Research Article

Measurement of the Red Blood Cell Distribution Width Improves the Risk Prediction in Cardiac Resynchronization Therapy

Table 4

Multivariable Cox regression analysis of the 5-year mortality with validation, calibration, and reclassification.

Basic model with RDW
+ NT-proBNP
Basic model
+ RDW
Basic modelBasic model
+ NT-proBNP
Basic model with NT-proBNP
+ RDW

Cox regression
 HR of RDW2.49 (1.27–4.86)2.81 (1.45–5.44)2.49 (1.27–4.86)
(RDW)0.0080.0020.008
 HR of NT-proBNP1.18 (0.93–3.51)2.19 (1.13–4.23)1.18 (0.93–3.51)
(NT-proBNP)0.070.010.07
Validation
 Overall 42.6240.4729.8635.3242.62
(overall)<0.0001<0.0001<0.0001<0.0001<0.0001
(changes)0.060.0010.010.004
Calibration
 HL test 8.266.720.484.018.26
(HL test) 0.400.560.990.850.40
Performance
 Brier score0.180.190.200.190.18
 Nagelkerke’s 0.300.280.210.260.30
Reclassification
-statistics0.76 (0.69–0.84)0.75 (0.66–0.83)0.71 (0.63–0.79)0.74 (0.66–0.82)0.76 (0.69–0.84)
(-statistics)0.800.030.040.39
 NRI (95% CI)0.14 (–0.03–0.33)0.64 (0.33–0.95)0.54 (0.23–0.84)0.64 (0.33–0.95)
(NRI)0.11<0.00010.0005<0.0001
 IDI (95% CI)0.01 (–0.00–0.03)0.05 (0.01–0.09)0.03 (0.00–0.06)0.03 (0.00–0.07)
(IDI)0.200.0030.040.01

The basic multivariable Cox regression model included left bundle branch block, beta-blocker therapy, and creatinine > 88.5 μmol/L. The RDW > 13.35% and NT-proBNP > 1975 pg/mL were adjusted separately to the basic model in a forward stepwise manner. The final common model included all variables. HR = hazard ratio; = chi squared; HL test = Hosmer-Lemeshow test; 95% CI = 95% confidence interval; -statistics = overall areas under the curve, assessed by the DeLong test; NRI = net reclassification improvement; IDI = integrated discrimination improvement. NT-proBNP = N-terminal pro-B-type natriuretic peptide; RDW = red blood cell distribution width.