Figure 4.

The pattern of association of postdialysis hypokalemia with mortality different by baseline predialysis potassium level, but this effect modification was not statistically significant (interaction P=0.09). The numbers of patients in the high, medium, and low predialysis K groups were 790, 1892, and 1280, respectively. Five patients were excluded from this analysis because their predialysis K level was missing. The reference (HR=1) was 3.5mEq/L. The definition of subgroups is as follows: low, <4.5 mEq/L; medium, 4.5 to <5.5 mEq/L; and high, ≥5.5 mEq/L.