Table 2.

Correlations between average daily volume of emergency physicians and major outcomes of acute myocardial infarction.

Variables	Major outcomes
	Death within 30 days			ED revisits within 3 days			Readmission within 14 days
	Events	%	P value	Events	%	P value	Events	%	P value
Total number	1,131	6.40		130	0.74		178	1.01
Average daily volume of emergency physicians			0.716			0.293			0.376
≤ Q1	299	6.42		26	0.56		42	0.90
Q1 ~ Q2	295	6.12		38	0.79		43	0.89
Q2 ~ Q3	293	6.71		39	0.89		53	1.21
> Q3	244	6.40		27	0.71		40	1.05
PCI service model			< 0.001			0.232			0.032
Non-24-h	883	6.78		102	0.78		144	1.11
24-h	248	5.34		28	0.60		34	0.73
Gender			< 0.001			0.268			0.442
Female	342	11.80		26	0.90		33	1.14
Male	789	5.34		104	0.70		145	0.98
Age (years)			< 0.001			< 0.001			0.034
< 45	45	2.39		7	0.37		13	0.69
45–54	95	2.44		25	0.64		28	0.72
55–64	188	3.79		32	0.65		49	0.99
65–74	252	7.01		20	0.56		40	1.11
75–84	338	13.90		27	1.11		34	1.40
≧85	213	23.80		19	2.12		14	1.56
Mean ± SD	72.30 ± 13.67			66.66 ± 14.80			65.52 ± 13.82
CCI score1			< 0.001			0.019			0.004
0	241	3.49		34	0.49		48	0.69
1	322	6.06		41	0.77		56	1.05
2	185	8.94		22	1.06		24	1.16
3	131	8.95		13	0.89		21	1.43
≧4	252	13.26		20	1.05		29	1.53
Monthly salary (NTD)			< 0.001			0.999			0.067
≦17,280	350	8.16		32	0.75		41	0.96
17,281–22,080	192	7.31		19	0.72		26	0.99
22,081–36,300	415	6.14		50	0.74		83	1.23
≧36,301	174	4.36		29	0.73		28	0.70
Urbanization level			< 0.001			0.002			0.004
Level 1	193	5.25		13	0.35		17	0.46
Level 2	338	6.04		36	0.64		60	1.07
Level 3	191	5.57		27	0.79		40	1.17
Level 4	208	7.57		30	1.09		31	1.13
Level 5–7	201	9.08		24	1.08		30	1.36
Other catastrophic illness			< 0.001			0.092			0.084
No	976	5.90		117	0.71		161	0.97
Yes	155	13.72		13	1.15		17	1.50
MI severity			< 0.001			0.296			0.488
1 blood vessel	887	5.73		110	0.71		159	1.03
2 blood vessels	220	11.06		20	0.91		19	0.87
≥ 3 blood vessels	24	12.24		-	-		-	-
Coronary stent implantation			< 0.001			0.499			0.234
No	748	5.89		97	0.76		121	0.95
Yes	383	7.73		33	0.67		57	1.15
Triage level			< 0.001			0.501			0.597
Level 1	489	11.81		33	0.80		45	1.09
Level 2	469	4.53		72	0.69		106	1.02
Level 3	161	5.43		25	0.84		27	0.85
Levels 4 & 5	12	6.15		-	-		-	-
Accumulated PCI operator volume			< 0.001			0.232			0.518
≤ Q1	471	10.29		43	0.94		52	1.14
Q1 ~ Q2	236	5.41		25	0.57		41	0.94
Q2 ~ Q3	203	4.62		32	0.73		48	1.09
> Q3	221	5.11		30	0.69		37	0.86
Previous year’s PCI operator volume			< 0.001			0.532			0.811
≤ Q1	463	9.79		41	0.87		46	0.97
Q1 ~ Q2	225	5.10		31	0.70		49	1.11
Q2 ~ Q3	223	5.38		25	0.60		43	1.04
> Q3	220	5.02		33	0.75		40	0.91
Hospital level			< 0.001			0.001			0.012
Medical centers	326	5.25		27	0.43		46	0.74
Regional hospitals	683	7.07		83	0.86		106	1.10
District hospitals	122	6.84		20	1.12		26	1.46
Hospital ownership			0.587			0.705			0.609
Public	339	6.56		40	0.77		49	0.95
Nonpublic	792	6.34		90	0.72		129	1.03
Previous year’s PCI institutional volume			< 0.001			0.009			0.094
≤ Q1	344	7.29		39	0.83		59	1.25
Q1 ~ Q2	309	7.18		44	1.02		47	1.09
Q2 ~ Q3	254	5.87		29	0.67		40	0.92
> Q3	224	5.20		18	0.42		32	0.74

¹Myocardial infarction was excluded from CCI score calculation.