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 active antiretroviral therapy (HAART) in British Columbia (BC), Canada to determine whether declines in ADIs could be contributing 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 time-periods 1996 - 1998; 1999 - 2001; 2002 - 2004; 2005 - 2007 were included. The proportion of participants with reported ADIs were examined for each time period and trends were analyzed using the Cochran-Armitage Trend Test. 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 of ADIs were received from 214 unique patients. These occurred in a median of 4 months (IQR = 1-19 months) from HAART initiation. The proportion of individuals with a reported ADI did not change significantly from 4.6% in the earliest time period to 5.8% in the latest period (p = 0.181 for test of trend). There were no significant declines in any specific ADI over the study period. Multivariable Cox models found that individuals initiating HAART during 2002-04 were at an increased risk of ADIs (AHR = 1.55; 95% CI 1.04-2.32) in comparison to 1996 - 98, but there were no significant differences in other time periods. CONCLUSIONS: Trends in reported ADIs among individuals receiving HAART since 1996 in BC do not appear to parallel improvements in life-expectancy over the same period.