Table 1.

Hospital characteristics before and after propensity score matching, ACO versus non-ACO hospitals

	Before matching			After matching			Weighted standardized difference
	ACO	Non-ACO	P-value	ACO	Non-ACO	P-value	Before matching	After matching
Number of hospitals	427	3,090		427	1,529
Number of patients	341,675	1,861,428		341,675	1,024,090
Geographic region (%)
Northeast	26.7	13.8	< 0.001	26.7	29.7	0.336	0.3244	−0.0748
West	12.6	20.8	< 0.001	12.6	15.7	0.206	−0.2191	−0.0813
Midwest	35.4	27.3	0.001	35.4	32.3	0.338	0.1748	0.0672
South	25.3	38.1	< 0.001	25.3	22.4	0.324	−0.2782	0.0625
Procedure volume quintile (%)
1st	10.5	21.4	0.935	10.5	10.7	0.935	−0.3002	−0.0047
2nd	14.1	20.8	0.001	14.1	12.1	0.392	−0.1779	0.0523
3rd	18.3	20.2	0.343	18.3	19.4	0.677	−0.0497	−0.0283
4th	23.0	19.5	0.099	23.0	26.0	0.296	0.0832	−0.0753
5th	34.2	18.0	< 0.001	34.2	31.8	0.458	0.3742	0.0553
Technology hospital (%)	71.8	46.3	< 0.001	71.8	70.4	0.639	0.5596	0.0306
Profit status (%)
For-Profit	4.5	22.8	< 0.001	4.5	4.6	0.962	−0.5669	−0.0020
Non-Profit	88.0	60.5	< 0.001	88.0	88.9	0.677	0.6774	−0.0218
Other	7.5	16.7	< 0.001	7.5	6.5	0.581	−0.2913	0.0299
Bed size (%)1
< 250 beds	55.0	73.571	<0.001	55.0	58.6	0.270	−0.4053	−0.0795
> 250 to < 500 beds	30.9	19.626	<0.001	30.9	29.1	0.547	0.2738	0.0438
> 500 beds	14.1	6.8	<0.001	14.098	12.3	0.415	0.2466	0.0622
Teaching hospital (%)1	53.2	34.0	<0.001	53.197	49.6	0.266	0.4231	0.0784
Nurse ratio1	8.9	9.8	0.016	8.8655	8.8	0.946	−0.1441	0.0034
% Medicaid days1,2	19.1	18.9	0.729	19.14	18.4	0.362	0.0181	0.0594

¹Variables not used in propensity score matching.

²Medicaid patient-days normalized to total patient-days