Nomogram-based prediction of post-splenectomy thrombocytosis in children with hereditary spherocytosis

Table 1 Clinical characteristics of children with hereditary spherocytosis undergoing splenectomy, mean ± SD

Variables	Thrombocytosis group (n = 158)	Normal platelet group (n = 72)	P value
Age (years)	9.4 ± 2.3	9.1 ± 2.5	0.36
Sex (male/female)	90/68	42/30	0.88
Body mass index (kg/m2)	18.9 ± 2.4	18.6 ± 2.2	0.42
Preoperative Hb (g/L)	92.1 ± 11.6	94.5 ± 12.2	0.27
Reticulocyte (%)	5.6 ± 1.8	4.9 ± 1.6	0.03
History of transfusion, n (%)	45 (28.5)	17 (23.6)	0.41
Splenic size (longest diameter, cm)	15.2 ± 2.1	14.9 ± 2.3	0.49

P values were calculated using independent t-test or χ² test as appropriate. Hb: Hemoglobin.

Table 2 Comparison of postoperative platelet parameters between groups, mean ± SD

Variables	Thrombocytosis group (n = 158)	Normal platelet group (n = 72)	P value
Platelet count (× 109/L)	689.2 ± 103.5	342.8 ± 84.6	< 0.001
Mean platelet volume (fL)	9.1 ± 1.2	10.2 ± 1.3	< 0.001
Plateletcrit (%)	0.35 ± 0.07	0.21 ± 0.05	< 0.001
Platelet distribution width (%)	14.8 ± 2.1	13.9 ± 1.9	0.04

P values were obtained using independent t-test.

Table 3 Multivariate logistic regression analysis of risk factors for postoperative thrombocytosis

Variables	OR	95%CI	P value
Reticulocyte (%)	1.42	1.11-1.83	0.004
Preoperative platelet count	1.27	1.08-1.56	0.02
Mean platelet volume	0.81	0.69-0.95	0.01
Transfusion volume	1.35	1.05-1.72	0.03
Splenic size (cm)	1.10	0.92-1.32	0.18

P < 0.05 was considered statistically significant. Odds ratios and 95% confidence intervals were estimated using multivariate logistic regression. OR: Odds ratios; CI: Confidence intervals.

Table 4 Discriminatory ability of predictors (receiver operating characteristic analysis)

Predictors	AUC	95%CI	P value
Reticulocyte (%)	0.79	0.73-0.85	< 0.001
Preoperative platelet count	0.76	0.69-0.83	0.002
Transfusion volume	0.78	0.72-0.84	0.001
MPV	0.73	0.66-0.80	0.004
Combined model	0.92	0.87-0.96	< 0.001

Receiver operating characteristic curve analysis was performed to evaluate the predictive ability of individual parameters and the combined model. AUC: Area under the curve; CI: Confidence interval; MPV: Mean platelet volume.