Evaluation of thyroid function monitoring in people treated with lithium: Advice based on real-world data.

Introduction: Blood test monitoring is essential for the management of lithium treatment and National Institute for Health and Care Excellence guidance recommends 6-monthly serum testing of thyroid function. We examined conformity to these guidelines and the impact of monitoring outside these intervals.

Methods: We extracted serum lithium and thyroid hormone results at one centre between January 2009 and December 2020.