Table 5.
Association of mortality with 1-L increase in 4-month running mean of Vm in different subgroups or situations
| Factor | Subgroup or Situation | HR | 95% CI | P in Subgroup or Condition | Interaction P |
|---|---|---|---|---|---|
| Direction of change in Vm | Decrease in Vm | 1.00 | (0.97 to 1.04) | 0.90 | — |
| Increase in Vm | 1.08 | (1.06 to 1.11) | <0.001 | ||
| Weight change | >2 kg | 1.13 | (1.06 to 1.21) | <0.001 | 0.04 |
| −2 to 2 kg | 1.10 | (1.06 to 1.14) | <0.001 | ||
| < −2 kg | 1.05 | (1.02 to 1.08) | 0.004 | ||
| Gender | Male | 1.05 | (1.02 to 1.08) | 0.004 | 0.008 |
| Female | 1.11 | (1.08 to 1.15) | <0.001 | ||
| Baseline Vant | Vant < 35 L | 1.08 | (1.05 to 1.11) | <0.001 | 0.95 |
| Vant > 35 L | 1.08 | (1.04 to 1.12) | <0.001 | ||
| Diabetic status | Nondiabetic | 1.09 | (1.05 to 1.12) | <0.001 | 0.63 |
| Diabetic | 1.07 | (1.04 to 1.11) | <0.001 | ||
| Dose group | Standard dose | 1.10 | (1.06 to 1.13) | <0.001 | 0.24 |
| High dose | 1.07 | (1.04 to 1.10) | <0.001 | ||
| Vascular access issue | No access issues | 1.07 | (1.04 to 1.11) | <0.001 | 0.92 |
| ≥1 access issue | 1.07 | (1.04 to 1.11) | <0.001 | ||
| Vascular access issue or time or shortened time | No access or time issues | 1.06 | (1.03 to 1.10) | <0.001 | 0.40 |
| ≥1 access or time issue | 1.08 | (1.05 to 1.11) | <0.001 |
All HRs are based on time-dependent Cox regressions relating mortality to changes in the 4-month mean Vm levels over the preceding 6 months, adjusting for the case mix variables, baseline anthropometric volume, the assigned dose, and flux groups, and the 4-month running mean volume lagged by 6 months. The analyses were stratified by clinical center. Increases and decreases in the running mean Vm were modeled separately using a linear spline model; only HRs for increases in Vm are shown for the asterisked rows. The HRs evaluate the change in risk associated with a 1-L increase in Vm, which represents 25% of 1 SD (4.01 L) of the changes in the 4-month running mean Vm.