Prediction of successful weaning from renal replacement therapy in critically ill patients based on machine learning

Figures & data

Figure 1. The research flow chart and schematic diagram of sampling time range and outcome of RRT withdrawal with variables.

Table 1. Baseline characteristic and variables of weaning from RRT in severe acute kidney injury patients in ICU.

Variables	Successful weaning from RRT; N = 349	Failure of RRT weaning; N = 627	p	OR [95%CI]
Gender, male	226 (64.8%)	417 (66.5%)	0.580	0.972 [0.88–1.08]
Age (years)	62.0 ± 17.6	61.2 ± 17.3	0.514
BMI (kg/m^2)	22.6 ± 3.8	22.5 ± 3.9	0.43
Primary disease
Infections	111 (31.8%)	192 (30.6%)	0.70	1.06 [0.79–1.40]
Trauma	44 (12.6%)	85 (13.6%)	0.67	0.92 [0.62–1.36]
Cardio-cerebrovascular accident	8 (2.3%)	50 (8.0%)	<0.001	0.27 [.012–0.58]
Heart disease	62 (17.8%)	147 (23.4%)	0.038	0.71 [0.51–0.98]
Internal medicine diseases	50 (14.3%)	79 (12.6%)	0.45	1.16 [0.79–1.70]
Postoperative diseases	74 (21.2%)	74 (11.8%)	<0.001	2.01 [1.41–2.86]
Diabetes mellitus	62 (17.7%)	109 (17.4%)	0.881	1.02 [0.73–1.45]
Malignant tumor	56 (16.0%)	69 (11.0%)	0.024	1.54 [1.06–2.26]
Hypertension	140 (40.1%)	269 (42.9%)	0.397	0.89 [0.68–1.16]
Scrmax (μmol/L, IQR)	169.0 [114.0–296.0]	226.0 [212.0–321.0]	<0.001
Scrmin (μmol/L, IQR)	84.0 [53.0–131.0]	82.0 [54.0–128.0]	0.926
BUNmax (mmol/L, IQR)	14.8 [9.3–24.1]	21.8 [14.2–33.0]	<0.001
WBCmax (10^9/L, IQR)	14.2 [9.4–22.2]	15.6 [10.3–22.8]	0.30
Hbmin (g/L, IQR)	65.0 [56.0–78.0]	63.0 [52.0–75.0]	0.003
PLTmin (10^9/L, IQR)	42.0 [14.0–111.0]	48.0 [18.0–97.0]	0.996
LYMmax (10^9/L, IQR)	0.9[0.4–1.0]	0.9 [0.3–1.0]	0.115
CRPmax (mg/L, IQR)	73.8 [32.5–143.0]	109.4 [48.6–182.4]	<0.001
ALTmax (U/L, IQR)	50.0 [24.0–138.0]	50.0 [24.0–202.0]	0.659
ASTmax (U/L, IQR)	67.0 [37.0–264.0]	91.0 [40.0–356.0]	0.549
Serum cystatin Cmax (mg/L, IQR)	1.2 [1.0–2.2]	3.2 [1.7–4.3]	<0.001
Tbilmax (μmol/L, IQR)	23.0 [16.0–64.0]	27.1 [16.8–49.4]	0.035
Total proteinmax (μmol/L, IQR)	48 [42.6–55.4]	50.0 [43.9–56.4]	0.003
Albuminmax (g/L, IQR)	25.0 [21.7–28.4]	25.8 [22.0–29.4]	0.007
PTmax (s, IQR)	20.6 [15.8–26.1]	21.6 [16.9–28.8]	<0.001
APTTmax (s, IQR)	76.1 [59.1–106.1]	76.0 [57.6–105.3]	0.795
FIGmax (g/L, IQR)	2.1 [1.3-3.7]	2.8 [1.6-4.2]	<0.001
D-dimermax (ug/L, IQR)	10390.0 [4500.0–20000.0]	10720.0 [5390.0–20000.0]	0.755
Urine volume in 72 h before weaning from RRT (mL/d, IQR)	755.0 [105.0–2350.0]	125 [20.0–300.0]	<0.001
CRRT duration (d, IQR)	7.0 [2.0–15.0]	9.6 [2.5–16.8]	<0.001
Positive FST	210 (60.2%)	255 (40.7%)	<0.001	2.20 [1.69–2.88]
History of glucocorticoid	129 (36.9%)	213 (34.0%)	0.348	1.14 [0.86–1.50]
History of aspirin	42 (12.0%)	113 (18.0%)	0.014	0.62 [0.42–0.91]
Septic shock	98 (28.1%)	260 (41.5%)	<0.001	0.55 [0.42–0.73]
High VIS	157 (45.0%)	350 (55.8%)	0.001	0.65 [0.49–0.84]
Invasive catheterization	203 (58.2%)	366 (58.4%)	0.95	0.99 [0.76–1.29]
History of ECMO	25 (7.2%)	51 (8.1%)	0.588	0.87 [0.53–1.43]
Invasive procedure	128 (36.7%)	349 (55.7%)	<0.001	0.46 [0.35–0.60]
Operation history	157 (45.0%)	272 (43.4%)	0.628	1.07 [0.82–1.39]
Ward admission	86 (24.6%)	111 (17.7%)	0.01	1.52 [1.11–2.09]
Emergency admission	269 (77.1%)	523 (83.4%)	0.015	0.67 [0.48–0.93]
Survival rate in 30 d	141 (40.4%)	192(30.6%)	0.002	1.53 [1.17–2.02]
Hospitalization frequency (d, IQR)	2.0 [1.0–4.0]	2.2 [1.0–5.0]	0.088
LOS (d, IQR)	13.9 [5.7–28.0]	17.0 [4.5–32.0]	0.519

RRT: renal replacement therapy; CRRT: continuous renal replacement therapy; BMI: body mass index; Scr: serum creatinine; BUN: blood urea nitrogen; WBC: white blood cell count; Hb: hemoglobin; PLT: platelet; LYM: lymphocyte count; CRP: C-reactive protein; ALT: glutamic-pyruvic transaminase; AST: glutamic oxalacetic transaminase; Tbil: total bilirubin; PT: prothrombin time; APTT: activated partial thromboplastin time; FIG: fibrinogen; FST: furosemide stress test; VIS: vasoactive-inotropic score; ECMO: Extracorporeal Membrane Oxygenation; LOS: length of stay

Table 2. Parameters in the multivariable logistic regression model of weaning from RRT in severe AKI patients.

Value	p	OR [95%CI]
CRRT duration	0.002	0.94 [0.92–0.96]
CRPmax	0.003	0.91 [0.90–0.92]
Homocysteinemax	<0.001	0.46 [0.40–0.53]
Urine volume in 72 h before weaning from RRT	<0.001	2.12 [1.03–3.34]
Ptmax	<0.001	0.97 [0.96–0.98]
Positive FST	<0.001	2.75 [1.98–3.83]
Septic shock	<0.001	0.63 [0.45–0.89]
Invasive procedure	<0.001	0.33 [0.23–0.46]

RRT: renal replacement therapy; CRRT: continuous renal replacement therapy; PT: prothrombin time; CRP: C-reactive protein; FST: furosemide stress test; OR: odds ratio; CI: confidence interval

Figure 2. The AUROC curve of validation set and test set in prediction model of weaning from RRT.

Figure 3. Visual histogram of variable importance of XGBoost.

Table 3. Model validation results with machine learning algorithms.

Validation	AUROC	Accuracy	Sensibility	Specificity	PPV	NPV	F1
MLR	0.83	0.814	0.615	0.887	0.667	0.863	0.640
DT	0.87	0.835	0.731	0.873	0.679	0.899	0.704
SVM	0.88	0.825	0.654	0.887	0.680	0.875	0.667
RF	0.93	0.907	0.808	0.944	0.840	0.931	0.824
XGBoost	0.93	0.887	0.769	0.930	0.800	0.917	0.784
Test
MLR	0.75	0.818	0.567	0.928	0.773	0.831	0.654
DT	0.83	0.859	0.767	0.899	0.767	0.899	0.767
SVM	0.84	0.808	0.633	0.884	0.704	0.847	0.667
RF	0.95	0.889	0.800	0.928	0.828	0.914	0.814
XGBoost	0.93	0.869	0.800	0.899	0.774	0.912	0.787

Availability of data and materials

The datasets used and/or analyzed during this study are available from the corresponding author on reasonable request.