Clinical features

Why?

Lack of neck stiffness does not rule out meningitis

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
recent-onset headache and fever b (pre-test probability: %)	CSF pleocytosis ( 5 or more white cells per mm 3 of CSF )	neck stiffness	- (1.1 to infinity)	100%	0.85 (0.75 to 0.98)	59%

• Neck stiffness is common in elderly patients without meningitis (35%). ^b