Knowledge and Evaluation Research Unit, Department of Medicine, Mayo Clinic, Rochester, MN 55902, USA.
Division of Endocrinology, Diabetes, Metabolism and Nutrition, Department of Medicine, Mayo Clinic, Rochester, MN 55902, USA.
J Clin Endocrinol Metab. 2024 Jan 18;109(2):e765-e772. doi: 10.1210/clinem/dgad517.
Levothyroxine is one of the most prescribed medications in the United States.
This study explores the appropriateness of levothyroxine prescriptions.
A retrospective multicenter study was conducted on adult patients who were prescribed levothyroxine for the first time between 2017 and 2020 at three academic centers in the United States. We classified each case of levothyroxine initiation into one of three mutually exclusive categories: appropriate (clinically supported), indeterminate (clinically unclear), or nonevidence based (NEB, not clinically supported).
A total of 977 participants were included. The mean age was 55 years (SD 19), there was female (69%) and White race predominance (84%), and 44% had possible hypothyroid symptoms. Nearly half of the levothyroxine prescriptions were considered NEB (528, 54%), followed by appropriate (307, 31%) and indeterminate (118, 12%). The most common reason for NEB prescription was an index thyrotropin (TSH) value of less than 10 mIU/L without previous TSH or thyroxine values (131/528, 25%), for appropriate prescription, was overt hypothyroidism (163/307, 53%), and for an indeterminate prescription was a nonconfirmed subclinical hypothyroidism with TSH greater than or equal to 10 mIU/L (no confirmatory testing) (51/118, 43%). In multivariable analysis, being female (odds ratio [OR]: 1.3; 95% CI, 1.0-1.7) and prescription by a primary care provider (OR: 1.5; 95% CI, 1.2-2.0) were associated with NEB prescriptions.
There is a considerable proportion of NEB levothyroxine prescriptions. These results call for additional research to replicate these findings and to explore the perspective of those prescribing and receiving levothyroxine.
左甲状腺素是美国最常开的药物之一。
本研究探讨左甲状腺素处方的适宜性。
这是一项在美国三个学术中心进行的回顾性多中心研究，共纳入 2017 年至 2020 年首次开左甲状腺素的成年患者。我们将每个左甲状腺素起始病例分为以下三个互斥类别之一：适宜（有临床依据支持）、不确定（临床依据不明确）或无证据基础（无临床依据支持）。
共纳入 977 名参与者。平均年龄为 55 岁（标准差 19），女性（69%）和白种人（84%）居多，44%有疑似甲状腺功能减退症状。近一半的左甲状腺素处方被认为是无证据基础（528 例，54%），其次是适宜（307 例，31%）和不确定（118 例，12%）。无证据基础处方最常见的原因是促甲状腺激素（TSH）指数小于 10 mIU/L 且无既往 TSH 或甲状腺素值（131/528，25%），适宜处方的原因是显性甲状腺功能减退（163/307，53%），不确定处方的原因是 TSH 大于或等于 10 mIU/L 的非确诊亚临床甲状腺功能减退（无确认性检测）（51/118，43%）。多变量分析显示，女性（比值比[OR]：1.3；95%置信区间[CI]：1.0-1.7）和初级保健医生处方（OR：1.5；95%CI：1.2-2.0）与无证据基础处方相关。
无证据基础的左甲状腺素处方比例相当大。这些结果呼吁开展更多研究来复制这些发现，并探讨开处方者和接受者的观点。
