Endocrine Abstracts

Thyroid dysfunction is common and the clinical presentation of subjects with abnormal thyroid hormone concentrations varies widely. Whilst acute illness may affect the interpretation of thyroid function tests, delaying diagnosis and treatment of thyroid dysfunction may have significant consequences. We set out to determine the likelihood of thyroid function testing and the factors influencing the probability of serum TSH measurement in hospitalised patients with a recorded diagnosis of thyroid dysfunction. Out of 280 000 admissions between January 2007 and December 2011 to our centre we identified 9912 admissions with a diagnosis of hypothyroidism (91.6%) or hyperthyroidism (8.4%) at discharge. 78.3% were female and the mean age was 66.1±0.7 years. 67.5% were admitted as emergency and mean length of stay was 8.5±0.13 days. The main reason for admission was coded according to the ICD10 classification. The primary reason for admission was circulatory diseases in 22.4%, digestive disorders in 14.5%, neoplasms in 13.6% and respiratory conditions in 7.8%. Serum TSH concentrations were measured in 1852 (18.6%). Longer hospital stay (2–4 days: AOR=2.11 (1.74–2.57), P<0.001; 5–10 days: AOR=3.56 (2.95–4.30), P<0.001; >10 days: AOR=10.33 (8.65–21.36), P<0.001 vs 1 day) and emergency admission (AOR=2.62 (2.25–3.06), P<0.001 vs elective admission) were associated with increased probability of testing. Diagnosis of hyperthyroidism (AOR=2.53 (2.11–3.03), P<0.001 vs hypothyroidism) and older age (AOR=1.01 (1.00–1.01) per annual increment, P=0.05) had higher likelihood of serum TSH measurement. Primary diagnoses of neoplasms (AOR=0.56 (0.45–0.70), P<0.001) or digestive disorders (AOR=0.67 (0.55–0.81), P<0.001) were associated with reduced odds of thyroid function testing compared with circulatory diseases.

Conclusions: Only one in five subjects with a recorded diagnosis of thyroid dysfunction underwent thyroid function testing. Admission for circulatory causes and emergency reasons were associated with an increased likelihood of testing. A diagnosis of hyperthyroidism, older age and longer hospital stay were independent factors predicting increased probability of serum TSH measurement. Further analysis may identify patient groups who may benefit from thyroid function testing during hospitalisation.