. 2019 Jul 16;34(4):1745–1753. doi: 10.1007/s00464-019-06961-1

Table 2.

Hierarchical task analysis used in the trial.

Adapted from the reports by Joice et al. [14] and Tang et al. [11]

Task	Start point	End point	Trial arm	Median (IQR) (s)	p	Dependent variable of natural log of time. Partial η²	p
1. Dissection of Calot’s triangle	Grasping of fundus and elevating	Clear identification of cystic artery and duct	2D	724 (380–1068)	0.061	0.063	0.013
1. Dissection of Calot’s triangle	Grasping of fundus and elevating	Clear identification of cystic artery and duct	3D	540 (288–792)	0.061	0.063	0.013
2. Clipping and dividing cystic artery and cystic duct	Appearance of clip applicator	Cystic artery and duct divided	2D	140.5 (44–237)	0.23	0.007	0.414
2. Clipping and dividing cystic artery and cystic duct	Appearance of clip applicator	Cystic artery and duct divided	3D	182 (76–288)	0.23	0.007	0.414
3. Detaching gallbladder from liver bed	At completion of cystic artery and duct division	Gallbladder fully removed from liver bed	2D	324.5 (203.5–445.5)	0.894	0.000	0.941
3. Detaching gallbladder from liver bed	At completion of cystic artery and duct division	Gallbladder fully removed from liver bed	3D	281 (196–366)	0.894	0.000	0.941
Total operative time	Grasping of fundus and elevating	Gallbladder fully removed from liver bed	2D	1287 (834–1783)	0.148	0.039	0.056
Total operative time	Grasping of fundus and elevating	Gallbladder fully removed from liver bed	3D	1070 (790–1616)	0.148	0.039	0.056

Time (s) is displayed. No differences are seen in the direct comparison but after natural transformation a significant difference in Calot’s dissection alone is seen