Table 5.

Effect of MA Penetration on Length of Hospital Stay

Dep Var: LOS	Full Sample				Trad. Medicare FFS		MA		Commercial
	OLS		IV payment*year		OLS	IV payment * year	OLS	IV payment * year	OLS	IV payment * year
MA Managed	−.0037	−.0030	−.018**	−.0231**	−.00281	−.0309**	−.00783**	−.0216*	−.00625***	−.0186***
Care Penetration	(0.0028)	(0.0023)	(0.0075)	(0.0092)	(0.0033)	(0.014)	(0.0035)	(0.013)	(0.0018)	(0.0053)
Risk Adjusters	No	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Covariates	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Hosp FEs	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Year FEs	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Observations	13,678,534	13,678,534	13,678,534	13,678,534	5,813,942	5,813,942	1,253,227	1,253,227	3,632,805	3,632,805
R-squared	0.013	0.1019	0.013	0.098	0.087	0.087	0.085	0.085	0.108	0.108

Note: LOS is in days. MA Managed Care Penetration is in percentages. Individual level covariates are age, sex, race, and type of insurance. Hospital level covariates are teaching hospital status, for-profit status, and number of beds. County level covariates include population, % in poverty, % unemployed, per capita income, % male, % white, % black, % Hispanic, % pop under 15, % aged 15–19, % aged 20–20, % aged 25–44, % aged 45–64, % aged 65 and older, # of general practitioners per capita, # of specialists per capita, # of surgeons per capita, # of other physicians per capita. Robust standard errors in parentheses (clustered on county).

^***p<0.01,

^**p<0.05,

^*p<0.1.

Data are from Healthcare Cost and Utilization Project’s state inpatient database for NY, MA, AZ, FL, and CA (20% sample) for 1999–2009 and from the Medicare enrollment files for 1998–2009.