Abstract
PURPOSE: Centralized reminder/recall (C-R/R) using Immunization Information Systems has been effective in increasing childhood immunization rates. Previously, C-R/R using autodialer for human papillomavirus (HPV) vaccine did not raise rates. We assessed C-R/R for HPV vaccine using other modalities and focused on younger adolescents. METHODS: We conducted a three-arm pragmatic RCT in randomly sampled primary care practices in Colorado (n = 88) and New York (n = 136), proportionate to where adolescents received care. We randomized, within practices, adolescents aged 11-14 years who had not completed the HPV vaccination series to receive C-R/R using different modalities (Colorado: autodialer, mail, or control; New York: autodialer, text, or control). Up to two reminders were sent in intervention arms for each dose needed between 2/2017 and 12/2018. RESULTS: In Colorado, no significant differences were found for series initiation (31.3% control, 31.1% autodial, 31.8% mail), with slight improvement for series completion in the autodialer arm (29.7% control, 31.1% autodialer, p = .04) but not the mail arm (30.9%, p = .06). No significant differences were found in New York for series initiation (24.1% for all arms) or completion (17.1% control, 16.9% autodial, 17.9% text). Adjusted analyses showed higher completion rates for the autodialer arm in Colorado but not for other arms. In Colorado, C-R/R reduced time to series completion by around 2 months. Cost per adolescent was $1.81 for mail; under $.40 for all other modalities. CONCLUSIONS: C-R/R has less benefit for raising HPV vaccination rates than other studies have noted for childhood immunizations, although it may quicken series completion at little cost.