Importance: Barriers to childhood vaccination against vaccine-preventable diseases, such as those due to human papillomavirus (HPV), are well known. However, the role of salience bias-the change in perception of risk due to increased familiarity with the outcome-in decisions to vaccinate children has not been explicitly studied.
Objective: To assess for salience bias in parental decisions to vaccinate children.
Design, setting, and participants: This retrospective cohort study used a time-to-event (survival) analysis to compare vaccination rates of children whose mothers had a history of cervical cancer or a cervical biopsy, who have experienced adverse vaccine-preventable outcomes, and for whom vaccination may be more salient, with a control group of children whose mothers had no such history. Participants were accrued from the MarketScan Commercial Database, including US children who turned 11 years old, when HPV vaccination is recommended, from January 1, 2014, to December 31, 2018. Data were analyzed from December 29, 2020, to September 17, 2021.
Exposures: Maternal history of cervical cancer or cervical biopsy.
Main outcomes and measures: Vaccination against HPV.
Results: A total of 757 428 children (370 878 girls [49.0%] and 386 550 boys [51.0%]) were identified, of whom 38 366 had mothers with a history of cervical biopsy alone and 1084 had mothers with a history of cervical cancer. Overall, 54.2% of children (55.7% of girls and 52.7% of boys) received at least 1 vaccination by 16 years of age. In a time-to-event analysis, HPV vaccination did not differ between children whose mothers had cervical cancer vs those whose mothers did not (hazard ratio [HR] for girls, 0.99 [95% CI, 0.86-1.13]; HR for boys, 1.08 [95% CI, 0.94-1.24]). Maternal history of cervical biopsy was associated with a minimally increased hazard of vaccination (HR for girls, 1.06 [95% CI, 1.04-1.09]; HR for boys, 1.04 [95% CI, 1.01-1.06]). There were no clinically meaningful differences between groups for the tetanus/diphtheria/acellular pertussis and meningococcal vaccinations, which are also recommended at 11 years of age.
Conclusions and relevance: In this analysis of salience bias in childhood vaccination decisions, mothers' personal history of cervical cancer or cervical biopsy was not associated with greater vaccination rates among children against HPV. These findings suggest that salience of vaccine-preventable outcomes may not have a major impact on childhood vaccine hesitancy in HPV; the role of salience should be investigated for other vaccines.