SHBG and polycystic ovary syndrome: All relevant CPGs supported the use of testosterone (total or free) or the free androgen index (calculated as the ratio is the level of total testosterone divided by the level of sex hormone-binding globulin and multiplied by 100) to diagnose hyperandrogenemia, although there were variations on the value of androstenedione and dehydroepiandrosterone sulphate as routine blood tests to diagnose PCOS.