Randomized controlled trial of centralized vaccine reminder/recall to improve adult vaccination rates in an accountable care organization setting.

Our objectives were to assess 1) effectiveness of using Colorado's Immunization Information System (CIIS) to send out vaccine reminder/recalls (R/Rs) centrally vs. usual care for adult vaccine delivery within an accountable care organization (ACO) and 2) practice staff's perception of centralized R/R. From 9/2016 to 4/2017, we conducted a randomized controlled trial among adults enrolled in a Medicaid ACO at six healthcare entities. Adults were divided into two strata: 15,153 age 19-64 and 616 age 65+. Adults age 19-64 who needed influenza and/or Tdap vaccine, and adults age 65+ who needed influenza, and/or Tdap, and/or a pneumococcal vaccine were randomized to receive up to 3 R/Rs by autodialed telephone and mail or usual care. Documentation of receipt of any needed vaccines in CIIS within six months was the primary outcome. We assessed intervention effectiveness using mixed effect logistic regression. Thirteen semi-structured exit interviews were conducted with staff from each healthcare entity. The intervention was not associated with the primary outcome for the age 19-64 population [OR 1.06 (95% CI 0.98-1.15)] or age 65+ population [(OR 0.96 (0.69-1.32)]. Practice staff perceived the intervention to be beneficial and not burdensome. Perceived barriers included lack of availability of appointments and adults receiving only influenza vaccine when other vaccines were needed. In conclusion, centralized R/R was not effective at improving adult vaccination rates in a Medicaid ACO. Future studies should consider better harmonizing vaccine centralized R/Rs with vaccine delivery efforts within the practice setting. Clinical Trials Registration Number: NCT02133391.