The clinical utility and cost effectiveness of routine thyroid screening in adult psychiatric patients presenting at Stikland Hospital, Cape Town, South Africa

Physical health examination in outpatients with schizophrenia: the cost effectiveness of laboratory screening tests

BACKGROUND

Guidelines on laboratory screening in schizophrenia recommend annual monitoring of fasting lipids and glucose. The utility and the cost effectiveness of more extensive laboratory screening have not been studied.

METHODS

The Living Conditions and the Physical Health of Outpatients with Schizophrenia Study provided a comprehensive health examination, including a laboratory test panel for 275 participants. We calculated the prevalence of the results outside the reference range for each laboratory test, and estimated the cost effectiveness to find an aberrant test result using the number needed to screen to find one abnormal result (NNSAR) and the direct cost spent to find one abnormal result (DCSAR, NNSAR x direct cost per test) formulas. In addition, we studied whether patients who were obese or used clozapine had more often abnormal results.

RESULTS

A half of the sample had 25-hydroxyvitamin D below, and almost one-fourth cholesterol, triglycerides or glucose above the reference range. One-fifth had sodium below and gamma glutamyltransferase above the reference range. NNSAR was highest for potassium (137) and lowest for 25-hydroxyvitamin D (2). DCSAR was below 5€ for glucose, all lipids and sodium, and below 10€ for creatinine and gamma glutamyltransferase. Potassium (130€), pH-adjusted ionized calcium (33 €) and thyroid stimulating hormone (33€) had highest DCSARs. Several abnormal results were more common in obese and clozapine using patients.

CONCLUSIONS

An annual laboratory screening panel for an outpatient with schizophrenia should include fasting glucose, lipids, sodium, creatinine, a liver function test and complete blood count, and preferably 25-hydroxyvitamin D.

Thyroid function testing in an inpatient mental health unit

OBJECTIVE

Thyroid function tests are a common screening investigation for patients admitted to a psychiatric inpatient unit.

METHOD

This study aimed to retrospectively assess the clinical utility of routine thyroid function testing performed on newly admitted psychiatric patients over a 4-year period in Victoria, Australia via chart review of all abnormal results identified.

RESULTS

Our retrospective audit revealed only two cases where identification of thyroid dysfunction informed patient management. In each case, the patient had a known history of thyroid disease. In this audit period, 893 patients required screening to yield one clinically relevant abnormal result, costing AU$24,975.57.

CONCLUSION

Such low clinical utility does not support routine admission thyroid function tests for psychiatric inpatients. We conclude that thyroid function tests should only be performed where the history and clinical signs suggest a likely contribution of thyroid dysfunction to the psychiatric presentation.