Which of the Following Should Be Required of Ambulatory Patients

Which of the following should be required of ambulatory patients to minimize the preanalytical effect of posture on laboratory test results?

A) The patient should be seated for 15 minutes prior to blood collection.
B) The patient should be allowed to stand quietly or be seated for 15 minutes prior to blood collection.
C) The patient should be allowed to stand quietly, be seated, or lie down for 15 minutes prior to blood collection.
D) There should be no restrictions on ambulatory patients.