Impact of donor CMV status on antiviral use. (A) The number of days that each D⁺/R⁺ or D⁻/R⁺ recipient received antiviral drug therapy (GCV or foscarnet). The box plot overlays show the median and the central 50% of the data. The median is zero for the D⁺/R⁺ group, as the majority did not require antivirals. P value determined by rank-sum test. (B) The cumulative incidence of antiviral use, estimated by the method of Kalbfleisch and Prentice,⁴⁰  incorporates recurrent events. Most events occur between 30 to 90 days posttransplant, but the separation of the curves continues to increase, as late events occur more frequently in the D⁻ group. The excess risk in the D⁻ group was statistically significant, adjusted for pre-HCT covariates (P < .001) and for GVHD (P = .009, Table 3). DPT, days posttransplant.