CD4 and infection: In many cases, the HRs essentially shifted when assumptions changed: e.g., the effect of CD4 being >200 cells/mm3 changed for HPV16/16-like infection from 1.68 to 1.86, and from 2.53 to 3.07 (still remaining significant) when 365 days were used in assumptions #2 and #3 instead of 450 days.