Hemoglobin levels and cognitive trajectory: unveiling prognostic insights in post-stroke geriatric cohort

Evidence is scarce regarding the association between anemia and alterations in cognitive level among hospitalized older patients. We aimed to evaluate the associations between baseline hemoglobin (Hb) levels and changes in cognitive level in patients undergoing rehabilitation after stroke.

A retrospective cohort study was conducted, encompassing consecutively hospitalized post-stroke patients. Data on serum Hb levels were extracted from medical records, specifically tests conducted within 24 hours of admission. Primary outcomes included discharge scores for cognitive function assessed by the cognitive domain of the Functional Independence Measure (FIM-cognition) and the corresponding change in FIM-cognition during hospitalization. Another outcome measure was the length of hospital stay. Multivariate linear regression analyses were employed to assess the association between Hb levels at admission and the designated outcomes, adjusting for potential confounding factors.

Data from 955 patients (mean age 73.2 years; 53.6% men) were included in the analysis. The median Hb level at admission was 13.3 [11.9, 14.5] g/dL. After fully adjusting for confounding factors, the baseline Hb level was significantly and positively associated with FIM-cognition at discharge (β = 0.045, p = 0.025) and its gain (β = 0.073, p = 0.025). Further, the baseline Hb level was independently and negatively associated with length of hospital stay (β = -0.013, p = 0.026).

Elevated baseline Hb levels are correlated with preserved cognitive level and shorter hospital stays in post-stroke patients. Evaluating anemia at the outset serves as a crucial prognostic indicator.