Table 3.
Unadjusted and case-mix adjusted associations between mannitol administration and hemodynamic parameters
| Difference for mannitol (vs no mannitol)a |
||
|---|---|---|
| Unadjusted | Adjusted b | |
|
|
||
| Pre-dialysis SBP (mmHg) | 0.6 (−9.0, 10.2) p=0.9 |
1.9 (−7.3, 11.2) p=0.68 |
| Nadir SBP (mmHg) | 6.9 (−1.6, 15.4) p=0.11 |
5.4 (0.6, 10.2) p=0.03 |
| Log drop in SBP (mmHg) | −0.36 (−0.65, −0.06) p=0.02 |
−0.29 (−0.54, −0.03) p=0.03 |
Generalized linear models were fit using clustered variances to account for non-independence of individuals. Effect estimates presented are beta coefficients, 95% confidence intervals and p values testing for the effect of mannitol administration versus standard therapy.
Adjusted effect estimates were estimated by adding age, sex, diabetes, access (catheter vs non-catheter), pre-dialysis SBP and congestive heart failure to the model. Pre-dialysis SBP was omitted from the covariate list in the model considering it as the dependent variable.
Exponentiation of the beta coefficient provides and estimate of the ratio of the geometric mean in SBP decline in patients treated with mannitol vs those who did not receive mannitol. Unadjusted analysis reveals a ratio of 0.70 (30% less decline in SBP; 13.7 vs 19.6mmHg); adjusted analysis reveals a ratio of 0.75 (25% less decline in SBP; 16.3 vs 21.8mmHg when considering a male, diabetic, aged 62 years, using a catheter, with heart failure and pre-dialysis SBP of 142mmHg).
SBP, systolic blood pressure