Skip to main content

Table 2 Multivariable logistic regression analyses o postoperative AKI according to hyperchloremia exposure during PODs 0–3

From: Hyperchloremia and postoperative acute kidney injury: a retrospective analysis of data from the surgical intensive care unit

Group Variable Multivariable model 1
Overall AKI: OR (95% CI) P value
Entire sample
(n = 7991)
Hyperchloremiaa on POD 0 1.22 (0.94, 1.58) 0.144
Hyperchloremiaa on PODs 0–3 1.09 (0.80, 1.49) 0.571
Interaction of hyperCl on POD 0–3 with eGFR
  ≥ 90 mL·min−1·1.73·m− 2 1 (0.425)
 60–89 mL·min−1·1.73·m− 2 0.91 (0.62, 1.34) 0.629
 30–60 mL·min−1·1.73·m− 2 0.96 (0.65, 1.43) 0.840
  < 30 mL·min−1·1.73·m−2 0.70 (0.45, 1.08) 0.109
  Multivariable model 2
≥ Stage 2 AKI: OR (95% CI) P value
Hyperchloremiaa on POD 0 1.61 (0.89, 2.93) 0.367
Hyperchloremiaa on PODs 0–3 0.77 (0.40, 1.49) 0.437
Interaction of hyperchloremia with eGFR
  ≥ 90 mL·min−1·1.73·m−2 1 (0.468)
 60–89 mL·min− 1·1.73·m− 2 1.40 (0.67, 2.94) 0.367
 30–60 mL·min− 1·1.73·m− 2 0.64 (0.24, 1.69) 0.363
  < 30 mL·min− 1·1.73·m− 2 0.91 (0.17, 4.94) 0.915
  1. Covariates with P < 0.2 on univariable analysis (see also Additional file 3) were included in the final multivariable model to adjust for potential confounders. Covariates for multivariable model 1 included preoperative American Society of Anesthesiologists (ASA) score, preoperative estimated glomerular filtration rate (eGFR), NaCl 0.9% and balanced crystalloid infused. Covariates for multivariable model 2 included preoperative ASA score, preoperative eGFR, cardiovascular surgery, NaCl 0.45% and hydroxyethyl starch infused. The Hosmer-Lemeshow goodness-of-fit test was performed to investigate the fitness of the multivariable logistic regression model, and revealed no indication of lack of fit (Model 1: Hosmer-Lemeshow statistic 7.09, P = 0.527; Model 2: Hosmer-Lemeshow statistic 6.287, P = 0.615)
  2. AKI acute kidney injury, CI confidence interval, POD postoperative day
  3. aHyperchloremia was defined as serum chloride levels ≥ 110 mmol·L− 1
  4. bPreoperative eGFR (mL·min− 1·1.73·m− 2) was calculated using the Modification of Diet in Renal Disease formula: 186 × (preoperative serum Creatinine)-1.154 × (Age)-0.203 (× 0.742 if female)