Well stated. I'm a retired neurosurgical anesthesiologist who relied on accurate blood test results to manage major intracranial procedures. No way would I accept a finger-stick hemoglobin/hematocrit as the basis on which to decide on the need for blood transfusion. Why? Because as a medical intern I did them routinely, because I had to get a number to present at morning rounds and even our excellent STAT Lab (LAC-USC Medical Center in Los Angeles) sometimes couldn't turn around a properly drawn venous sample in time. Because it was often difficult to get sufficient blood volume from a finger-stick to fill even the tiny glass capillary tubes we used to "spin a 'crit" in a centrifuge, I would occasionally squeeze a patient's fingertip to enhance blood flow. Those results were sometimes wildly at variance with later venous samples from the same patient. Why? Because they were diluted with interstitial fluid along with capillary blood, the result of my manual pressure on the fingertip.