Table 6.

Ordinary Least Squares Analysis: The Relationship between Hospital–Physician Affiliations and AMI Patient Inpatient, Outpatient, and Physician Payments, 1993–1997

		Dependent Variables
	Independent Variable: Affiliation Type	Log 90-Day Inpatient Payments	Log 90-Day Outpatient and Physician Payments	Log 90-Day Total Payments
Model 1	Any	.42	1.78	1.11
		(.30)	(1.86)	(1.17)
Model 2	Low	.30	3.36	2.05
		(.31)	(1.82)	(1.17)
	High	−.25	−1.80	−1.23
		(.28)	(1.69)	(1.03)
Model 3	IPA	.21	−2.37	−.80
		(.36)	(1.96)	(1.22)
	PHO	.43	4.49*	3.57*
		(.34)	(1.89)	(1.28)
	MSO	−.33	−.13	−.51
		(.31)	(1.89)	(1.18)
	ISM	−.15	−.99	−1.11
		(.37)	(2.01)	(1.26)
	Foundation	−.07	−3.48	−1.23
		(.38)	(2.06)	(1.33)
	Equity	−.72	.52	1.69
		(.66)	(3.46)	(2.26)
	GPWW	−.42	−.38	.35
		(.46)	(2.82)	(1.60)
N Model 1		1,035,482	51,786	51,441
N Model 2		1,032,507	51,653	51,310
N Model 3		1,003,532	50,189	49,858

Notes: Regressions include hospital fixed effects and regressors listed in Appendix. Coefficients and robust standard errors (in parentheses) reported in percentage points. Stata cluster function used to correct for lack of independence across observations for patients admitted to the same hospital. AMI = acute myocardial infarction; IPA = independent practice association; PHO = physician–hospital organization; MSO = management services organization; ISM = integrated salary model; GPWW = group practice without walls.

^*Significant at p<.05 level.