Table 4.

Multivariable linear regression coefficients for the association of ACT^a and SCT^b with ASA^c, hospital, and surgeon.

Outcome and variable			Total hip arthroplastyd							Total knee arthroplastye
			Estimates (min)		95% CI		P value		Estimates (min)			95% CI		P value
ACT
	Coefficient intercept	22.13		20.02 to 24.24		<.001		20.53			18.87 to 22.18		<.001
	ASA class III/IV	3.76		2.00 to 5.51		<.001		1.33			–0.18 to 2.84		.08
	AMCf	3.50		1.58 to 5.42		<.001		3.50			1.82 to 5.18		<.001
	Surgeon 1	–2.03		–3.81 to –0.25		.03		–1.53			–3.02 to –0.03		.045
SCT
	Coefficient intercept	102.18		96.56 to 107.80		<.001		101.56			96.02 to 107.11		<.001
	ASA class III/IV	6.33		1.66 to 10.99		.008		2.61			–2.46 to 7.67		.31
	AMC	10.69		5.58 to 15.79		<.001		13.82			8.19 to 19.44		<.001
	Surgeon 1	–2.87		–7.60 to 1.86		.23		–10.36			–15.36 to –5.36		<.001

^aACT: anesthesia-controlled time.

^bSCT: surgery-controlled time.

^cASA: American Society of Anesthesiologists.

^dACT for total hip arthroplasty had 609 observations and an R²/R² adjusted value of 0.061/0.056; and total knee arthroplasty had 624 observations and an R²/R² adjusted value of 0.037/0.003.

^eSCT for total hip arthroplasty had 609 observations and an R²/R² adjusted value of 0.043/0.039; and total knee arthroplasty had 624 observations and an R²/R² adjusted value of 0.060/0.055.

^fAMC: academic medical center.