Actually, that paper states that the standard deviation from finger pinpricks is about 5% of the mean value of, for example, platelets. The normal range has a

Actually, that paper states that the standard deviation from finger pinpricks is about 5% of the mean value of, for example, platelets. The normal range has a standard deviation of about 25-50% of the mean https://www.nlm.nih.gov/medlineplus/ency/article/003647.htm https://www.nlm.nih.gov/medlineplus/ency/article/003647.htm. So, if anything, this study supports the conclusion that fingerprick tests have clinical utility.