Table 2: Application of the standard and ECG coding definitions to data for all patients admitted to hospital with acute MI in Alberta between Apr. 1, 2007, and Mar. 31, 2010 (n = 15 148*)

Group; acute MI subtype	Coding definition	Mortality, %	No. of patients
Overall
Standard definition
STEMI	I21.0-3	5.51	5713
Non-STEMI	I21.4x	3.95	9435
ECG definition
STEMI	R94.30	5.42	5530
Non-STEMI	R94.31	3.89	9070
Female
Standard definition
STEMI	I21.0-3	8.79	1525
Non-STEMI	I21.4x	4.82	3174
ECG definition
STEMI	R94.30	8.63	1460
Non-STEMI	R94.31	4.77	3038
Male
Standard definition
STEMI	I21.0-3	4.32	4188
Non-STEMI	I21.4x	3.51	6261
ECG definition
STEMI	R94.30	4.28	4070
Non-STEMI	R94.31	3.45	6032
Age < 65 yr
Standard definition
STEMI	I21.0-3	2.15	3342
Non-STEMI	I21.4x	0.62	4009
ECG definition
STEMI	R94.30	2.20	3266
Non-STEMI	R94.31	0.57	3868
Age ≥ 65 yr
Standard definition
STEMI	I21.0-3	10.25	2371
Non-STEMI	I21.4x	6.41	5426
ECG definition
STEMI	R94.30	10.07	2264
Non-STEMI	R94.31	6.36	5202

Note: ECG = electrocardiogram; MI = myocardial infarction; STEMI = ST-elevation MI.

*For ECG definition n = 14 600 (528 patients had an unspecified abnormal ECG result [R94.38] or missing supplementary R94.3x code, and 20 patients had both the code R94.30 and the code R94.31).