Cost-efficiency of laboratory testing among psychiatric inpatients

A set of tests to rule out medical conditions among psychiatric inpatients is still to be defined. A first step in this direction is to determine the utility of lab tests commonly used by psychiatrists.

Biochemical tests have been routinely performed on inpatients in a psychiatric hospitalization unit from 2006 to 2009. This study examines the prevalence of abnormal values in 1,278 laboratory tests performed on 894 patients. The number of subjects screened and the direct expenditure needed to find results outside the normal range were computed. Differences in clinical profiles were compared between diagnostic groups according to main diagnosis.

We found high rates of seropositive patients for human immunodeficiency virus (14.3%) and hepatitis B virus (15.7%). Most patients met at least one criteria of metabolic syndrome (67.6%). The detection of hepatic abnormalities was very efficient (65.71%), particularly for patients diagnosed with alcohol use disorders.

The cost-efficiency of lab tests in psychiatric units is greatly variable. Though results of this study may not be generalized due to the different prevalence of medical conditions, the methodology can be easily implemented across psychiatric services. Cost-effectiveness and costbenefit analyses are warranted.