Background: Updating tetanus vaccinations for patients presenting to the emergency department with wounds is common, although often patients do not have good recollection of their prior immunization history. Tetanus updates are suggested if the prior vaccination was more than ten years ago, or for contaminated wounds if the prior update was more than five years ago. Patient’s immunization history may not be accurate in the Electronic Health Record (EHR), and when it is emergency providers may not be reviewing this data prior to ordering a tetanus booster. We studied the effect of a real-time electronic Clinical Decision Support (CDS) tool that warns providers upon ordering a tetanus vaccination update that the patient has a documented prior vaccination within the last ten years. The primary outcome was a reduction in unnecessary tetanus vaccinations in the emergency department.
Methods: This was a prospective quasi-experimental trial in three hospital EDs (two academic and one community). We studied adults where the ED provider ordered a tetanus booster vaccination. The study was conducted in two equal length phases between December 2016 and April 2017. The CDS alert was silent to ED providers in the initial baseline phase, and visible in the intervention phase. We compared the rate of administration of a tetanus booster vaccination during the ED encounter in each study phase. The alert displays guidance text on when tetanus boosters are indicated, and provides a link to Immunization report where the date of their most recent tetanus vaccination can be reviewed. The tetanus vaccination order can be removed directly from the alert.
Results: For the eligible population of 60,983 ED encounters, the rate of documented prior tetanus vaccination in the EHR within the last five and ten years was 22% and 35% respectively. Of the eligible population, 339 were included in the study population as they had a tetanus vaccination ordered with a prior documented history of vaccination within the last ten years. The median age was 51 years and 54% were female. During the baseline monitoring phase, a tetanus vaccination was administered 91% of the time the order was placed, compared to 55% in the intervention phase (OR = 0.12; 95% CI 0.07 to 0.22).
Conclusion: A simple CDS tool that warns users that a patient may have an up-to-date tetanus status reduces potentially unnecessary vaccinations.