Cause-specific life expectancies after 35 years of age for human immunodeficiency syndrome-infected and human immunodeficiency syndrome-negative individuals followed simultaneously in long-term cohort studies, 1984-2008

Abstract

Parametric and semiparametric competing risks methods were used to estimate proportions, timing, and predictors of acquired immune deficiency syndrome (AIDS)-related and non-AIDS-related mortality among individuals both positive and negative for the human immunodeficiency syndrome (HIV) in the Multicenter AIDS Cohort Study (MACS) and Women's Interagency HIV Study (WIHS) from 1984 to 2008 and 1996 to 2008, respectively. Among HIV-positive MACS participants, the proportion of deaths unrelated to AIDS increased from 6% before the introduction of highly active antiretroviral therapy (HAART) (before 1996) to 53% in the HAART era (P < 0.01); the median age of persons who died from non-AIDS-related causes after age 35 years increased from 49.0 to 66.0 years (P < 0.01). In both cohorts during the HAART era, median ages at time of non-AIDS-related death were younger for HIV-positive individuals than for comparable HIV-negative individuals (8.7 years younger in MACS (P < 0.01) and 7.6 years younger in WIHS (P < 0.01)). In a multivariate proportional cause-specific hazards model, unemployment (for non-AIDS death, hazard ratio (HR) = 1.8; for AIDS death, HR = 2.3), depression (for non-AIDS death, HR = 1.4; for AIDS death, HR = 1.4), and hepatitis B or C infection (for non-AIDS death, HR = 1.8, for AIDS death; HR = 1.4) were significantly (P < 0.05) associated with higher hazards of both non-AIDS and AIDS mortality among HIV-positive individuals in the HAART era, independent of study cohort. The results illuminate the changing face of mortality among the growing population infected with HIV.

Figure 1.

Estimated probability density functions for cause-specific mortality after 35 years of age by highly active antiretroviral therapy era in the Multicenter AIDS Cohort Study, 1984–2008. Vertical hash marks and text labels indicate estimated median ages at death. Percentages in legend indicate the final estimated proportion of all-cause mortality along with the estimated location and scale parameters from Weibull models.

Figure 2.

Estimated probability density functions for cause-specific mortality after 35 years of age in the highly active antiretroviral therapy era (1996–2008), Multicenter AIDS Cohort Study and Women's Interagency HIV Study. Vertical hash marks and text labels indicate estimated median ages at death. Percentages in legend indicate the final estimated proportion of all-cause mortality along with the estimated location and scale parameters from Weibull models.