RCT of Centralized Vaccine Reminder/Recall for Adults

A proven, but underutilized, method to increase current low vaccination rates is reminder/recall. Centralized reminder/recall using an Immunization Information System reduces the burden of an individual practice conducting reminder/recall. The objectives were to assess the effectiveness of centralized vaccine reminder/recall on improving adult vaccination rates using Colorado's Immunization Information System.

This study is a pragmatic RCT.

Denver Health patients were divided into three strata: 25,039 individuals aged 19-64 years without a high-risk condition for pneumococcal disease, 16,897 individuals aged 19-64 years with a high-risk condition, and 5,332 individuals aged ≥65 years. Data were collected from October 2015 to April 2016 and analyzed between September 2016 and June 2017.

Adults aged 19-64 years without a high-risk condition who needed influenza or tetanus, diphtheria, acellular pertussis vaccine or both, and adults with a high-risk condition and adults aged ≥65 years who needed influenza, or tetanus, diphtheria, acellular pertussis, or pneumococcal vaccine, or all three vaccines were randomized to receive up to three reminder/recalls or usual care.

Documentation of receipt of any needed vaccine in Immunization Information System ≤6 months after the reminder/recall was the primary outcome. A secondary outcome included implementation costs of the reminder/recall effort. A mixed effects model assessed the association between the intervention and receipt of any needed vaccine while controlling for gender, age, race, ethnicity, insurance type, and history of vaccine refusal.

The intervention was associated with receipt of any needed vaccine in the adults aged ≥65 years population (AOR=1.15, 95% CI=1.02, 1.30), but not the other two populations. Influenza vaccine was the source of this difference, with 32.0% receiving a vaccine in intervention versus 28.6% in usual-care groups (p≤0.01). Start-up and implementation costs per person were $0.86. In the population aged ≥65 years, 29.4 patients would need to be contacted to gain one additional vaccination.

Centralized reminder/recall was effective at increasing influenza vaccination rates in adults aged ≥65 years over a short time period, without burdening the practices, and at a reasonable cost.

This study is registered at www.clinicaltrials.gov NCT02133391.