Statistical methods

All statistical analyses were performed using R 4.1.1 (https://www.R-project.org/). We compared participant demographic and psychological measures in the Black versus non-Hispanic, White group using Welch t-tests and non-parametric Wilcoxon Rank-Sum tests for continuous measures and Fisher's exact tests for categorical measures. P-values were adjusted for multiple comparisons using the FDR method. In order to examine the factors contributing to PTG, a hierarchical multiple linear regression model was computed with PTG as the outcome variable and with age, sex, socioeconomic status, race, perceived stress, and coping mechanisms as the predictors. The level 1 model included only the demographic effects of age, sex, race, and SES, while the level 2 model added the psychological factors of perceived stress and coping mechanisms. In both linear models, continuous variables were standardized (z-score transformation) before inclusion, and the conditions of linearity, homoscedasticity of errors, normal distribution of residuals, lack of outliers, and lack of multicollinearity were all confirmed to be met. In addition, a confirmatory matched analysis between the Black and non-Hispanic, White group was performed using a sample matched on age, gender, and SES in predicting PTG.