. 2008 Dec;43(6):1931–1951. doi: 10.1111/j.1475-6773.2008.00899.x

Table 4.

Plan Fixed-Effects Estimates (Constant Weight)—CAHPS Measures (Bootstrapped Standard Errors)

Covariate	CAHPS Health Plan Rating		CAHPS Health Care Rating		CAHPS Physician Rating

	HHI	#HMOs	HHI	#HMOs	HHI	#HMOs
HMO HHI	−0.656	NA	−1.185	NA	−2.594^*	NA
	(1.913)	NA	(1.622)	NA	(1.324)	NA
Number of HMOs	NA	−0.225^***	NA	−0.079	NA	−0.058
	NA	(0.078)	NA	(0.062)	NA	(0.054)
HMO penetration	−0.146	0.986	1.645	1.876	0.772	0.599
	(3.431)	(3.381)	(2.313)	(2.294)	(2.011)	(2.068)
Hospital bed HHI	−2.112	−2.467	1.571	1.035	1.101	0.435
	(3.160)	(3.036)	(2.086)	(2.136)	(2.389)	(2.380)
Allows NCQA to report publicly	1.566^***	1.528^***	1.991^***	1.992^***	1.483^***	1.501^***
	(0.538)	(0.484)	(0.404)	(0.409)	(0.386)	(0.384)
1998^†	0.241	0.186	−0.305	−0.293	−1.134^***	−1.121^***
	(0.389)	(0.391)	(0.304)	(0.307)	(0.282)	(0.292)
2000	2.083^***	1.998^***	1.270^***	1.223^***	1.296^***	1.230^***
	(0.291)	(0.297)	(0.260)	(0.271)	(0.220)	(0.203)
2001	4.069^***	4.182^***	2.057^***	2.086^***	1.518^***	1.513^***
	(0.446)	(0.448)	(0.328)	(0.363)	(0.276)	(0.273)
2002	3.231^***	3.040^***	3.821^***	3.679^***	1.748^***	1.534^***
	(0.595)	(0.577)	(0.437)	(0.466)	(0.349)	(0.342)
Constant	57.701^***	59.798^***	68.019^***	68.629^***	72.238^***	72.358^***
	(2.743)	(2.575)	(1.675)	(1.803)	(1.328)	(1.490)
N	1,608	1,610	1,607	1,609	1,606	1,608
Within R²	0.18	0.18	0.27	0.27	0.18	0.18

Significant at 10%

^**

Significant at 5%

^***

Significant at 1%.

Bootstrapped standard errors based on 500 replications.

^†

1999 is the omitted year.

CAHPS, Consumer Assessment of Health Plans Survey; HHI, Herfindahl–Hirschman Index; HMO, health maintenance organization; NCQA, National Committee for Quality Assurance.