Thorson S C, Mincey E K, McIntosh H W, Morrison R T
Br Med J. 1972 Apr 8;2(5805):67-71. doi: 10.1136/bmj.2.5805.67.
Estimation of serum thyroxine concentration in test serum was performed in the presence of test serum itself and expressed as a fraction (Effective Thyroxine Ratio, E.T.R.) of serum thyroxine concentration similarly determined in normal serum. From studies of serum obtained from euthyroid, hyperthyroid, and hypothyroid patients and from euthyroid pregnant women and women taking contraceptive (oestrogen) medication, the E.T.R. estimation has been shown to have a diagnostic accuracy (99%) in defining thyroid status comparable to that shown by the free thyroxine index (98%). Because of the ease and rapidity with which the procedure can be completed, estimation of E.T.R. shows promise as a single, accurate measure of thyroid status.
在测试血清自身存在的情况下测定测试血清中的血清甲状腺素浓度，并表示为在正常血清中类似测定的血清甲状腺素浓度的分数（有效甲状腺素比率，E.T.R.）。通过对甲状腺功能正常、甲状腺功能亢进和甲状腺功能减退患者以及甲状腺功能正常的孕妇和服用避孕药（雌激素）的女性的血清研究表明，E.T.R.测定在定义甲状腺状态方面具有99%的诊断准确性，与游离甲状腺素指数所显示的诊断准确性（98%）相当。由于该程序可以轻松快速地完成，E.T.R.测定有望成为一种单一、准确的甲状腺状态测量方法。
