Effectiveness of centralized text message reminders on human papillomavirus immunization coverage for publicly insured adolescents

Purpose: We evaluated a managed care organization (MCO)-generated text message reminder-recall system designed to improve human papillomavirus (HPV) vaccination coverage.

Methods: We conducted a randomized controlled trial of text reminder-recall for parents of 3,812 publicly insured adolescents aged 11-16 years with no prior HPV vaccinations who were enrolled in a single MCO and were patients at one of 39 primary care practices. We determined the rate of HPV receipt for intervention versus control with the Kaplan-Meier failure function and determined hazard ratios using a clustered stratified Cox model, clustering on primary care provider and stratified on practice. We examined results for all subjects, and for those with a valid phone number, stratified by age group (11-13 years and 14-16 years) and gender. A post hoc analysis included all subjects and controlled for age and gender.

Results: HPV dose 1 vaccination rates were not significantly different when all participants were included, but for the subset of parents (54%) able to receive messages, HPV dose 1 rates were 13% for the control group and 16% for the intervention group; hazard ratio, 1.3 (95% confidence interval, 1.0-1.6; p = .04), when controlling for age and gender. There were no significant findings in the analysis stratified by age and gender.

Conclusions: MCO-based text reminders are feasible and have a modest effect on HPV dose 1 vaccination rates for those parents able to receive text messages with valid phone numbers in the MCO database. Future studies should examine a similar intervention for those parents who already accepted the first HPV vaccine dose.