. Author manuscript; available in PMC: 2014 Oct 1.

Published in final edited form as: J Econ Manag Strategy. 2013 Jul 10;22(3):10.1111/jems.12023. doi: 10.1111/jems.12023

Table 2.

A Vertical integration and length of stay: home health (HHA)

Dep. var: ΔLOS	(1)		(2)	(3)		(4-I)		(4-II)	(5)		(6)
	OLS		OLS Controls	Matched (CEM)		1^st stage IV (logit)		2^nd stage 2SRI	OLS Interaction 1		OLS Interaction 2
*Hosp. vertically int. into home health*	*−0.12 (0.05)*	^**	*−0.07 (0.05)*	*−0.09 (0.05)*	^**			*−0.20 (0.15)*
Other hosp. vert. int. into home health						0.30 (0.04)	^***
Residual from 1^st stage								0.06 (0.06)
*Within firm transfer (VI_HOSP_TX)*									*−0.10 (0.04)*	^**	*−0.09 (0.04)*	^**
VI_HOSP to other HHA (VI_HOSP_EXT)									−0.04 (0.05)
VI_HOSP to non-VI_HHA (VI_EXT_NON)											−0.04 (0.05)
VI_HOSP to other VI_HHA (VI_EXT_VI)											−0.02 (0.07)
Non-VI_HOSP to VI_HHA (VI_HHA_IN)											0.09 (0.06)
Patient controls	N		Y	Y		Y		Y	Y		Y
Hospital controls	N		Y	Y		Y		Y	Y		Y
Market controls	N		Y	Y		Y		Y	Y		Y
Constant	Y		Y	Y		Y		Y	Y		Y
R²/Adj.-R²/Pseudo-R²	0.00		0.04	0.04		0.16		0.04	0.05		0.05
F-test on IV						60
N	399,616		399,616	344,384		2,571		399,616	399,616		399,616

B Vertical integration and length of stay: skilled nursing facility (SNF)

Dep. var: ΔLOS	(1)		(2)		(3)		(4-I)		(4-II)		(5)		(6)
	OLS		OLS Controls		Matched (CEM)		1^st stage IV (logit)		2^nd stage 2SRI		OLS Interaction 1		OLS Interaction 2
*Hosp. vertically int. into SNF*	*−0.27 (0.08)*	^***	*−0.22 (0.06)*	^***	*−0.20 (0.07)*	^***			*−0.64 (0.02)*	^**
Other hosp. vert. int. into home health							0.34 (0.04)	^***
Residual from 1^st stage									0.20 (0.13)
*Within firm transfer (VI_HOSP_TX)*											*−0.37 (0.08)*	^***	*−0.38 (0.08)*	^***
VI_HOSP to other SNF (VI_HOSP_EXT)											−0.04 (0.08)
VI_HOSP to non-VI_SNF (VI_EXT_NON)													−0.03 (0.08)
VI_HOSP to oth. VI_SNF (VI_EXT_VI)													−0.52 (0.20)	^***
Non-VI_HOSP to VI_SNF (VI_SNF_IN)													−0.07 (0.11)
Patient controls	N		Y		Y		Y		Y		Y		Y
Hospital controls	N		Y		Y		Y		Y		Y		Y
Market controls	N		Y		Y		Y		Y		Y		Y
Constant	Y		Y		Y		Y		Y		Y		Y
R²/Adj.-R²/Pseudo-R²	0.00		0.06		0.06		0.08		0.06		0.06		0.06
F-test on IV							72
N	460,761		460,761		397,038		2,571		460,761		460,761		460,761

Standard errors are robust and clustered at the market level.

^***

Significant at 1%,

^**

Significant at 5%,

Significant at 10%

Patient controls include: age, gender, race, 28 controls for patient health characteristics upon admission to the hospital (Elixhauser comorbidities). Hospital controls include: co-location dummy (with home health), ownership form dummies {for-profit, government, not-for-profit}, number of beds, and a dummy for teaching hospital. Market controls include: hospital, home health, and SNF concentration; avg. educational attainment, median household income, % of population over 65 year old, a dummy for metropolitan area, population density, number of hospital beds, number of long-term care hospital beds, number of skilled nursing facilities beds, the percentage of women of child bearing age (% of population that is female aged 15–44), and the HMO enrollment rate.

Standard errors are robust and clustered at the market level.

^***

Significant at 1%,

^**

Significant at 5%,

Significant at 10%

Patient controls include: age, gender, race, 28 controls for patient health characteristics upon admission to the hospital (Elixhauser comorbidities). Hospital controls include: co-location dummy (with SNF), ownership form dummies {for-profit, government, not-for-profit}, number of beds, and a dummy for teaching hospital. Market controls include: hospital, home health, and SNF concentration; avg. educational attainment, median household income, % of population over 65 year old, a dummy for metropolitan area, population density, number of hospital beds, number of long-term care hospital beds, number of skilled nursing facilities beds, the percentage of women of child bearing age (% of population that is female aged 15–44), and the HMO enrollment rate.