Fig. 4.

Breakdown of Add-on Order Volumes by Category of Testing. The categories of testing are: Clinical Chemistry (performed in core laboratory), Hematology/Coagulation and Urinalysis (performed in core laboratory), Critical Care (blood gases, whole blood electrolytes, and other testing performed in satellite critical care laboratories), Reference Laboratory (testing referred to outside laboratories), and Miscellaneous (all testing not fitting into other categories)