Prognosis

• neck or back stiffness ^a
• seizures ^b
• altered mental state ^{b c}
• focal neurological signs ^a
• stenosis of intracranial arteries ^a
  
• haemorrhagic diathesis ^a
• hypotension ^b
  
• anaemia on admission (Hb < 11 g/dl) ^b

Altered mental state and seizures increase the risk of dying or neurological disability

Patient	Prognostic Factor	Outcome	CER	OR (95% CI)	NNF+ (95% CI)
patients aged 60 or more with meningitis a	neck or back stiffness  independent	Death at uncertain duration	38%	2.3 (1.6 to 3.4)	4 (3 to 45)
community-acquired meningitis b	hypotension independent	Death or neurological disability at uncertain duration	35%	2.75 (1.22 to 6.18)	5 (2 to 30)
community-acquired meningitis b	seizures independent	Death or neurological disability at uncertain duration	35%	4.42 (1.56 to 12.5)	4 (2 to 17)
community-acquired meningitis b	altered mental status independent	Death or neurological disability at uncertain duration	10%	6.56 (1.71 to 25.2)	7 (6 to 16)
community-acquired meningitis a	stenosis of intracranial arteries independent	Death or severe disability at weeks	55%	7.4 (1.1 to 45.6)	3 (2 to 43)

• Increasing age and anaemia increase the risk of dying or have severe disability. ^a

Meningococcal disease: frank bleeding and focal neurological signs increase the risk of dying, and preadmission antibiotics reduce it

Patient	Prognostic Factor	Outcome	CER	OR (95% CI)	NNF+ (95% CI)
proven meningococcal disease a	pre-admission antibiotic independent	death at 7 days	11%	0.07 (0.02 to 0.34)	-10 (-15 to -10)
	focal neurologic signs independent	death at 7 days	5.0%	2.29 (1.60 to 3.26)	3 (2 to 10)
	haemorrhagic diathesis independent	death at 7 days	4.1%	2.21 (1.37 to 3.57)	1 (1 to 2)