Title:
The study of human papillomavirus (HPV) vaccine uptake from a parental perspective: a systematic review of observational studies in the United States.

Abstract:
Despite widespread information about the human papillomavirus (HPV) vaccine, uptake continues to be low (CDC, 2010). HPV vaccine uptake may be maximized by better understanding factors likely to influence parents' decisions to vaccinate their age-recommended children. Previous reviews have summarized barriers and facilitators likely to influence parents' decision to vaccinate their adolescents (mostly daughters) against HPV; however, less attention has been given to summarize and evaluate the methodology. The aim of this study is to systematically review the methodology used in observational studies of HPV vaccine uptake from a parental perspective. A systematic search of Academic Search Premier, CINAHL, ERIC, Medline and PsycInfo to obtain relevant articles after FDA vaccine approval (2006 to present) yielded 446 studies, of which 17 studies were eligible. Results showed the majority of studies were cross-sectional, with random sampling from list-assisted sources being the most common method for data collection. Most studies used convenience samples and relied on parental self-report. Also, the majority of studies explored vaccine initiation, but only a few explored regimen completion and timely completion of vaccine regimen. Given that the effectiveness of the HPV vaccine is based on established recommendations for a three dose regimen within a timely interval, studies on factors likely to influence regimen completion and timely completion of regimen are essential to maximize the effectiveness and public health benefits of the vaccine. Research with more diverse samples, better and increased use of random sampling techniques, and the use of precise and objective measures of vaccine uptake to supplement parental self-report, is necessary to reduce selection and information biases in future studies. Studies to inform on factors likely to influence parents' decisions to vaccinate their sons against HPV are also needed.