Background:
The Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) is an ongoing case-control study of spontaneous ICH among non-hispanic whites, non-hispanic blacks, and Hispanics. Prior studies have identified hypertension as a greater risk for non-lobar (NL) ICH as compared with lobar (L) ICH. Given the greater reported prevalence of hypertension among black and Hispanic populations, we hypothesized that the location of ICH may differ by race/ethnicity.
Methods:
At the time of this analysis, we had ICH location data, lobar vs. non-lobar, on 648 subjects. We performed univariate analysis on known and potential predictors of ICH location: age, sex, race/ethnicity, hypertension, diabetes, BMI, creatinine, cholesterol, aspirin use, smoking, alcohol use, caffeine use, and INR. INR was dichotomized at >1.1. After forcing in age, sex, race, history of diabetes, aspirin use and INR, we added significant and near-significant (p<0.2) variables in a stepwise fashion to complete our final logistic regression model. Our outcome measure was lobar ICH. Conditional pairwise testing was performed for race/ethnicity.
Results:
Of the 648 subjects (mean age 61.12 ± 14.51 years; 39.8% female; 35.0% Hispanic, 26.5% white, 38.4% black), 181 (27.9%) presented with lobar ICH. Hypertension was present in 525 subjects (75.1% L, 83.3% NL; p=.018), diabetes in 152 (26.0% L, 22.5% NL; p=.348), high cholesterol in 244 (45.9% L, 34.5% NL; p=.008), aspirin use in 200 (37.0% L, 28.5% NL; p=.035), and INR >1.1 (24.1% L, 21.8% NL; p=.535) In our final model, race/ethnicity (p<.024) was associated with location of ICH. Furthermore, white race/ethnicity was associated with L ICH, compared with black (b=.57, p=.016) or Hispanic (b=.56, p=.018). Hypertension (b=-0.63, p=.009) was associated with NL ICH, and smoking (b=0.51, p=.007) was associated with L ICH.
Discussion:
Our results suggest that there are significant racial/ethnic differences in the distribution of lobar and non-lobar ICH. The conditional pairwise testing for race/ethnicity showed a significantly higher rate of lobar ICH in whites, compared with blacks or Hispanics. These findings are intriguing given the differences in case-fatality rates and age at ICH onset.
Combining genetic algorithm and pairwise testing for optimised test generation from UML ADs
