Background:

There has been a trend for increased prescribing of levothyroxine (LT4) in many countries, including the United States. Several different factors have been suggested to be the cause of this practice pattern. These factors include increased size of the United States population, more diagnosis of hypothyroidism, more treatment of minimally elevated thyroid-stimulating hormone (TSH) levels, more use of LT4 in older patients, and use of LT4 for treatment of euthyroid patients with non-thyroidal conditions.

Methods:

The electronic databases of the MedStar Health system operating in the Washington, DC and Maryland areas were interrogated to determine the number of patients who were being prescribed levothyroxine during the time period 2008–2016, the number of prescriptions supplied to these individuals, the associated diagnosis, and whether the prescriptions were new or existing prescriptions. Regression analyses were also performed to determine the prescribing trends during this time period.

Results:

Although the annual number of levothyroxine prescriptions increased during this time period, the percentage of patients in the database receiving levothyroxine for hypothyroidism initially increased and then decreased over time (2.5% to 3.2% to 2.5%). The percentage of prescriptions written for patients who did not appear to carry a diagnosis of hypothyroidism steadily declined (3.5% to 1.0%). Although the percentage of patients with existing prescriptions for hypothyroidism initially increased and then were maintained at steady levels (1.4% to 2.4% to 2.2%), a smaller percentage of patients with existing prescriptions were documented over time when there was no diagnosis of hypothyroidism (1.45% to 0.89%). The percentage of patients with new prescriptions declined over time for all groups. The number of annual 90-day period prescriptions increased over the time for patients with a diagnosis of hypothyroidism, but down-trended starting over the latter part of the time period for those patients without a diagnosis of hypothyroidism.

Conclusion:

Taken together, these data suggest that there may be a stabilization, and even a down-trend in levothyroxine prescribing with the MedStar system. The decrease in levothyroxine prescribing appears to be accounted for by less use of levothyroxine without an established diagnosis of hypothyroidism, and less initiation of new prescriptions.

中文翻译：

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左甲状腺素处方趋势可能表明处方呈下降趋势。

背景：

包括美国在内的许多国家都有增加左甲状腺素 (LT4) 处方的趋势。有几个不同的因素被认为是这种实践模式的原因。这些因甲状腺疾病。

方法：

询问了在华盛顿特区和马里兰州地区运行的 MedStar 健康系统的电子数据库，以确定 2008-2016 年期间服用左旋甲状腺素的患者数量、提供给这些人的处方数量、相关诊断，以及处方是新处方还是现有处方。还进行了回归分析以确定这段时间内的处方趋势。

结果：

尽管在此期间每年开出左旋甲状腺素处方的数量有所增加，但数据库中因甲状腺功能减退而接受左旋甲状腺素的患者比例最初增加，然后随着时间的推移而下降（2.5% 至 3.2% 至 2.5%）。为似乎没有诊断出甲状腺功能减退症的患者开出的处方比例稳步下降（3.5% 至 1.0%）。尽管有现有处方治疗甲状腺功能减退症的患者比例最初增加，然后保持在稳定水平（1.4% 至 2.4% 至 2.2%），但随着时间的推移，在没有诊断出甲状腺功能减退症的情况下，随着时间的推移记录了现有处方的患者比例较小。 1.45% 至 0.89%）。所有组的新处方患者的百分比都随着时间的推移而下降。

结论：

综上所述，这些数据表明，使用 MedStar 系统开出的左甲状腺素处方可能会趋于稳定，甚至呈下降趋势。左甲状腺素处方减少的原因似乎是在未确诊甲状腺功能减退的情况下使用较少的左甲状腺素，以及较少开始新处方。