Our eight final summary stressors were created by standardizing each stressor (into a z-score) and then summing all indicators of stressors composing a given domain, restandardizing the resulting summary measure to facilitate comparisons across domains, and dichotomously scoring the final variable, to contrast scores in the top quintile (“high stress”) versus all others. Focusing on the top quintile allows us to capture both severity and accumulation of stressors. We chose a top-quintile threshold based on prior research that indicates that the negative effects of stressors are most clearly evident among those experiencing chronic, cumulative, and severe stressors (Williams and Mohammed, 2009). Sensitivity analyses utilizing alternative thresholds (top tertile, top quartile) revealed similar results.
