Total protein excretion can be measured in a 24-hour collection or can be estimated by the protein / creatinine ratio, which, in a random urine sample, correlates well with values in g/1.73 m 2 BSA (body surface area) from a 24-hour collection (eg, 400 mg / dL protein and 100 mg / dL creatinine in a random sample equal 4 g/1.73 m 2 in a 24-hour collection).