Supplementary Material for: Predictors of Supratentorial Deep Intracerebral Hemorrhage Volume and Their Effect on Short-Term Mortality in Asians

Background: The volume of intracerebral hemorrhage (ICH) measured at hospital admission is the strongest predictor of clinical outcomes in patients with ICH. Despite the high incidence rate of ICH in Asians, there is lack of data regarding predictors of ICH volume in this ethnic group. The purpose of this study was to determine predictors of deep ICH volume and examine their effect on short-term mortality in Asians. Methods: Hematoma volume was measured using the ABC/2 method. ICH volume was transformed to the natural log scale to normalize distributions for all analyses. We estimated the coefficients of ICH volume based on relevant predictors using multivariable linear regression. We also determined the association between body mass index (BMI) and ICH volume using a regression line and a line determined by a locally weighted scatter plot smoothing. Results: A total of 1,039 patients from 2 twin hospitals in Korea who were admitted with primary spontaneous supratentorial deep ICH over a 12-year period were enrolled in this study. The median ICH volume was 19.7 ml. The average patient age was 59.2, and 62.4% of patients were men. The mean ICH volume showed a gradual, approximately 2% decrease per 1 BMI increase in the current study, after adjusting for all relevant variables (β = -0.024; SE 0.004; p < 0.001). In addition, patients with frequent alcohol consumption showed a 10% increase in mean ICH volume (β = 0.098; SE 0.041; p = 0.016), and patients undergoing warfarin treatment showed a 30% increase in mean ICH volume after full adjustment of all relevant variables (β = 0.296; SE 0.050; p < 0.001). Relative to overweight patients, there was a 47, 11, and 18% increase in admission mean ICH volume in underweight, normal weight and obese patients, respectively. Patients in the first quartile and underweight BMI groups had 1.45-fold (hazard ratio (HR) 1.45; 95% CI 1.03-2.03; p = 0.035) and 1.77-fold (HR 1.77; 95% CI 1.10-2.84; p = 0.019) higher increased risk of death during the first 3 months after ICH, retrospectively. In addition, patients in groups with frequent alcohol consumption and warfarin use both showed a significant association with mortality 90 days after ICH. Conclusions: We demonstrated the association between various predictors and admission ICH volume with short-term mortality in Asians. Further studies are needed to account for these observations and determine their underlying mechanisms.