Diagnosis of thyroid disease in hospitalized patients - A systematic review

Background: The optimal approach for the diagnosis of hypothyroidism and hy perthyroidism in hospitalized patients is controversial. Objectives: To estimate the prevalence of undiagnosed thyroid disease among inpatients, review the usefulness of clinical signs and symptoms, and eluc idate the characteristics of the sensitive thyrotropin (thyroid-stimulating hormone) (sTSH) test in this population. Methods: We undertook a systematic review of the literature by conducting a MEDLINE search covering January 1966 through December 1996. Searching was conducted in duplicate and independently. Specific inclusion and exclusion criteria were predetermined. Results: Prevalence of thyroid disease among inpatients is approximately 1% to 2% and is similar to the outpatient population. Absence of clinical fea tures of thyroid disease lowers the pretest likelihood and makes screening even less useful. Presence of clinical features, especially those specific for thyroid disease (eg, goiter), may increase the pretest likelihood and i ncrease the yield of testing. Acute illness reduces the specificity of seco nd-generation sTSH tests for thyroid disease. The positive likelihood ratio associated with an abnormal sTSH test result in ill inpatients is about 10 compared with about 100 in outpatients. Conclusion: In unselected general medical, geriatric, or psychiatric inpati ent populations, sTSH testing provides a low yield of true-positive and man y false-positive results.