The clinical utility and cost-effectiveness of routine vitamin B12 screening in adult psychiatric patients.

Background: Diagnosing and treating vitamin B₁₂ deficiency in psychiatric populations is important, but the justification for routine screening in patients without risk factors or physical findings remains uncertain, especially in resource-limited settings.

Aim: This study aimed to assess the clinical utility and cost-effectiveness of routine vitamin B₁₂ screening in adult psychiatric inpatients.

Setting: The study was conducted at Townhill Hospital, a tertiary psychiatric facility in South Africa.

Methods: A retrospective chart review was performed for the period 01 July 2021 to 31 December 2022. Data collected included demographics, clinical diagnoses, medications, risk factors for deficiency, vitamin B₁₂ test results, associated costs, and clinical responses to abnormal findings.

Results: Of 366 patients (168 male, 198 female; mean age 35.95 ± 13.44 years), the mean serum vitamin B₁₂ level was 423.86 mmol/L (SD ± 233.37), with a median of 359 mmol/L. Vitamin B₁₂ deficiency was identified in eight patients (2.2%). The cost per deficient patient was R5780.73. Statistically significant associations were found between low B₁₂ levels and pregnancy, vegetarian diet, abdominal surgery, and metformin use (p < 0.05). Only half of the deficient patients received replacement therapy.

Conclusion: Routine vitamin B₁₂ screening in the absence of physical findings or known risk factors is not clinically or economically justified. Targeted screening should be considered to optimise resource use and patient outcomes.

Contribution: In resource-constrained environments, prioritising high-yield interventions is essential to improving care efficiency.