Trends in Reported AIDS Defining Illnesses (ADIs) among Participants in a Universal Antiretroviral Therapy Program: an Observational Study

Background: We examined trends in AIDS-defining illnesses (ADIs) among individuals receiving highly activeantiretroviral therapy (HAART) in British Columbia (BC), Canada to determine whether declines in ADIs could becontributing to previously observed improvements in life-expectancy among HAART patients in BC since 1996. Methods: HAART-naïve individuals aged ≥ 18 years who initiated treatment in BC each of the following timeperiods1996 - 1998; 1999 - 2001; 2002 - 2004; 2005 - 2007 were included. The proportion of participants withreported ADIs were examined for each time period and trends were analyzed using the Cochran-Armitage TrendTest. Cox proportional hazards models were used to examine factors associated with ADIs. Results: A total of 3721 individuals (81% male) initiated HAART during the study period. A total of 251 reports ofADIs were received from 214 unique patients. These occurred in a median of 4 months (IQR = 1-19 months) fromHAART initiation. The proportion of individuals with a reported ADI did not change significantly from 4.6% in theearliest time period to 5.8% in the latest period (p = 0.181 for test of trend). There were no significant declines inany specific ADI over the study period. Multivariable Cox models found that individuals initiating HAART during2002-04 were at an increased risk of ADIs (AHR = 1.55; 95% CI 1.04-2.32) in comparison to 1996 - 98, but therewere no significant differences in other time periods. Conclusions: Trends in reported ADIs among individuals receiving HAART since 1996 in BC do not appear toparallel improvements in life-expectancy over the same period