Less is more: Two automated interventions to increase vitamin B₁₂ measurement when long-term proton pump inhibitor and decrease redundant testing

Introduction: To test the efficacy of two interventions to promote the measurement of serum vitamin B₁₂ (s- vitamin B₁₂) in patients with long-term proton pump inhibitor (PPI) use and to decrease inadequate s-vitamin B₁₂ measurement by implementing a minimum retest interval.

Material and methods: The Laboratory Information System (LIS) automatically registered s-vitamin B₁₂ when not ordered by General Practitioners to all requests patients with long term (>3years) PPI treatment, and with no s-vitamin B₁₂ testing in the previous year. Through the second intervention, the LIS reported the previous s-vitamin B₁₂ result through an explanatory comment in the report, when the test had been requested in the previous three months. We calculated the new diagnoses of vitamin deficiency (s-vitamin B₁₂ < 200 pg/mL), examined the number of tests needed to detect a new case and investigated the economic cost of each one identified by the intervention. Additionally, we counted the s-vitamin B₁₂ that were requested but not measured, and calculated the savings in reagent.

Results: The strategy added 548 s-vitamin B₁₂ and identified 47 new cases of vitamin B₁₂ deficit. The number of added s-vitamin B₁₂ needed to identify a new case by means of the intervention was 12. The total intervention reagent cost was 1446€, with a cost of 30.7€ per new case. The second intervention avoided unnecessary measurement of 611 tests, with 1613€ savings.

Conclusions: Through the two automated interventions we improved the diagnosis of vitamin B₁₂ deficiency, and decreased inadequate redundant s-vitamin B₁₂ measurement, cutting unnecessary laboratory costs.