The editors wish to clarify the equation printed on page 48 of the March/April issue. The text reads: ''For example, if the patient's total serum calcium level is lower than normal (7 mg/dl), but her serum albumin is also low at 3 g/dl (normal 4.4 g/dl), you need to calculate a corrected calcium level. You can do this by using the following formula:

A more thorough mathematical breakdown after the printed equation would be as follows, with calculations within parenthesis done first:

Equation (Uncited)

X = 7 + 0.8 (4.4 - 3)

X = 7 + (0.8)(1.4)

X = 7 + 1.12

X = 8.12.