Background/Purpose

Herpes zoster infection causes serious morbidity and mortality in immunocompromised patients. Vaccination reduces the risk of zoster infection by up to 40% among patients with autoimmune disease and is recommended for patients aged 60 or above before starting immunosuppressive treatment. We implemented an electronic medical record based zoster vaccine decision support tool to improve vaccination rates among patients prescribed but not yet started on biologic medications.

Methods

We incorporated a zoster vaccine screening tool into the mandatory prior authorization (PA) process required for prescribing biologic Disease Modifying Anti-Rheumatic Drugs (DMARDs) across a multicenter rheumatology practice at a tertiary care academic medical center. The revised electronic PA form included a zoster section with decision support prompts to screen each patient’s appropriateness for the vaccine and to facilitate referral for the vaccine.

Process and outcome measures were analyzed during a 9 month period. The process measure assessed whether physicians accurately completed the zoster section of the PA form. The outcome measure assessed whether patients actually received the zoster vaccine. As a comparison group we used zoster immunization data derived from chart reviews of 123 patients over age 60 prescribed biologic medications in the same rheumatology unit during the 12 month period before implementation of the zoster screening decision support tool.

Results

During the 9 month period following the intervention, 119 PA forms with the zoster section were filled out for patients starting a biologic medication. The form was filled out correctly in 114/119 cases (Figure 1a). Prior to implementation of the zoster section on the PA form, 86/123 patients over age 60 who were prescribed a biologic were eligible for the vaccine without a contraindication. Of these 86 patients, 25% received the vaccine (Figure 1b). After the intervention, 41 of 119 patients prescribed a biologic were age-appropriate for the zoster vaccine, of whom 29 had one of the pre-defined contraindications to receiving the vaccine. Of the 12 age-eligible patients without contraindications, 42% received the vaccine (Figure 1c).

Conclusion

Incorporating a zoster immunization decision support tool in an electronic PA form for biologic medications was a successful method of prompting physicians to screen patients requiring biologic DMARD therapy for the zoster vaccine. After the support tool was implemented, a greater percentage of age-appropriate patients without a contraindication received the vaccine. Vaccination rates could be further improved by addressing a number of barriers including cost and logistical vaccine administration hurdles as well as by considering zoster screening prior to initiating a nonbiologic DMARD or prednisone.

Figure 1 Zoster Screening Tool – Process and Outcome Measures