Clinical features

• asymmetric respiration ^a
• dullness to percussion ^a
• decreased breath sounds ^a
• bronchial breathing ^a
• crackles ^a
• aegophony ^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 inf)	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%
		aegophony	2.0	10%	0.96	5%

Note:

• Other clinical features are not particularly helpful at diagnosing pneumonia ^b
• Clinicians agree moderately about dullness to percussion, reduced chest movement, wheeze and crackles, but agree poorly about whispering pectoriloquy and increased tactile fremitus ^b