J Clin Endocrinol Metab. 2022 Apr 26:dgac215. doi: 10.1210/clinem/dgac215. Online ahead of print.
CONTEXT: Many patients with hypothyroidism receive suboptimal treatment that may impact hospital outcomes.
OBJECTIVE: To identify differences in hospital outcomes between patients with and without hypothyroidism.
DESIGN: A retrospective cohort study, using the propensity score-based fine stratification method to balance covariates.
SETTING: A large, US-based, commercial claims database from January 1, 2008 to December 31, 2015.
PARTICIPANTS: Participants included patients 64 years and younger who had a thyrotropin (TSH) level collected prior to a hospital admission. Covariates included age, sex, US region, type of admission, year of admission, and comorbidities.
EXPOSURE: Clinical hypothyroidism, which was divided into 4 subgroups based on pre-hospitalization TSH level: low (TSH <0.40 mIU/L), normal (TSH 0.40 - 4.50 mIU/L), intermediate (TSH 4.51 - 10.00 mIU/L), and high (TSH >10.00 mIU/L).
MAIN OUTCOMES MEASURES: length of stay (LOS), in-hospital mortality, and readmission outcomes.
RESULTS: A total of 43,478 patients were included in the final study population, of whom 8,873 had a diagnosis of hypothyroidism. Those with a high pre-hospitalization TSH level had a LOS that was 1.2 days longer (95% CI [1.1 - 1.3]; p = 0.003), a 49% higher risk of 30-day readmission (RR 1.49, 95% CI [1.20 - 1.85]; p <0.001), and 43% higher rate of 90-day readmission (RR 1.43, 95% CI [1.21 - 1.67]; p <0.001) compared to balanced controls. Patients with normal TSH levels exhibited decreased risk of in-hospital mortality (RR 0.46, 95% CI [0.27 - 0.79]; p = 0.004) and 90-day readmission (RR 0.92, 95% CI [0.85 - 0.99]; p = 0.02).
CONCLUSIONS: The results suggest that suboptimal treatment of hypothyroidism is associated with worse hospital outcomes, including longer LOS and higher rate of readmission.