflex sensitivity (BRS) is associated with clinical outcome in patients with aneurysmal subarachnoid haemorrhage (aSAH); however few studies have investigated this in typical clinical settings. This two-centre study evaluated how outcome models differ when excluding patients who received beta-blockers and/or noradrenaline ('clean data' set) versus including all of them ('noisy data' set).

This retrospective study included consecutive aSAH patients from Addenbrooke's Hospital (UK) and Wroclaw Medical University (Poland). Early BRS was measured using the cross-correlation method. A favorable outcome was defined as a Glasgow Outcome Scale (GOS) score of 4-5 at discharge.

A total of 108 patients were included, with 40 receiving beta-blockers and/or noradrenaline. The median age was 56 (IQR ± 17) years old, where 73 % were women. On admission, 57 % had a Glasgow Coma Scale (GCS) score of 13-15. Univariate logistic regression showed BRS was significantly associated with outcome in both the 'clean data' set (OR 1.16, 95%CI [1.02,1.30]) and 'noisy data' set (OR 1.10, 95%CI [1.03,1.18]). In multivariate analysis, the best 'clean data' model (χ² = 22.89, p < 0.001, AUC = 0.88) included heart rate (HR) (OR 0.93, 95%CI [0.87,0.99]) and GCS (OR 1.38, 95%CI [1.12,1.69]). The best 'noisy data' model (χ² = 32.27; p < 0.001, AUC = 0.84) included BRS (OR 1.10, 95%CI [1.01,1.20]) and GCS (OR 1.32, 95%CI [1.16,1.51]).

Early BRS was independently associated with short-term outcome after aSAH, regardless of beta-blockers or noradrenaline use. In the 'clean data' set, HR was significantly associated with outcome, whilst in the 'noisy data' set, BRS was significantly associated with outcome. A larger multicentre study is required to validate these findings.