Prognostic value of red blood cell distribution width for severe acute pancreatitis

Table 1 Characteristics of enrolled patients

Characteristic	Number
Total number of enrolled patients	42
Age (mean ± SD, yr)	47.15 ± 15.91
Gender, n (%)
Male	27 (64.29)
Female	15 (35.71)
BMI	26.67 ± 4.30
Etiology of SAP
Biliary tract disease	20
Alcoholism	8
Hypertriglyceridemia	7
Drug-induced	0
Others	7
Number of failed organs
1	12
2	9
≥ 3	7
Mortality at 90 d, n (%)	18 (42.86)

BMI: Body mass index; SAP: Severe acute pancreatitis.

Table 2 Demographic parameters between the survival and non-survival groups

Demographic parameter	Survival group	Non-survival group	P-value
Number	22	20
Age (yr)	50.50 ± 17.78	44.33 ± 13.28	0.206
Gender	Male (12): female (10)	Male (15): female (5)	0.720
BMI (kg/m2)	26.72 ± 4.61	26.59 ± 3.96	0.924
LOS-ICU (d)	7.71 ± 6.64	11.22 ± 14.40	0.347
RDW-CV (%)	13.59 ± 0.88	15.09 ± 1.63	0.002
RDW-SD (fL)	43.96 ± 3.11	49.94 ± 5.51	0.000
PDW (fL)	14.72 ± 3.35	14.95 ± 3.76	0.842
CRP (mg/L)	212.10 ± 107.04	212.19 ± 144.97	0.998
NLR	14.05 ± 10.13	9.92 ± 4.53	0.085
Serum calcium	1.64 ± 0.27	1.77 ± 0.45	0.253
APACHE II	12.42 ± 4.27	15.67 ± 5.70	0.041
SOFA	4.83 ± 2.65	7.94 ± 2.99	0.001

RDW-CV: Coefficient of variation of red blood cell distribution width; RDW-SD: Standard deviation of red blood cell distribution width; APACHE II: Acute Physiology and Chronic Health Evaluation II score; SOFA: Sequential Organ Failure Assessment score; BMI: Body mass index; LOS-ICU: Length of stay in the intensive care unit; NLR: Neutrophil to lymphocyte ratio; CRP: C reactive protein; PDW: Platelet distribution width.

Table 3 Correlation of red blood cell distribution width with Acute Physiology and Chronic Health Evaluation II score and Sequential Organ Failure Assessment score

Variable	RDW-CV		RDW-SD
	r	P-value	r	P-value
APACHE II	0.504	0.001	0.434	0.004
SOFA	0.414	0.006	0.380	0.012
Mortality	0.504	0.001	0.490	0.001

RDW-CV: Coefficient of variation of red blood cell distribution width; RDW-SD: Standard deviation of red blood cell distribution width; APACHE II: Acute Physiology and Chronic Health Evaluation II score; SOFA: Sequential Organ Failure Assessment score.

Table 4 Parameters of receiver operating characteristic curves

Parameter	AUC	SD	P-value	95% confidence interval
				Lower limit	Upper limit
RDW-CV	0.797	0.069	0.001b	0.662	0.933
RDW-SD	0.811	0.071	0.001d	0.673	0.950
APACHE II	0.677	0.089	0.052	0.504	0.851
SOFA	0.785	0.071	0.002f	0.646	0.924

RDW-CV: Coefficient of variation of red blood cell distribution width; RDW-SD: Standard deviation of red blood cell distribution width; APACHE II: Acute Physiology and Chronic Health Evaluation II score; SOFA: Sequential Organ Failure Assessment score; AUC: Area under the curve.

^bP < 0.05,

^dP < 0.01,

^fP < 0.05.

Table 5 Cut-off values for red blood cell distribution width

	Parameter	Sensitivity	Specificity	Youden index
RDW-CV	13.45	0.889	0.625	0.514
	13.55	0.833	0.667	0.500
	13.35	0.889	0.583	0.472
	13.65	0.778	0.667	0.445
RDW-SD	50.5	0.556	1	0.556
	51.5	0.5	1	0.500
	45.5	0.778	0.708	0.486
	49.5	0.556	0.917	0.473

RDW-CV: Coefficient of variation of red blood cell distribution width; RDW-SD: Standard deviation of red blood cell distribution width.

Table 6 Independent predictors of severe acute pancreatitis in a multivariate logistic regression analysis

Variable	Multivariate OR (95%CI)	P-value
RDW-CV	3.283 (1.503-7.174)	0.003
RDW-SD	1.368 (1.120-1.670)	0.002
APACHE II	1.172 (1.017-1.351)	0.028
SOFA	1.682 (1.212-2.332)	0.002

RDW-CV: Coefficient of variation of red blood cell distribution width; RDW-SD: Standard deviation of red blood cell distribution width; APACHE II: Acute Physiology and Chronic Health Evaluation II score; SOFA: Sequential Organ Failure Assessment score; AUC: Area under the curve; OR: Odds ratio CI: Confidence interval.

Table 7 Univariate Cox proportional hazards regression analysis (P = 0.001 for trend)

Variable	Multivariate OR (95%CI)	P-value
RDW-CV	1.615 (1.258-2.072)	0.000
RDW-SD	1.166 (1.077-1.261)	0.000
RDW-CV and RDW-SD	1.005 (1.003-1.008)	0.000
APACHE II	1.151 (1.048-1.264)	0.003
SOFA	1.363 (1.175-1.582)	0.000

RDW-CV: Coefficient of variation of red blood cell distribution width; RDW-SD: Standard deviation of red blood cell distribution width; APACHE II: Acute Physiology and Chronic Health Evaluation II score; SOFA: Sequential Organ Failure Assessment score; AUC: Area under the curve; OR: Odds ratio CI: Confidence interval.