Table 3.

Health Care Utilization and Expenditures, by DCG Category, HDHP versus Controls (Difference in Differences Coefficients)

	Probability of Any Use/Expenditure	Level of Use¶	Expenditures¶
DCG category 1†
Total outpatient care∥	−.15	—	−0.25
Primary care physician	−.35	−0.24	−0.12
Specialty physician	.31	0.12	0.05
Outpatient	.08	−0.23	−0.33
Emergency room	−.88*	−1.38	−0.68
Prescription drugs	.13	−0.17	0.24
Subcategories of prescription drugs
Preferred (brand)	.63*	0.37	0.15
Nonpreferred (brand)	−.04	0.68	0.60
Generic	.02	−0.26	−0.16
Essential	.41	0.07	0.58
Discretionary	.35	−0.27	−0.57
DCG category 2‡
Total outpatient care∥	−.24	—	0.83**
Primary care physician	−.14	−0.57**	−0.28
Specialty physician	.75	−0.14	−0.03
Outpatient	−.03	−0.65	0.69
Emergency room	−.76	−0.06	−0.11
Prescription drugs	.96	0.42*	0.53
Subcategories of prescription drugs
Preferred (brand)	.12	0.75*	0.80
Nonpreferred (brand)	−.02	0.46	0.25
Generic	1.15**	0.68**	0.63
Essential	.88	0.60	−0.19
Discretionary	.47	0.38	−0.01
DCG category 3 or higher§
Total outpatient care∥	.99	—	−0.08
Primary care physician	1.16	−0.32	−0.08
Specialty physician	.99	0.32	0.35
Outpatient	−.53	−0.14	−0.15
Emergency room	−.003	−0.77	−0.87
Prescription drugs	1.74	0.04	−0.25
Subcategories of prescription drugs
Preferred (brand)	−.16	−0.30	0.01
Nonpreferred (brand)	1.40**	−0.21	−0.09
Generic	2.25*	−0.003	−0.29
Essential	−.55	0.15	−0.11
Discretionary	2.16**	0.008	−0.88

^†Expected cost=0.02–0.54 × average cost.

^‡Expected cost=0.54–2.69 × average cost.

^§Expected cost (≥2.7 × average cost).

^¶Conditional on any level of use/expenditures.

^∥Sum of all expenditures in PCP, specialty physician, outpatient, ER, and prescription drugs.

^*Significant at the p≤.05 level

^**Significant at the p≤.01 level.