dos Remedios L V, Weber P M, Feldman R, Schurr D A, Tsoi T G
Arch Intern Med. 1980 Aug;140(8):1045-9. doi: 10.1001/archinte.140.8.1045.
The free thyroxine index (FTI) was used in 2,704 adults to detect unsuspected thyroid dysfunction. Among 2,581 adults found to be clinically euthyroid without thyroid medication, 2,571 had a truly normal FTI (121 to 360) and ten had a falsely abnormal FTI (seven less than 121, three greater than 360). Among 25 subjects with newly diagnosed thyroid dysfunction, there were eight hyperthyroid (prevalence, 0.31%) and 14 hypothyroid (prevalence, 0.50%) subjects. The sensitivity of the FTI was 1.0, and the specificity was 0.996. The predictive value of an abnormal FTI with a prevalence of 0.81% was 67%. The cost to find a new case averaged $127. The annual incidence of symptomatic hyperthyroidism was 0.05%; of hypothyroidism, about 0.08%. We conclude that the FTI is cost-effective for case finding in thyroid dysfunction.
游离甲状腺素指数（FTI）用于2704名成年人，以检测未被怀疑的甲状腺功能障碍。在2581名临床甲状腺功能正常且未服用甲状腺药物的成年人中，2571人的FTI真正正常（121至360），10人的FTI错误异常（7人低于121，3人高于360）。在25名新诊断为甲状腺功能障碍的受试者中，有8名甲状腺功能亢进（患病率0.31%）和14名甲状腺功能减退（患病率0.50%）受试者。FTI的敏感性为1.0，特异性为0.996。患病率为0.81%时，FTI异常的预测值为67%。发现一例新病例的平均成本为127美元。有症状的甲状腺功能亢进的年发病率为0.05%；甲状腺功能减退的年发病率约为0.08%。我们得出结论，FTI在甲状腺功能障碍的病例发现中具有成本效益。
