Stroke severity mediates the effect of socioeconomic disadvantage on poor outcomes among patients with intracerebral hemorrhage

Abstract

Background: Socioeconomic deprivation drives poor functional outcomes after intracerebral hemorrhage (ICH). Stroke severity and background cerebral small vessel disease (CSVD) burden have each been linked to socioeconomic status and independently contribute to worse outcomes after ICH, providing distinct, plausible pathways for the effects of deprivation. We investigate whether admission stroke severity or cerebral small vessel disease (CSVD) mediates the effect of socioeconomic deprivation on 90-day functional outcomes.

Methods: Electronic medical record data, including demographics, treatments, comorbidities, and physiological data, were analyzed. CSVD burden was graded from 0 to 4, with severe CSVD categorized as ≥3. High deprivation was assessed for patients in the top 30% of state-level area deprivation index scores. Severe disability or death was defined as a 90-day modified Rankin Scale score of 4-6. Stroke severity (NIH stroke scale (NIHSS)) was classified as: none (0), minor (1-4), moderate (5-15), moderate-severe (16-20), and severe (21+). Univariate and multivariate associations with severe disability or death were determined, with mediation evaluated through structural equation modelling.

Results: A total of 677 patients were included (46.8% female; 43.9% White, 27.0% Black, 20.7% Hispanic, 6.1% Asian, 2.4% Other). In univariable modelling, high deprivation (odds ratio: 1.54; 95% confidence interval: [1.06-2.23]; p = 0.024), severe CSVD (2.14 [1.42-3.21]; p < 0.001), moderate (8.03 [2.76-17.15]; p < 0.001), moderate-severe (32.79 [11.52-93.29]; p < 0.001), and severe stroke (104.19 [37.66-288.12]; p < 0.001) were associated with severe disability or death. In multivariable modelling, severe CSVD (3.42 [1.75-6.69]; p < 0.001) and moderate (5.84 [2.27-15.01], p < 0.001), moderate-severe (27.59 [7.34-103.69], p < 0.001), and severe stroke (36.41 [9.90-133.85]; p < 0.001) independently increased odds of severe disability or death; high deprivation did not. Stroke severity mediated 94.1% of deprivation's effect on severe disability or death (p = 0.005), while CSVD accounted for 4.9% (p = 0.524).

Conclusion: CSVD contributed to poor functional outcome independent of socioeconomic deprivation, while stroke severity mediated the effects of deprivation. Improving awareness and trust among disadvantaged communities may reduce admission stroke severity and improve outcomes.

Keywords: cerebral small vessel disease; intracerebral hemorrhagic stroke; mediation analysis; patient outcomes; socioeconomic disadvantage.