Although autodialer centralized reminder and recall (C-R/R) from state immunization information systems (IISs) has been shown to raise childhood vaccination rates, its impact on human papillomavirus (HPV) vaccination rates is unclear. In a 4-arm pragmatic randomized controlled trial across 2 states, we randomly selected practices representative of the specialty (pediatrics, family medicine, and health center) where children received care. Within each practice, patients 11 to 17.9 years old who had not completed their HPV vaccine series (NY: N = 30 616 in 123 practices; CO: N = 31 502 in 80 practices) were randomly assigned to receive 0, 1, 2, or 3 IIS C-R/R autodialer messages per vaccine dose. We assessed HPV vaccine receipt via the IIS, calculated intervention costs, and compared HPV vaccine series initiation and completion rates across study arms. In New York, HPV vaccine initiation rates ranged from 37.0% to 37.4%, and completion rates were between 29.1% and 30.1%, with no significant differences across study arms. In Colorado, HPV vaccine initiation rates ranged from 31.2% to 33.5% and were slightly higher for 1 reminder compared with none, but vaccine completion rates, ranging from 27.0% to 27.8%, were similar. On adjusted analyses in Colorado, vaccine initiation rates were slightly higher for 1 and 3 C-R/R messages (adjusted risk ratios 1.07 and 1.04, respectively); completion rates were slightly higher for 1 and 3 C-R/R messages (adjusted risk ratios 1.02 and 1.03, respectively). IIS-based C-R/R for HPV vaccination did not improve HPV vaccination rates in New York and increased vaccination rates slightly in Colorado.

Objective

To evaluate the effect of different modalities of centralized reminder/recall (autodialer, text, mailed reminders) on increasing childhood influenza vaccination.

Study design

Two simultaneous randomized clinical trials conducted from October 2017 to April 1, 2018, in New York State and Colorado. There were 61 931 children in New York (136 practices) and 23 845 children in Colorado (42 practices) who were randomized to different centralized reminder/recall modalities-4 arms in New York (autodialer, text, mailed, and no reminder control) and 3 arms in Colorado (autodialer, mailed, and no reminder control). The message content was similar across modalities. Up to 3 reminders were sent for intervention arms. The main outcome measure was receipt of ≥1 influenza vaccine.

Results

In New York, compared with the control arm (26.6%), postintervention influenza vaccination rates in the autodialer arm (28.0%) were 1.4 percentage points higher (adjusted risk ratio, 1.06; 95% CI, 1.02-1.10), but the rates for text (27.6%) and mail (26.8%) arms were not different from controls. In Colorado, compared with the control arm (29.9%), postintervention influenza vaccination rates for the autodialer (32.9%) and mail (31.5%) arms were 3.0 percentage points (adjusted risk ratio, 1.08; 95% CI, 1.03-1.12) and 1.6 percentage points (adjusted risk ratio, 1.06; 95% CI, 1.02-1.10) higher, respectively. Compared with the control arm, the incremental cost per additional vaccine delivered was $20 (New York) and $16 (Colorado) for autodialer messages.

Conclusions

Centralized reminder/recall for childhood influenza vaccine was most effective via autodialer, less effective via mail, and not effective via text messages. The impact of each modality was modest. Compared with no reminders, the incremental cost per additional vaccine delivered was also modest for autodialer messages.

Trial registration

ClinicalTrials.gov: NCT03294473 and NCT03246100.