Background: The red blood cell distribution width-to-albumin ratio (RAR) has emerged as a novel indicator of inflammation and nutrition. However, the association between RAR and the risk of stroke remains unclear. This study aims to evaluate the association between RAR and stroke among adults in the United States.

Methods: The study data was acquired from the National Health and Nutrition Examination Survey (NHANES) 2007-2018. Multivariate logistic regression was utilized to analyze the association between RAR and stroke. Restricted cubic spline (RCS) was used to investigate the non-linear relationship between RAR and stroke. Subgroup analysis was conducted to explore the potential interaction. Finally, receiver-operating characteristic (ROC) curve with area under curve (AUC) was used to evaluate the predictive ability of RAR for stroke risk.

Results: A total of 24 658 adult participants was included in the study. The RAR exhibited an independently positive correlation with stroke [OR (95% CI), 1.45 (1.26, 1.66)],
and the correlation was confirmed to be linear by RCS analysis (P for non-linear = .160). Compared to the participants in the lowest quartile of RAR, those in the highest quartile of RAR showed an increased risk of stroke [OR (95% CI), 1.39 (1.06, 1.83)]. Subgroup analysis revealed no significant interactions between stratification variables. Receiver-operating characteristic curve showed an excellent predictive efficacy of RAR for stroke (AUC = 0.829).

Conclusion: There is an independent and positive linear relationship between RAR and stroke among US adults. Further longitudinal research is needed to establish the causality and evaluate clinical relevance of RAR.