Table 2.

Determinants of the Percentage of Physician Earnings Based on Individual Productivity: Productivity-based Salary (Medical Groups) and Fee-for-Service (IPAs)

	Medical Groups		IPAs
	Primary Care	Specialty Care	Primary Care	Specialty Care
HMO Market Penetration, 21–30%	−13.21**	−12.97**	−39.36***	−8.27
	(5.59)	(5.25)	(8.52)	(7.67)
HMO Market Penetration, 31–45%	−17.00***	−16.90***	−23.06***	−18.80**
	(5.33)	(5.10)	(8.77)	(7.86)
HMO Market Penetration, Greater Than 45%	−12.37**	−21.10***	−41.66***	−26.08***
	(5.80)	(5.50)	(8.23)	(7.43)
Number of Physicians	−0.017**	−0.016**	0.010*	0.013***
	(0.007)	(0.006)	(0.005)	(0.005)
Multispecialty	2.01	29.11***	2.77	34.93***
	(5.54)	(4.95)	(10.64)	(11.45)
Owned by Hospital or HMO	−19.54***	−23.75***	3.99	2.12
	(4.22)	(4.15)	(7.09)	(6.21)
Age of Organization	0.233***	0.212***	0.405	−0.190
	(0.087)	(0.082)	(0.468)	(0.400)
Intercept	67.27	46.86	59.29	48.39
	(6.48)	(5.59)	(11.58)	(13.14)
Adjusted R2	0.14	0.22	0.11	0.12
N	412	423	215	206

Note: Standard errors in parentheses. Sample sizes differ because organizations without primary care physicians are not included in regressions for primary care payment method, and analogously for the specialist payment regressions.

^*=p<.10;

^**=p<.05;

^***=p<.01.