Fig. 1.

Study population in KPNC's Persistence and Progression (PaP) study.

¹Cervical testing visits obtained between January 1, 2007- January 31, 2011 ² PaP: Persistence and Progression study ³ KPNC: Kaiser Permanente North California ⁴ HC2: Hybrid Capture 2 ⁵ HPV typing was done with Linear Array (6910), cobas (6281), MY09/11 (3422), and Onclarity (9953) ⁶. HR: high risk types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68) ⁷. Non-oncogenic HPV infections exclude HPV66 ⁸. This first collection was defined as “baseline”. Specimens collected after baseline were referred to as “follow-up”. Only samples with HC2+ results at baseline were used, with no additional follow-up specimens or correction for potential infections missed by HC2.