BP changes during the DASH-Sodium trial. Although arrows are unidirectional, the order in which individuals were assigned a given salt level was random with a crossover design. The numbers next to the lines connecting the data points are the mean changes in BP. The 95% confidence intervals are given in parentheses. *P < 0.05, ^†P < 0.01, and ^#P < 0.001; symbols indicate significant differences in BP between groups or between dietary sodium categories. Reproduced with permission from the New England Journal of Medicine (54).