Reducing 25-Hydroxyvitamin D Testing in a Large, Urban Safety Net System.

BACKGROUND: 25-Hydroxyvitamin D testing is increasing despite national guidelines and Choosing Wisely recommendations against routine screening. Overuse can lead to misdiagnosis and unnecessary downstream testing and treatment. Repeat testing within 3 months is a unique area of overuse. OBJECTIVE: To reduce 25-hydroxyvitamin D testing in a large safety net system comprising 11 hospitals and 70 ambulatory centers. DESIGN: This was a quality improvement initiative with a quasi-experimental interrupted time series design with segmented regression. PARTICIPANTS: All patients in the inpatient and outpatient settings with at least one order for 25-hydroxyvitamin D were included in the analysis. INTERVENTIONS: An electronic health record clinical decision support tool was designed for inpatient and outpatient orders and involved two components: a mandatory prompt requiring appropriate indications and a best practice advisory (BPA) focused on repeat testing within 3 months. MAIN MEASURES: The pre-intervention period (6/17/2020-6/13/2021) was compared to the post-intervention period (6/14/2021-8/28/2022) for total 25-hydroxyvitamin D testing, as well as 3-month repeat testing. Hospital and clinic variation in testing was assessed. Additionally, best practice advisory action rates were analyzed, separated by clinician type and specialty. KEY RESULTS: There were 44% and 46% reductions in inpatient and outpatient orders, respectively (p < 0.001). Inpatient and outpatient 3-month repeat testing decreased by 61% and 48%, respectively (p < 0.001). The best practice advisory true accept rate was 13%. CONCLUSION: This initiative successfully reduced 25-hydroxyvitamin D testing through the use of mandatory appropriate indications and a best practice advisory focusing on a unique area of overuse: the repeat testing within a 3-month interval. There was wide variation among hospitals and clinics and variation among clinician types and specialties regarding actions to the best practice advisory.