Once started, thyroid hormone replacement is usually continued for life, even in patients who have subclinical hypothyroidism and in whom the benefits of the medication are unclear. Researchers conducted a systematic review and meta-analysis to summarize the clinical outcomes of patients for whom thyroid hormone replacement was discontinued, identify predictors of successful discontinuation, and evaluate the frameworks used to deprescribe thyroid hormone replacement.

Seventeen observational studies that included patients undergoing thyroid hormone discontinuation were eligible for analysis. The studies, which the researchers judged to be at moderate to high risk of bias, included a total of 1,082 patients.

At median five-year follow-up, 37.2% of patients still had normal thyroid function. Patients with overt hypothyroidism were less likely to remain euthyroid than those with subclinical hypothyroidism. Overall, 65.8% of patients restarted thyroid hormone replacement, with patients who had overt hypothyroidism more likely to do so. No studies reported a systematic framework for deprescribing thyroid hormone replacement.

Deprescribing thyroid hormone replacement may be reasonable for patients in whom the benefits don't outweigh the risks, the authors conclude. They recommend a shared decision-making process for doing so, as well as a plan for follow-up.