In medicine and statistics, gold standard test is usually diagnostic test or benchmark that is the best available under reasonable conditions. Other times, gold standard is the most accurate test possible without restrictions. Both meanings are different because for example, in medicine, dealing with conditions that would require an autopsy to have a perfect diagnosis, the gold standard test would be the best one that keeps the patient alive instead of the autopsy.
Youâll use intermediate strength (5 T.U.) PPD in a tuberculin syringe that has a 1/2-inch, 26- or 27-gauge needle. Make sure the bevel edge of the needle is facing up, and insert the needle beneath the skin (Figure 1).ouâll use intermediate strength (5 T.U.) PPD in a tuberculin syringe that has a 1/2-inch, 26- or 27-gauge needle. Make sure the bevel edge of the needle is facing up, and insert the needle beneath the skin (Figure 1).
How long do you have to wait to read a tb test. TB skin tests should be read between 48 and 72 hours after the injection when the size of the induration is maximal. Tests read after 72 hours tend to underestimate the size of the induration. ChaCha on! [ Source: http://www.chacha.com/question/how-long-do-you-have-to-wait-to-read-a-tb-test ]