A Joint Model of Persistent Human Papillomavirus Infection and Cervical Cancer Risk: Implications for Cervical Cancer Screening

• Activity Number: 34
• Type: Contributed
• Date/Time: Sunday, August 3, 2014 : 2:00 PM to 3:50 PM
• Sponsor: Health Policy Statistics Section
• Author(s): Li Cheung*+ and Hormuzd Katki and Barbara Fetterman and Philip Castle and Rajeshwari Sundaram
• Companies: George Washington University and National Cancer Institute and Kaiser Permanente and Albert Einstein College of Medicine and Eunice Kennedy Shriver National Institute of Child Health and Human Development
• Keywords: HPV ; cancer screening ; risk modeling ; joint modeling of longitudinal and survival data ; medical guidelines

Abstract

New cervical cancer screening guidelines recommend women get tested for human papillomavirus(HPV). To inform decisions about screening intervals, we calculate the increase in precancer risk per year of continued HPV infection. However, both time to onset of precancer and time to HPV clearance are interval-censored, and onset of precancer informatively censors HPV clearance. We develop a novel joint model for time to clearance of HPV and time to precancer using shared random effects, where estimated mean duration of each woman's HPV infection is a covariate in the submodel for time to precancer. We analyze data on 9,553 HPV-positive/Pap-negative women. After 2 years, marginal population-average precancer risk was 5%, suggesting a 2-year interval to control population-average risk at 5%. In contrast, our joint model reveals that almost all women exceeding 5% individual risk in 2 years also exceeded 5% in 1 year, suggesting a 1-year interval is better to control individual risk at 5%. The example suggests that risk models capable of predicting individual risk may have different implications than population-average risk models currently used for informing medical guideline development.