Investigations

• Calculate the corrected calcium
  • corrected calcium (mmol/L) = uncorrected calcium (mmol/L) + 0.02 x (40-albumin) ^a

Why?

A calcium level ≥3.50 mmol/l makes malignancy more likely

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability
hypercalcaemia c (pre-test probability: 47%)	malignancy (hospital records)	calcium ≥3.50 mmol.l	5.7 (2.9 to 11)	84%
		3.00 to 3.49 mmol/l	1.7 (1.2 to 2.5)	60%
		<3.00 mmol/l	0.63 (0.54 to 0.73)	36%