Centralized Reminder/Recall to Increase Influenza Vaccination Rates: A Two-State Pragmatic Randomized Trial

Centralized reminder/recall (C-R/R) by health departments using immunization information systems is more effective and cost effective than practice-based approaches for increasing childhood vaccines but has not been studied for influenza vaccination. We assessed effectiveness and cost of C-R/R for increasing childhood influenza vaccination compared with usual care.

Within Colorado (CO) and New York (NY), random samples of primary care practices (pediatric, family medicine, and health center) were selected proportionate to where children are served-65 practices (N = 54,353 children) in CO; 101 practices (N = 65,777) in NY. We conducted 4-arm RCTs per state (1, 2, or 3 autodial reminders vs usual care), with randomization at the patient level within practices from 10/2016 to 1/2017.

In CO, the maximum absolute difference in receipt of ≥1 influenza vaccine was 1.7% between the 2 R/R group and control (adjusted risk ratio [ARR] of 1.06 [1.01, 1.10]); other R/R arms did not differ significantly. In NY, ARRs for the study arms versus control varied from 1.05 (1.01, 1.10) for 3 R/R to 1.06 (1.01, 1.11) for 1-2 R/R groups and maximum absolute increase in vaccination was 0.6%. In time-to-event analyses, study arm was a significant predictor of vaccination in CO (P = .001) but not in NY. Costs/child randomized to one message were $.17 in CO and $.23 in NY.

C-R/R for influenza vaccine using autodial had low-level effects on increasing influenza rates in 2 states. Given the feasibility and low cost of C-R/R in previous trials, its utility for influenza should be re-examined using different modalities.