Clinical features

Why?

A history of heart failure makes left ventricular failure more likely

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
suspected heart failure a (pre-test probability: 6%)	LV ejection fraction < 50% (echocardiogram)	history of heart failure	- (20 to infinity)	100%	0.60 (0.54 to 0.66)	51%

A history of congestive heart disease increases the risk for further episodes

Patient	Prognostic Factor	Outcome	CER	OR (95% CI)	NNF+ (95% CI)
frail elderly a	history of congestive heart disease independent	congestive heart disease at 12 months	15%	7.0 (2.9 to 17)	2 (2 to 5)