Table 2

Regression of hospital charges on hospital and market characteristics for 10 common blood tests performed in California hospitals

Multiplicative increase for each unit change in predictor
	Basic metabolic panel	Complete CBC with/automated differential WCC	Compre-hensive metabolic panel	Lipid panel	Complete CBC automated	Assay thyroid-stimulating hormone	Assay of ck (cpk)	Assay of troponin quant	Pro-thrombin time	Thrombo-plastin time, partial
Hospital-level characteristics
Ownership
Government	−0.58*	−0.37*	−0.45*	−0.26**	−0.34*	−0.33**	−0.18	−0.28**	−0.38**	−0.46*
Non-profit	ref	ref	ref	ref	ref	ref	ref	ref	ref	ref
For-profit	0.41*	0.17	0.50*	0.17	0.07	−0.10	0.17	0.15	0.05	0.21
Teaching hospital	−0.38**	−0.60*	−0.45**	−0.35**	−0.64*	−0.44*	−0.67*	−0.65*	−0.67*	−0.57*
Rural MSA	0.25	0.17	0.11	0.11	0.14	−0.01	0.02	0.14	0.24	0.23
Number of licensed beds	0.00	0.00	0.00	0.00	0.00**	0.00	0.00**	0.00	0.00	0.00
Patient mix
Proportion medicare	0.12	0.21	0.25	0.33	0.28	−0.21	0.64	−0.06	0.05	0.12
Proportion medicaid	0.94**	0.81	0.87	0.95*	0.77	0.80	0.35	0.58	1.20**	0.74
Case mix (severity)
Quartile 2	0.31**	0.32**	0.31**	0.29	0.15	0.32**	0.07	0.24	0.34	0.21
Quartile 3	0.16	0.15	0.16	0.26	0.06	0.30**	0.10	0.26	0.33	0.26
Wage Index	0.82	0.65	0.53	−0.03	0.57	0.18	0.34	0.23	0.62	−0.12
Market-level characteristics
Proportion with out health insurance	2.34	1.03	3.24	−0.72	−2.20	−2.87	−2.04	−1.38	2.11	−0.58
Proportion in poverty	1.36	0.91	−0.78	−0.52	3.49	0.98	2.95	0.06	−0.35	0.04
Herfindal-Hirschman Index
Quartile 2	0.00	−0.15	−0.12	0.01	−0.05	0.00	−0.21	−0.03	−0.18	0.03
Quartile 3	−0.24	0.03	0.02	0.08	−0.20	0.15	−0.28**	−0.04	−0.33	−0.02
Variation explained by the model
R²	20%	15%	21%	12%	13%	16%	13%	14%	15%	14%

*p<0.05; **p<0.10.
CBC, complete blood cell count; ck, creatine kinase; WCC, white cell count.