Clinical features

• asymmetric respiration ^a
• chest dullness on percussion ^a
• decreased breath sounds ^a
• bronchial breathing ^a
• crackles ^{a b}
• egophony ^a

Why?

Abnormal chest findings make pneumonia more likely

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
suspected pneumonia a (pre-test probability: 5%)	pneumonia (chest X-ray)	asymmetric respiration	infinity (3.2 to infinity)	100%	0.96	5%
		dullness to percussion	2.2	10%	0.92	5%
		decreased breath sounds	2.3	11%	0.78	4%
		bronchial breath sounds	3.5	16%	0.90	5%
		crackles	1.6	8%	0.83	4%
		egophony	2.0	10%	0.96	5%

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
attending emergency department with chest pain b (pre-test probability: 20%)	myocardial infarction (ECG and cardiac enzyme changes)	pulmonary crackles on auscultation	2.1 (1.5 to 3.1)	23%	0.76 (0.62 to 0.92)	10%