Table 1

Patient characteristics for patients in the development (with and without exclusions), internal and external validation sets and crude 30-day mortality rates. Results for the internal and external validation cohorts were calculated after the exclusion of missing variables required for completing the risk score

		Development set (without exclusions)		Development set (with exclusions)		Internal validation set		External validation set
		n	%	n	%	n	%	n	%
Total count		6779		6522		3290		3230
Age	Mean±SD	62.6±11.5		62.5±11.6		62.3±11.6		61.8±11.6
Age	Missing	0	0	0	0	–	–	–	–
Sex	Male	4856	71.6	4682	71.8	2358	71.7	2360	73.1
	Female	1923	28.4	1840	28.2	932	28.3	870	26.9
	Missing	0	0	0	0	–	–	–	–
Cardiogenic shock	Yes	63	0.9	57	0.9	23	0.7	56	1.7
	No	6642	98	6465	99.1	3267	99.3	3174	98.3
	Missing	74	1.1	0	0	–	–	–	–
Diabetes mellitus	Yes	955	14.1	934	14.3	473	14.4	675	20.9
	No	5701	84.1	5588	85.7	2817	85.6	2555	79.1
	Missing	123	1.8	0	0	–	–	–	–
History of renal disease	Yes	106	1.6	103	1.6	36	1.1	113	3.5
	No	6531	96.3	6419	98.4	3254	98.9	3117	96.5
	Missing	142	2.1	0	0	–	–	–	–
Previous MI	Yes	1841	27.2	1784	27.4	907	27.6	828	25.6
	No	4165	61.4	4039	61.9	2051	62.3	2263	70.1
	Missing	773	11.4	699	10.7	332	10.1	139	4.3
Urgency	Elective	2164	31.9	2095	32.1	996	30.3	992	30.7
	Urgent	2171	32.0	2135	32.7	1114	33.9	894	27.7
	Emergent	2444	36.1	2292	35.1	1180	35.9	1344	41.6
	Missing	0	0	0	0	–	–	–	–
30-daymortality	Dead	171	2.5	153	2.3	75	2.3	64	2.0
	Alive	6608	97.5	6369	97.7	3215	97.7	3166	98.0
	Missing	0	0	0	0	–	–	–	–

MI, myocardial infarction.