Hypothyroidism: Its incidence and prevalence in adults older than 55 years of age in an acute rehabilitation unit

Objective: To investigate the incidence and prevalence of hypothyroidism in the acute rehabilitation unit. Design: Retrospective chart review. Setting: Inpatient rehabilitation unit. Patients: Thirty-five men and 91 women older than the age of 55 years (average, 74 years) separated into postsurgical (PS) and nonsurgical (NS) groups. Twenty-two men and 76 women were PS, 21 of whom had a history of hypothyroidism. Thirteen men and 15 women were NS, and 4 in this group had a history of hypothyroidism. Main Outcome Measures: Levels of thyroid-stimulating hormone and free thyroxine. Results: There were 34 cases of hypothyroidism, a prevalence rate of 27%. The incidence of newly diagnosed cases was 9% (9 of 101). Six of the newly diagnosed cases were PS patients and three were NS patients. Eleven cases of undertreated hypothyroidism were found, in 9 PS patients and 2 NS patients. The rate of undertreated hypothyroidism in the PS population was 43% (9 of 21); in the nonsurgical population, it was 50% (2 of 4). The overall rate of undertreated hypothyroidism for both PS and NS groups was 44% (11 of 25). Conclusion: There is a high prevalence of hypothyroidism on an inpatient rehabilitation unit and a high rate of undertreated hypothyroidism in PS patients. Screening high-risk patients is recommended.