JMIR Publications

ABSTRACT

Background:

Human papillomavirus (HPV) vaccination is highly effective in preventing vaccine-type genital warts and cancers among men who have sex with men (MSM).

Objective:

The primary objective of this randomized controlled trial (RCT) was to evaluate the relative efficacies of two web-based and theory-based interventions with and without brief motivational interviewing (MI) over the phone in increasing HPV vaccination completion (receipt of three required doses) within a 24-month follow-up period, as compared to the control group.

Methods:

A three-arm parallel-group RCT was conducted between July 2017 and December 2019. Five telephone surveys were conducted at Baseline, Month 3, 6, 9 & 24 by blinded interviewers. Participants were Hong Kong Chinese speaking MSM aged 18-45 years having regular Internet access recruited from outreaching in venues, online recruitment and peer referral. Those who had ever received HPV vaccination were excluded. A total of 624 participants were randomized into either the Online Tutorial Only group (OT) (n=208), the Online Tutorial plus MI group (OT-MI) (n=208), or the control group (n=208); 459 (73.6%) completed follow-up evaluation at Month 24. Participants in the Group OT received a fully-automated online tutorial developed based on the Health Belief Model. On top of the same online tutorial, the Group OT-MI received brief MI over the phone. Reminders were sent to participants of the Group OT and Group OT-MI 1, 2, 4, 6 and 8 months afterwards. Participants in the control group received online health communication messages irrelevant to HPV or HPV vaccination. The research team validated self-reported HPV vaccination uptake. Intention-to-treat analysis was used for outcome analyses. Logistic regression models and multivariable linear regression models were used to test the between-group differences in primary and secondary outcomes. Baron and Kenny’s methods were used to test the mediation hypothesis.

Results:

Participants in the Group OT-MI reported significantly higher validated completion of HPV vaccination at Month 24 than the control group [17.3% (36/208) versus 7.2% (15/208), adjusted odds ratios (AOR): 1.57, 95%CI: 1.14, 2.17, p=.006]. However, the difference in HPV vaccination completion between the Group OT and the control group [11.5% (24/208) versus 7.2% (15/208), p=.17], or between the Group OT-MI and the Group OT (17.3% versus 11.5%, p=.13) was not statistically significant. The association between randomization status (Group OT-MI versus control) and HPV vaccination completion became statistically non-significant after controlled for changes in perceived susceptibility to HPV/HPV-related diseases (Month 24 versus baseline), whereas perceived susceptibility remained strongly associated with HPV vaccination uptake in the model (p<.001). The results suggested that change in perceived susceptibility fully mediated the intervention effect.

Conclusions:

The theory-based online tutorial with brief MI over the phone was effective in increasing HPV vaccination completion among Chinese MSM. Perceived susceptibility was an active theoretical component leading to behavioral changes. Clinical Trial: Clinicaltrials.gov NCT03286907