Table 2.

Baseline characteristics of GIST patients stratified by Ki-67 proliferation index in different datasets

	Training			Validation 1			Validation 2
	Low Ki-67 PI (n = 191)	High Ki-67 PI (n = 27)	p	Low Ki-67 PI (n = 87)	High Ki-67 PI (n = 9)	p	Low Ki-67 PI (n = 57)	High Ki-67 PI (n = 12)	p
Age (years)	61.42 ± 11.70	57.33 ± 13.25	0.096	62.59 ± 13.24	60.33 ± 5.24	0.615	62.30 ± 13.14	56.75 ± 12.17	0.183
Gender			0.310			0.181			1.000
Female	99 (51.83%)	11 (40.74%)		41 (47.13%)	2 (22.22%)		30 (52.63%)	6 (50.00%)
Male	92 (48.17%)	16 (59.26%)		46 (52.87%)	7 (77.78%)		27 (47.37%)	6 (50.00%)
Diameter (mm)	51.68 ± 39.77	78.55 ± 39.60	0.001	51.28 ± 39.51	90.52 ± 41.03	0.006	55.79 ± 38.18	90.36 ± 51.32	0.009
CER (%)	2.30 ± 0.82	1.96 ± 0.70	0.042	2.33 ± 0.78	1.75 ± 0.36	0.030	2.32 ± 0.79	1.88 ± 0.50	0.070

CER, contrast enhancement ratio; PI, proliferation index