MOnitoring human papillomavirus Vaccine effect on Infection and cErvical diseases (MOVIE): Protocol for a cohort study using electronic health records from Yinzhou, China

Cervical cancer is the fourth most common cancer in women, with a high disease burden worldwide. Human papillomavirus (HPV) vaccination reduces HPV-related infection and associated cervical lesions and cancers. Few studies have explored HPV vaccination impact in real-world settings in China. This study aims to monitor HPV vaccine uptake and its effects on HPV-related diseases, evaluating vaccine effectiveness in a real-world context and complementing clinical trial results. Electronic health records (EHRs) from 2010 to 2020 from the Yinzhou Regional Health Information Platform (YRHIP) will be queried/extracted to identify and monitor HPV vaccine uptake in females aged 9-45 years, and HPV-related screening and prevalence (i.e., cervical HPV infection, cervical intraepithelial neoplasia [CIN] grades 1-3, and cervical cancer) in a cohort of females aged 9-70 years. Cervical cancer screening guidelines and expert consultation will be used for intra-database validation, to determine the best algorithm for identifying HPV-related disease. Pre-launch (2010-2016) and post-launch (2018-2020) periods are predefined. A time trend analysis will be performed to describe the vaccination impact on disease prevalence and, if prerequisite conditions are met, vaccine effectiveness will be computed using logistic regression, adjusting for age, calendar year, history of screening and HPV infection. Cohort study design, outcomes validation, data linkage, and multi-step statistical analyses could provide valuable experience for designing other real-world studies in the future. The study outcomes can help inform policy-makers about uptake and HPV vaccination policy in girls and women in Yinzhou District, and provide insights on progress toward achieving goals set by the World Health Organization.