Table 2.

Patient proportion of surgical difficulty for tLAR according to BLADE scoring system.

	Derivation set	Training set	Test set	External validation set
Operation time score, n (%)
0	863 (43.3)	690 (43.2)	173 (43.5)	288 (69.6)
1	1,131 (56.7)	906 (56.8)	225 (56.5)	126 (30.4)
Operative blood loss score, n (%)
0	1,158 (58.1)	928 (58.1)	230 (57.8)	233 (56.3)
1	836 (41.9)	668 (41.9)	168 (42.2)	181 (43.7)
BLADE score, n (%)
0	517 (25.9)	406 (25.4)	111 (27.9)	166 (40.1)
1	989 (49.6)	807 (50.6)	182 (45.7)	189 (45.7)
2	488 (24.5)	383 (24.0)	105 (26.4)	59 (14.3)

tLAR, total laparoscopic anterior resection; BLADE, blood loss and duration of excision.