Investigations

• blood count ^c

Why?

• A white cell count > 14.4 x 10⁹/ml makes a pneumococcal infection more likely ^c
• Leukopenia ^b or a haematocrit < 30% increases the risk of dying in the next month ^a

Leukopenia increases the risk of dying

Patient	Prognostic Factor	Outcome	CER	OR (95% CI)	NNF+ (95% CI)
community-acquired pneumonia b	leukopenia independent	death at 30 days	14%	2.5 (1.6 to 3.7)	13 (7 to 100)