Fig. 3

AIDS-incidence trends at presentation (a) and during the follow-up period (b) in HIV-transmission-route groups. a Overall, AIDS incidence at presentation declined from 28.8% in period 1 to a nadir of 10.5% in period 3 and then increased to 27.3% in period 5. After stratification by HIV-transmission route, however, AIDS incidence at presentation increased throughout the five cohort periods in the heterosexual (P for trend < 0.001), homosexual (P for trend < 0.001), and bisexual risk groups (P for trend = 0.648), whereas decreased to a nadir in period 3 and then increased to a peak in period 5 in in the PWID groups (P for trend < 0.001). b AIDS incidence during the follow-up period increased from 4.5% in period 1 to 11.9% in period 5. After stratification by HIV-transmission route, AIDS incidence during the follow-up period increased from period 1 to a peak in periods 3 and 4 and then declined in period 5 in heterosexual (P for trend < 0.001), homosexual (P for trend < 0.001), and bisexual risk groups (P for trend = 0.549), whereas in PWIDs it increased throughout the five cohort periods (P for trend < 0.001)