Investigations

• bilateral ^c   temporal artery biopsy ^a in areas of pain or inflammation (this increases the chance of a positive biopsy) ^c

Why?

• Temporal artery biopsy is the reference standard.

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 (diagnostic criteria and follow-up)	temporal artery biopsy	infinity (14 to infinity)	100%	0.18 (0.10 to 0.32)	17%
suspected giant cell arteritis having a temporal artery biopsy c (pre-test probability: 21%)	giant cell arteritis (temporal artery biopsy and follow-up)	temporal artery biopsy at sites of pain or inflammation	6.0 (3.5 to 10)	61%	0.47 (0.33 to 0.67)	11%