The impact of a Facebook campaign among mothers on HPV vaccine uptake among their daughters: A randomized field study.

OBJECTIVE

The popularity of social networks provide an incredible opportunity to enhance the impact of preventive medicine programs. We aimed to assess whether a targeted Facebook campaign among mothers may increase the uptake of human Papilloma virus (HPV) immunization among their 8th-grade daughters.

METHODS

This field study was conducted among the members of a state-mandated health organization in Israel. Included were all 21,592 members who were mothers to 14 year-old daughters in the 2018-19 school-year. A total of 17,271 (80%) were randomly allocated to the campaign arm and the rest (n=4,321) were selected as a reference group. The Facebook ads addressed issues and concerns regarding HPV-related diseases and HPV vaccine. Main outcome measures were Facebook metrics on exposure to campaign and HPV immunization among eighth grade daughters of the study participants.

RESULTS

Between 8/2018-10/2018, Facebook ads were shown 1.8-million times (a reach of 88%). The uptake of HPV vaccine among daughters of women allocated to the campaign arm (55.3%) was similar (p = 0.749) to 55.0% in the control group. The only significant differences between study groups were observed when stratifying by SES level. In the lowest SES quartile, Facebook campaign significantly (p = .02) reduced vaccine uptake (35% vs. 39.0%), with a relative risk of 0.90 (95%CI: 0.82-0.98), while in the second SES quartile, Facebook campaign increased vaccine uptake from 52.6% to 55.8%, with a RR of 1.06 (95%CI,1.00-1.12). Among mothers in higher SES levels, daughters of exposed and unexposed mothers had similar immunization rates.

CONCLUSIONS

Facebook campaign may increase the uptake of HPV vaccine among daughters to mothers of medium-to-low SES level, but it may reduce vaccination among lower SES groups.