Clinical features

Why?

• Chest pain, which began 48 hours or more ago makes a myocardial infarction more likely. ^a

Episodes of chest pain for over 1 year makes coronary artery disease more likely

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
intermittent chest pain referred for investigation c (pre-test probability: 67%)	coronary artery disease (angiography and exercise test)	chest pain for over 1 year	infinity (3.5 to infinity)	100%	0.37 (0.23 to 0.59)	43%

Constant pain makes a myocardial infarction more likely

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
anterior chest pain b (pre-test probability: 12%)	myocardial infarction (cardiac enzymes, ECG)	constant pain	1.7 (1.3 to 2.1)	19%	0.58 (0.41 to 0.82)	8%