Productivity Improvements in Hip and Knee Surgery

Table 3

Average treatment effects on the treated (ATT) for 1998–2010 and subperiods.

Outcome levels	Hip				Knee
	Observations	ATT	95% Confidence interval		Observations	ATT	95% Confidence interval
All-year periods
ADL limitations	1,220	−0.10	(−0.23, 0.04)		4,004	−0.21	(−0.28, −0.14)	*
IADL limitations	1,220	−0.14	(−0.26, −0.03)	*	4,004	−0.14	(−0.20, −0.09)	*
Mobility limitations	1,220	−0.34	(−0.52, −0.16)	*	4,006	−0.46	(−0.56, −0.36)	*
Large muscle index	1,220	−0.24	(−0.38, −0.10)	*	4,004	−0.24	(−0.31, −0.16)	*
Fine motor index	1,220	0.02	(−0.06, 0.10)		4,004	−0.10	(−0.14, −0.06)	*
Gross motor index	1,220	−0.33	(−0.49, −0.17)	*	4,004	−0.33	(−0.41, −0.24)	*
Pain	1,222	−0.23	(−0.28, −0.18)	*	4,004	−0.19	(−0.21, −0.16)	*
Pain restrict	1,222	−0.24	(−0.29, −0.18)	*	4,004	−0.20	(−0.23, −0.17)	*
Subperiod results
ADL limitations
1998–2000	340	0.07	(−0.21, 0.35)		958	−0.14	(−0.29, 0.01)
2002–2006	496	−0.11	(−0.31, 0.09)		1,812	−0.15	(−0.26, −0.05)	*
2008–2010	382	−0.17	(−0.41, 0.07)		1,228	−0.21	(−0.33, −0.09)	*
IADL limitations
1998–2000	340	−0.01	(−0.24, 0.21)		958	−0.05	(−0.16, 0.07)
2002–2006	496	−0.12	(−0.28, 0.03)		1,812	−0.10	(−0.19, −0.02)	*
2008–2010	382	−0.25	(−0.47, −0.03)	*	1,228	−0.17	(−0.27, −0.07)	*
Mobility limitations
1998–2000	340	−0.69	(−1.04, −0.34)	*	958	−0.43	(−0.64, −0.22)	*
2002–2006	496	−0.43	(−0.71, −0.15)	*	1,812	−0.52	(−0.67, −0.37)	*
2008–2010	382	−0.50	(−0.83, −0.17)	*	1,228	−0.48	(−0.66, −0.31)	*
Large muscle index
1998–2000	340	−0.21	(−0.47, 0.04)		958	−0.22	(−0.37, −0.07)	*
2002–2006	496	−0.39	(−0.60, −0.17)	*	1,812	−0.20	(−0.31, −0.08)	*
2008–2010	382	−0.46	(−0.71, −0.21)	*	1,228	−0.24	(−0.37, −0.10)	*
Fine motor index
1998–2000	340	0.13	(−0.03, 0.29)		958	−0.05	(−0.14, 0.04)
2002–2006	496	−0.05	(−0.18, 0.07)		1,812	−0.09	(−0.15, −0.03)	*
2008–2010	382	−0.13	(−0.27, 0.01)		1,228	−0.10	(−0.17, −0.03)	*
Gross motor index
1998–2000	340	−0.14	(−0.46, 0.18)		958	−0.27	(−0.45, −0.09)	*
2002–2006	496	−0.27	(−0.51, −0.04)	*	1,812	−0.31	(−0.44, −0.19)	*
2008–2010	382	−0.40	(−0.68, −0.12)	*	1,228	−0.34	(−0.49, −0.19)	*
Pain
1998–2000	340	−0.26	(−0.36, −0.16)	*	958	−0.17	(−0.23, −0.11)	*
2002–2006	496	−0.25	(−0.33, −0.17)	*	1,812	−0.19	(−0.23, −0.15)	*
2008–2010	382	−0.25	(−0.34, −0.16)	*	1,228	−0.17	(−0.23, −0.12)	*
Pain restrict
1998–2000	340	−0.22	(−0.32, −0.11)	*	958	−0.14	(−0.20, −0.08)	*
2002–2006	496	−0.24	(−0.32, −0.15)	*	1,812	−0.20	(−0.25, −0.16)	*
2008–2010	382	−0.31	(−0.41, −0.22)	*	1,228	−0.20	(−0.25, −0.14)	*

∗Statistically significant < 0.05.