McMahon score = sum of points present at admission.

Variable	Admission criterion	Points
Age	≤50 years	0
Age	>50 to ≤70 years	1.5
Age	>70 to ≤80 years	2.5
Age	>80 years	3
Sex	Female	1
Creatinine	<1.4 mg/dL (<124 µmol/L)	0
Creatinine	1.4–2.2 mg/dL (124–194 µmol/L)	1.5
Creatinine	>2.2 mg/dL (>194 µmol/L)	3
Calcium	<7.5 mg/dL (<1.875 mmol/L)	2
Creatine kinase	>40,000 U/L	2
Cause	Other than seizure, syncope, exercise, statin use, or myositis	3
Phosphate	≤3.9 mg/dL (≤1.29 mmol/L)	0
Phosphate	4.0–5.4 mg/dL (1.30–1.74 mmol/L)	1.5
Phosphate	>5.4 mg/dL (>1.74 mmol/L)	3
Bicarbonate	<19 mEq/L (<19 mmol/L)	2

Possible score range: 0–19 points.

McMahon Score for Rhabdomyolysis