The four levels of psychological distress were combined in pairs ('low'/'moderate', and 'high'/'very high') to form a binary variable for subsequent statistical modelling. Figure 1 shows the prevalence of this binary high/low psychological distress variable by EI disease zones. Respondents in the red and amber zones reported higher prevalence of high psychological distress (41% and 39%, respectively) than those in the purple, green, and white zones (36%, 34%, and 26% respectively).