Investigations

• blood count ^c

Why?

Anaemia makes giant cell arteritis more likely

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
suspected giant cell arteritis having a temporal artery biopsy c (pre-test probability: 36%)	giant cell arteritis (positive temporal artery biopsy)	anaemia	2.0 (1.3 to 3.2)	53%	0.58 (0.39 to 0.87)	25%