Table 2.

Correlation matrix of CCOP characteristics.

	(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)	(11)	(12)
(1) Total accrual	1.000
(2) Treatment accrual	0.860***	1.000
(3) CP/C accrual	0.924***	0.598***	1.000
(4) Number of total trials	0.783***	0.806***	0.623***	1.000
(5) Number of active physicians	0.585***	0.643***	0.436***	0.493***	1.000
(6) Number of components	0.467***	0.565***	0.308***	0.404***	0.439***	1.000
(7) Number of affiliated IRBs	0.401***	0.465***	0.280***	0.266***	0.464***	0.268***	1.000
(8) Number of affiliated IRBs per component	0.557***	0.626***	0.404***	0.386***	0.644***	0.494***	0.890***	1.000
(9) Number of meetings attended	0.404***	0.386***	0.345***	0.345***	0.301***	0.089*	0.450***	0.422***	1.000
(10) Number of affiliated RBs	0.274***	0.257***	0.238***	0.297***	0.228***	0.074	0.047	0.088	0.107**	1.000
(11) Low physician accrual equity (uneven distribution)	0.124***	0.150***	0.083	0.043	0.060	−0.002	0.173**	0.164***	0.009	0.010	1.000
(12) Medium physician accrual equity	−0.027	−0.002	−0.041	0.063	0.040	0.068	−0.106***	−0.066	−0.091*	0.101*	−0.592***	1.000
(13) High physician accrual equity (even distribution)	−0.107**	−0.163***	−0.046	−0.118**	−0.110**	−0.074	−0.072	−0.107**	0.092*	−0.123**	−0.441	−0.463***
(14) Number of treatment trials	0.759***	0.802***	0.588***	0.975***	0.487***	0.416***	0.287**	0.403***	0.352***	0.291***	0.074	0.044
(15) Number of CP/C trials	0.682***	0.654***	0.579***	0.858***	0.406***	0.297***	0.164**	0.271***	0.262***	0.249***	−0.036	0.094*
(16) Hospital competition (1-\HHI)	−0.258***	−0.203***	−0.253***	−0.381**	0.106**	−0.034	0.053	0.033	−0.121**	−0.025	−0.049	0.085
(17) HMO penetration	−0.187***	−0.159***	−0.174***	−0.213**	0.017	−0.057	−0.061	−0.053	−0.108**	−0.039	0.077	0.010
(18) Uninsured penetration	−0.272***	−0.228***	−0.255***	−0.358**	−0.106**	−0.108**	0.135**	0.048	−0.112**	−0.116**	0.182***	−0.146
(19) High proportion of hospitals in MSA with medical school affiliation	−0.023	0.009	−0.042	0.046	−0.063	0.151***	−0.076	−0.075	−0.147***	−0.050	−0.058	−0.004
(20) Medium proportion of MSA hospitals with medical school affiliation	0.113**	0.098*	0.104*	0.082	0.098*	−0.048	0.064	0.069	0.252***	0.093*	−0.094*	0.057
(21) Low proportion of MSA hospitals with medical school affiliation	−0.092*	−0.109**	−0.063	−0.131**	−0.036	−0.105**	0.012	0.006	−0.107**	−0.044	0.033	0.001
(22) State Insurance Mandate	−0.103*	−0.066	−0.112**	−0.053	0.132**	−0.056	0.012	0.089*	−0.029	0.056	−0.012	0.013
(23) 2002–2003	−0.006	−0.127**	0.086	−0.061	0.001	−0.010	−0.026	−0.013	0.045	0.073	−0.060	−0.006
(24) 2004–2005	−0.014	0.132**	−0.120**	0.075	0.012	−0.014	−0.026	−0.019	0.010	0.189***	−0.028	0.079
(25) 2006–2007	−0.070	−0.067	−0.060	0.024	−0.005	0.012	−0.029	−0.008	−0.084	−0.151***	−0.096	0.041
	(13)	(14)	(15)	(16)	(17)	(18)	(19)	(20)	(21)	(22)	(23)	(24)	(25)
(13) High physician accrual equity (even distribution)	1.000
(14) Number of treatment trials	−0.130**	1.000
(15) Number of CP/C trials	−0.065	0.721***	1.000
(16) Hospital competition (1-HHI)	−0.041	−0.373***	−0.320***	1.000
(17) HMO penetration	−0.095*	−0.171***	−0.265***	0.323***	1.000
(18) Uninsured penetration	−0.038	−0.328***	−0.356***	0.268***	0.222***	1.000
(19) High proportion of hospitals in MSA with medical school affiliation	0.062	0.052	0.024	−0.324***	−0.134	−0.129	1.000
(20) Medium proportion of MSA hospitals with medical school affiliation	0.041	0.066	0.102*	0.240	0.071	0.012	−0.520***	1.000
(21) Low proportion of MSA hospitals with medical school affiliation	−0.038	−0.120**	−0.129**	0.087	0.064	0.120**	−0.491***	−0.488***	1.000
(22) State insurance mandate	−0.001	−0.056	−0.035	0.098*	0.192***	0.152***	−0.192***	0.053	0.142***	1.000
(23) 2002–2003	0.073	−0.045	−0.087	0.000	0.042	0.014	0.056	0.004	−0.061	0.047	1.000
(24) 2004–2005	−0.057	0.046	0.127**	−0.008	0.011	0.063	−0.008	−0.032	0.041	0.110**	−0.337***	1.000
(25) 2006–2007	0.060	−0.030	0.144***	−0.010	−0.148***	−0.120**	−0.077	0.010	0.069	0.093*	−0.330**	−0.327***	1.000