A feasibility trial of parent HPV vaccine reminders and phone-based motivational interviewing.

Background: We assessed the feasibility and acceptability of a sequential approach of parent-targeted HPV vaccine reminders and phone-based Motivation Interviewing (MI).

Methods: In 2016, we selected all 11- to 12-year-old boys and girls seen in one clinic whose vaccine records did not include the HPV vaccine (n=286). By gender, we individually randomized parents of adolescents to an interactive text message (74 girls and 45 boys), postcard reminder (46 boys and no girls because of previously demonstrated efficacy), or standard care group (75 girls and 46 boys). Reminders were sent with medical director permission and a HIPAA waiver. Two months after reminders, among the adolescents whose vaccine records still did not include the HPV vaccine, we selected a gender-stratified random sample of 20 parents for phone-based MI. We assessed the percentage of deliverable messages, the percentage of parents' responding to the interactive text message, parent acceptability of receiving a text message, and MI parent responsiveness and interviewer competence (MI Treatment Integrity Coding system).

Results: Nearly all messages were deliverable (98% of postcards and 74% of text messages). Six of the 88 parents (7%) receiving text messages scheduled an appointment through our interactive system. The acceptability survey response rate was 37% (38/102). Respondents were favorable toward vaccine reminders for all parents (82%). Among 20 sampled parents, 17 were reached by phone of whom 7 completed MI, 4 had or were getting the HPV vaccine for their child, and 5 expressed disinterest. Across the 7 MI calls, the interviewer was rated 100% MI adherent and scored an average 4.19 rating for Global Spirit.

Conclusion: Without providing explicit consent to receive vaccine-related messages, parents nonetheless found postcards and interactive text messages acceptable. Centralizing MI to phone calls with trained staff was acceptable to parents and resulted in highly MI-adherent interviews.