Evidence-based On-call

Exacerbation of Chronic Obstructive Pulmonary Disease

Clinical features

Ask about smoking ^a

and how much for how long ^a

Why?

Inhaling cigarettes increases the risk of being admitted to hospital with COPD ^a
Remember COPD can occur in life-long non-smokers (5.1%: 95% CI: 4.7% to 5.4%) ^b

Heavy smoking makes COPD more likely

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
suspected COPD ^a (pre-test probability: 39%)	COPD (spirometry)	smoking history > 40 pack-years	11.6	87%	0.90	35%
suspected COPD ^a (pre-test probability: 39%)	COPD (spirometry )	ever smoked	1.2 (1.1 to 1.4)	43%	0.23 (0.08 to 0.64)	13%