Table IV.

Estimated influence of number of core staff on total knee arthroplasty operative efficiency. Models were adjusted for body mass index, American Society of Anesthesiologists grade, and presence of arthritic changes.

	Incision time		Procedure time		Room time
Variable	Estimated change in duration, mins	p-value*	Estimated change in duration, mins	p-value*	Estimated change in duration, mins	p-value*
Number of residents	−5.0	0.370	−5.4	0.392	−5.5	0.401
Number of circulating nurses	9.7	0.148	9.0	0.233	2.5	0.740
Number of scrub nurses	−0.7	0.882	4.2	0.429	5.9	0.282
Number of vendor representatives	7.4	0.277	6.0	0.435	2.6	0.741
Number of anaesthesiologists	20.0	0.011	19.5	0.025	10.8	0.212

^*Multivariate linear regression.