Table 2 Clinical codes of patients in the database.

		n		%
Myocardial infarction		908		16.3
Diabetes		71		1.3
Fits/convulsions		332		5.9
Non‐specific		154		2.8
Collapse, faint, unresponsive		217		3.9
Cardiac disease (confirmed)		1488		26.7
Cardiac chest pain		19		0.3
Respiratory disease (confirmed)		451		8.1
Respiratory symptoms		18		0.3
Serious haemorrhage		72		1.3
Cerebrovascular/CNS (confirmed)		416		7.5
Non cardiac chest pain		451		8.1
Poisoning		342		6.1
Asphyxia		18		0.3
Other		626		11.2