Completion rates for the human papillomavirus vaccine (HPV) series among adolescents remain low. Effectiveness of recall with parents choosing the method (preference-based recall) for increasing HPV series completion is unstudied. Within a cluster-randomized trial, we examined effectiveness of preference-based recall compared with usual care for increasing series completion and the association of recall choices with completion.
All Kaiser Permanente Colorado pediatric practices (n = 7) were randomized to intervention (n = 4) or control (n = 3) by using covariate-constrained randomization. From January to June 2013, parents at intervention practices whose adolescents received HPV 1 were asked the recall method they preferred for subsequent doses and if they also wanted their child reminded. Completion rates were assessed 1 year after HPV 1.
At intervention practices, 374 (43%) of 867 patients were enrolled; 39% preferred text, 18% e-mail, 9% auto-dialer, and 34% 2-methods; 19% chose to have adolescent also recalled. Intervention adolescents were more likely to complete (63% vs 38%) than were controls (adjusted risk ratio 1.47 [1.38–1.57]) and less likely to be late in completing the series (45% vs 57%, P = .02). Rates of completion were similar between different recall methods, but significantly higher for those preferring e-mail and phone compared withother methods (90% vs 60%. P = .008). Completion rates were similar for adolescents who also received recalls (62%) versus those who did not (63%).
Preference-based recall was effective in increasing HPV series completion rates, with point estimates substantially higher than for most published studies of reminder/recall.