(O-G2) Laboratory Testing Is Indicated for Older but Not Younger Emergency Department Psychiatric Patients

Objectives: To assess the value of laboratory testing for emergency department psychiatric patients of different ages by examining the fraction of those patients admitted medically instead of psychiatrically.

Background: Previous studies have shown that routine laboratory testing has low yield for identifying unsuspected medical conditions for most emergency department (ED) patients who present for psychiatric problems. About 20% of ED psychiatric patients are over 65 years old and these patients are more likely to have chronic medical conditions than younger patients. These conditions may worsen during exacerbations of psychiatric illnesses and, in fact, may contribute to these exacerbations. We hypothesize that a larger proportion of elderly than younger patients presenting for psychiatric problems require medical admission, and that the reasons for such admission are exacerbations of chronic medical conditions.

Methods:

Design: Retrospective cohort. Population: Consecutive ED patients presenting with psychiatric conditions in the years 2019-2021. Setting: Suburban ED with an annual ED volume of 90,000 patients, an ED residency, and a separate area for psychiatric patients. This area has specialized psychiatric personnel, including psychiatric social workers and psychiatrists. ED healthcare providers initially evaluate the patients and then request psychiatric consultation. Protocol: A database of ED psychiatric patients is maintained by the hospital. We tallied the number of psychiatric visits and the number of these patients admitted for medical conditions. We calculated and plotted the percent admitted medically by decade of life. We also tallied admissions for specific conditions, namely drug-related diagnoses (including alcohol abuse) and dementia.

Results: The database contained 8018 patients. The median age was 30 years (interquartile range: 19-51); 51% were female. Of these, 175 (2.2%) were admitted for medical conditions. The percent admitted medically varied markedly by decade of life, ranging from an average of < 1% in the first four decades of life to 15% in the tenth decade (See Figure). Drug-related diagnoses were found in patients admitted medically in the 3rd through 8th decades of life, and accounted for 46% of the medical admissions in the 4th-6th decades of life. Of medical admissions in the 8-10th decades of life, 30% were for dementia.

Conclusions: We found a higher admission rate for medical conditions in elderly than younger psychiatric ED patients. The most frequent chronic medical condition in elderly patients that was identified as the reason for medical admission was dementia. Our results confirm that the routine requirement for laboratory testing in younger psychiatric ED patients is unlikely to be useful.

References (Optional):

Funding (Optional): None.