Parents' uptake of human papillomavirus vaccines for their children: a systematic review and meta-analysis of observational studies

Objective To examine factors associated with parents' uptake of human papillomavirus (HPV) vaccines for their children. Design Systematic review and meta-analysis. Data sources Cochrane Library, AIDSLINE, CINAHL, EMBASE, PsycINFO, Social Sciences Abstracts, Ovid MEDLINE, Scholars Portal, Social Sciences Citation Index and Dissertation Abstracts International from inception through November 2017. Methods We included studies that sampled parents and assessed uptake of HPV vaccines for their children (<= 18 years) and/or sociodemographics, knowledge, attitudes or other factors associated with uptake. Study risk of bias was assessed using the Effective Public Health Practice Project tool. We pooled data using random-effects meta-analysis and conducted moderation analyses to examine variance in uptake by sex of child and parent. Results Seventy-nine studies on 840 838 parents across 15 countries were included. The pooled proportion of parents' uptake of HPV vaccines for their children was 41.5% (range: 0.7%-92.8%), twofold higher for girls (46.5%) than for boys (20.3%). In the meta-analysis of 62 studies, physician recommendation (r=0.46 (95% CI 0.34 to 0.56)) had the greatest influence on parents' uptake, followed by HPV vaccine safety concerns (r=-0.31 (95% CI -0.41 to -0.16)), routine child preventive check-up, past 12 months (r=0.22 (95% CI 0.11 to 0.33)) and parents' belief in vaccines (r=0.19 (95% CI 0.08 to 0.29)). Health insurance-covered HPV vaccination (r=0.16 (95% CI 0.04 to 0.29)) and lower out-of-pocket cost (r=-0.15 (95% CI -0.22 to -0.07)) had significant effects on uptake. We found significant moderator effects for sex of child. Conclusions Findings indicate suboptimal levels of HPV vaccine uptake, twofold lower among boys, that may be improved by increasing physician recommendations, addressing parental safety concerns and promoting parents' positive beliefs about vaccines, in addition to expanding insurance coverage and reducing out-of-pocket costs. Limitations of this meta-analysis include the lack of intervention studies and high risk of bias in most studies reviewed. Further studies should disaggregate HPV vaccine uptake by sex of child and parent.