Clinical factors and the non-linear relationship between age and neurological outcome in comatose patients following cardiac arrest

Guevara Tirado A. · Revista Espanola de Anestesiologia y Reanimacion (2026) · DOI: 10.1016/j.redar.2026.502233

Resumen

Introduction: Age is often incorporated as a linear or categorical predictor after cardiac arrest, which may obscure variations in its association with neurological outcome. Objective: To evaluate clinical factors associated with good neurological outcome and explore its nonlinear relationship with age in comatose patients after return of spontaneous circulation. Materials and method: Retrospective analysis of 508 patients from the I-CARE cohort. The outcome was Cerebral Performance Category (CPC) 1–2 versus CPC 3–5, based on the best CPC recorded between 3 and 6 months. Age was modeled using restricted cubic splines with four knots. Discrimination, calibration, and optimism were assessed using 1,000 bootstrap resamples. Time to return of spontaneous circulation (ROSC), missing in 51.8%, was examined in sensitivity analyses. Results: CPC 1–2 occurred in 38.2%. Age was associated with outcome (χ2 = 29.16; p < 0.001) and showed nonlinearity (χ2 = 7.79; p = 0.020). A shockable rhythm was associated with a higher probability of good outcome (adjusted OR = 6.68; 95% CI: 4.19–10.66). The AUC was 0.775 for the spline model and 0.767 for the linear model, with no significant difference (p = 0.179); the optimism-corrected AUC was 0.764. In multiple imputation, each additional five minutes to ROSC was associated with a lower probability of good outcome (OR = 0.86; 95% CI: 0.77–0.97). Conclusions: Age showed a nonlinear association with neurological outcome, and flexible modeling improved model fit, although not discrimination. Shockable rhythm was the factor most strongly associated with good outcome.

Instituciones: Universidad Científica del Sur