Table 1.

Sampling and testing methods for three subcohorts for which 3-year cumulative risks of CIN3+ and CIN2+ were estimated; HC2+ enrollment specimens were tested for HPV16, else HPV18, else 12 other high-risk types

Tested by cobasTested by MY09/MY11 PCR or cobas
Case–control statusTotal N in subcohortN% of TotalN% of Total
A. ASC-US Triage: Sample size of women with HC2+ ASC-US, ages 21 years and older (median 33), tested by cobas or MY09/MY11 PCR
Prevalent CIN2+1,30052840.6%1,17190.1%
Incident CIN2+62442668.3%45072.1%
B. Cotesting: sample size of women with HC2+/negative cytology, ages 30 years or older (median 40), tested by cobas or MY09/MY11 PCR
Prevalent CIN2+2042512.3%19495.1%
Incident CIN2+1,17689776.3%97082.5%
C. Primary HPV testing: sample size of women with HC2+, ages 25 years or older (median 38), tested by cobas or MY09/MY11 PCR
Prevalent CIN2+3,29076123.1%2,98990.9%
Incident CIN2+2,3151,68372.7%1,82778.9%

NOTE: A control was Hybrid Capture 2 (HC2) positive at enrollment but, during observation, never developed CIN2+. A prevalent case of CIN2+ (or CIN3+) was diagnosed after enrollment (HC2+) screening, prior to a second screen. An incident case of CIN2+ (or CIN3+) was HC2+ at enrollment, but diagnosed after at least the second screen. The table demonstrates that cobas data were supplemented by MY09/MY11 PCR data mainly for prevalent cases of CIN2+. Combining both testing methods, a high percentage of cases of CIN2+ were typed, permitting reasonably precise estimation of cumulative risk. A smaller fraction of HC2+ controls was tested.