Investigations

• positive if > 4.0 pmol/l or within reference range (0.9 to 4.0 pmol/l) that is high in relation to calcium

PTH can diagnose and exclude primary hyperparathyroidism

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability	LR- (95% CI)	Post-test Probability
hypercalcaemia c (pre-test probability: 13%)	primary hyperparathyroidism (investigations)	parathyroid hormone	58 (8.3 to 400)	90%	0.0 (0.0 to 0.048)	0%