Time to incidence of β-HPV infection in normal skin swabs and eyebrow hairs of men.

<p>Kaplan Meier estimate for time to incidence of any β HPV infection in a sample of 209 men. Participants who were negative for all HPV types at baseline were included. Time was counted until their first visit with a HPV positive sample or until censored. The 'last observation carried forward' approach was taken when counting time to incidence (e.g. 0 NA 1 pattern of HPV positivity at consecutive visits, the NA was treated as '0' and the time was counted in the time to incidence.). This only affected skin swab samples since most people were β globin or HPV positive for eyebrows and thus their samples were not removed.