. Author manuscript; available in PMC: 2022 Jun 1.

Published in final edited form as: Int J Health Econ Manag. 2021 Feb 26;21(2):189–201. doi: 10.1007/s10754-021-09296-4

Table 3:

Regression analysis of association between network statistics and insurance type

					Referral Centrality
	Degree	Normalized Degree	Eigenvector	Clust. Coeff.	Normalized Degree	Eigenvector
Panel A: Unadjusted Results
Patient has HMO	−0.567^*** (0.076)	0.543^*** (0.037)	−0.0003^* (0.00014)	0.011^*** (0.000)	1.273^*** (0.043)	−0.002^*** (0.000)
R-Squared	0.000	0.000	0.000	0.001	0.001	0.000
Panel B: Partially Adjusted Results including demographics, insurer fixed effects, and patient 3-digit ZIP code
Patient has HMO	−0.384^*** (0.085)	0.233^*** (0.041)	0.0002 (0.00015)	0.007^*** (0.000)	0.266^*** (0.045)	−0.001^*** (0.000)
R-Squared	0.035	0.050	0.106	0.031	0.181	0.190
Panel C: Fully Adjusted Results
Patient has HMO	−0.363 ^*** (0.084)	0.177^*** (0.040)	0.0002 (0.00015)	0.007^*** (0.00043)	0.279^*** (0.045)	−0.0014^*** (0.00018)
R-Squared	0.047	0.074	0.110	0.043	0.183	0.193
Number of Observations	984,470	984,470	984,470	978,557	759,149	759,149

Note: Robust standard errors in parentheses.

^*:

p < 0.05,

^**:

p < 0.01,

^***:

p < 0.001 Fully adjusted regressions shown in Panel C include controls for demographics (i.e., age, age squared, sex, an interaction of sex and age), 162 indicator variables for hierarchical condition categories (HCC), insurer fixed effects, and patient 3-digit ZIP code.