AEGiS-14IAC: Trends in AIDS incidence and survival probabilities in the era of highly active antiretroviral therapy.

14th International AIDS Conference

Barcelona, Spain - July 7-12, 2002

Trends in AIDS incidence and survival probabilities in the era of highly active antiretroviral therapy.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. C10721)

Sasse A
Scientific Institute of Public Health, Brussels, Belgium

BACKGROUND: Surveillance of the HIV/AIDS epidemic in Belgium by means of cases reporting. Survival analysis based on mortality data collected through yearly follow up surveys. Material and

METHODS: The HIV surveillance in Belgium mainly uses two information sources: AIDS cases reporting by clinicians since 1984 and HIV cases reporting by AIDS Reference Laboratories since 1985. HIV and AIDS databases were linked in 1990. Data are validated for duplicate recording. In addition, a follow up survey is conducted each year to collect data on last consult and possible death of reported AIDS cases. Cox proportional hazards methods were used to estimate survival probabilities of AIDS patients diagnosed between 1994 and 1999.

RESULTS: The AIDS incidence in Belgium, adjusted for reporting delays, reached a plateau between 1991 and 1995 (range: 24.0-25.0 diagnosed cases/year/million). Compared to this '91-'95 plateau, the adjusted incidence decreased by 19% and 54% in 1996 and 1998 respectively. However, this trend was reversed in 2000: the adjusted incidence is estimated to increase by 50% in 2000 (15.5 cases/million) compared to 1999. The risk of death adjusted for age at AIDS diagnosis decreased significantly for patients diagnosed later than 1994. Compared with patients diagnosed in 1994, hazard ratios were of 0.55 (95%CI:0.43-0.71) for patients diagnosed in 1995, of 0.23 (95%CI:0.16-0.32) for patients diagnosed in 1996, of 0.15 (95%CI:0.09-0.25) for patients diagnosed in 1997, and of 0.13 (95%CI:0.07-0.23) for patients diagnosed in 1998. Trend was inverted in 1999: estimated hazard ratio of patients diagnosed in 1999 was of 3.04 (95%CI:1.30-7.06) relative to patients diagnosed in 1998.

CONCLUSIONS: The use of HAART has markedly reduced the AIDS incidence and mortality in the years 1996-1999. However, an increase in AIDS incidence and a decrease in survival probability were observed in the most recent period.

Keywords: AEGIS, Incidence, Antiretroviral Therapy, Highly Active, Acquired Immunodeficiency Syndrome, HIV Infections, Probability, HIV Seropositivity, AIDS Dementia Complex, Survival Analysis, Proportional Hazards Models, Risk Factors, Survival Rate, Belgium, Human, trends, epidemiology, mortality, organization & administration

020707
C10721