Table 3.

Trainee performance assessed by multilevel multivariable regression. NASA-TLX comparisons are omitted from this table as there were no significant differences between experience levels – see Discussion.

	Intermediate vs. Novice	Advanced vs. Novice	Expert vs. Novice
	Estimated difference from regression analysis (95% CI) p-value
Operation Specific Metrics
Clamp Times (minutes)	−1.9	−8.8	−12.4
	(−7.0, 3.2)	(−13.9, −3.7)	(17.6, −7.3)
	0.50	0.005	<0.001
Positive Margins**	1.02	0.54	0.50
	(0.12, 8.5)	(0.05, 4.5)	(0.04, 4.0)
	0.99	0.54	0.50
Proportion Renal Parenchyma Preserved	0.001	−0.010	−0.010
	(−0.012, 0.014)	(−0.023, 0.004)	(−0.024, 0.003)
	0.91	0.19	0.16
GEARS Score
Depth Perception	−0.17	1.3	1.3
	(−0.94, 0.61)	(0.56, 2.1)	(0.56, 2.1)
	0.69	0.004	0.004
Bimanual Dexterity	−0.083	1.1	1.5
	(−0.74, 0.57)	(0.43, 1.7)	(0.84, 2.2)
	0.82	0.006	<0.001
Efficiency	−0.50	0.92	1.3
	(−1.20, 0.20)	(0.21, 1.6)	(0.55, 2.0)
	0.20	0.025	0.004
Force Sensitivity	−0.083	1.6	1.9
	(−0.66, 0.49)	(1.0, 2.2)	(1.3, 2.5)
	0.82	<0.001	<0.001
Autonomy	−0.083	1.2	1.7
	(−0.28, 0.12)	(0.97, 1.4)	(1.5, 1.9)
	0.75	<0.001	<0.001
Robotic Control	−0.25	0.92	1.2
	(−0.54, 0.056)	(0.62, 1.2)	(0.87, 1.5)
	0.46	0.012	0.002

^*Multilevel multivariable linear and logistic regression models were used to test the association of performance metrics against the independent variables, trial number and experience level.

^**Positive margins represent the only binary variable, and the “Estimate” column is the odds ratio from logistic regression in this case.