Table 3.

Procedural/admission characteristics of study groups after propensity score matching

	2OPMT group		CSWWD group		Std. Diff.*
N	5,338	100%	5,338	100%
Primary diagnosis group, N/%
Atherosclerotic heart disease of native coronary artery	2,691	50.40%	2,673	50.10%	0.007
Chronic disease of rheumatic origin	196	3.70%	218	4.10%	−0.021
Non-ST elevation myocardial infarction	1,088	20.40%	1,077	20.20%	0.005
Nonrheumatic valve disorder	807	15.10%	812	15.20%	−0.003
Other Circulatory Disease	556	10.40%	558	10.50%	−0.001
Aortic procedure, N/%	349	6.50%	353	6.60%	−0.003
Valve repair/replacement procedure, N/%	1,333	25.00%	1,379	25.80%	−0.020
Number of bypasses, N/%
0 (non-CABG procedure)	949	17.80%	986	18.50%	−0.018
1	221	4.10%	226	4.20%	−0.005
2	831	15.60%	847	15.90%	−0.008
3	1,705	31.90%	1,730	32.40%	−0.010
4	1,222	22.90%	1,140	21.40%	0.037
5	410	7.70%	409	7.70%	0.001
Internal mammary artery bypass graft, N/%	4,013	75.20%	3,984	74.60%	0.013
History of cardiac surgery, N/%	1,212	22.70%	1,198	22.40%	0.006
Admission type, N/%
Elective	2,924	54.80%	2,989	56.00%	−0.024
Emergency	1,246	23.30%	1,233	23.10%	0.006
Information Not  Available	40	0.70%	39	0.70%	0.002
Trauma Center	3	0.10%	2	0.00%	0.009
Urgent	1,125	21.10%	1,075	20.10%	0.023

Std. Diff. standardized mean difference

*A standardized mean difference with an absolute value ≤ 0.10 is considered to balanced