Electronic Health Record Design Impacts Clinician Ordering Behavior: An Interrupted Time Series Analysis

Diagnostic stewardship is the science of improving diagnostic test use. Whether electronic health record (EHR) design influences clinician diagnostic testing behavior and electronic medical record interventions can improve diagnostic stewardship outcomes are key questions. We leveraged the natural experiment of a recent change in EHR platforms to investigate if changing how 2 commonly misused tests, blood cultures for acid-fast bacilli (AFB) and fungi, are displayed affected their use.

We performed a retrospective chart review of all AFB and fungal blood cultures at 4 hospitals with a shared EHR. The preintervention and postintervention periods were 52 and 26 weeks, respectively. The culture rate was standardized per 1000 patient-days and segmented into 2-week periods. Pre- and postintervention median rates were compared with the Wilcoxon rank sum test and further analyzed with an interrupted time series (ITS) analysis using a quasi-Poisson regression model.

The biweekly median AFB blood culture rate decreased by 41.6% in the postintervention period (0.46/1000 patient-days vs 0.79/1000 patient-days, P < 0.001). The median rate of fungal blood cultures decreased by 54.3% in the postintervention period (0.42/1000 patient-days vs 0.92/1000 patient-days, P < 0.001). In ITS analysis, the EHR change was associated with a level change in AFB (-31.8%, 95% CI: -54.6% to +2.6%) and fungal (-44.6%, 95% CI: -59.3% to -24.7%) blood culture use.

An electronic medical record design change resulted in decreased use of 2 commonly misused diagnostic tests. This highlights the impact of EHR design on clinician behavior and diagnostic stewardship programs' potential to reduce waste.