Identifying the Factors Influencing the Causes of Death in HIV/AIDS Patients Using Competing Risk Model

Background and

Mortality in HIV-positive patients is due to various reasons such as progression to AIDS or co-infection with AIDS and TB or other causes. In survival analysis, competing risk methods are used if there are different reasons for death. The purpose of this article was to identify the factors affecting various causes of death using competing risk methods.

This study was performed in 1231 HIV/AIDS patients attending Diseases Consulting Centers in Tehran between 2004 and 2013. The cause-specific hazard model was used to study the effect of factors on death due to co-infection with TB and AIDS and death by other causes. Data analysis was performed in R software and cmprsk package.

There were 181 patients who were co-infected with tuberculosis and AIDS. The median survival rate in AIDS-TB patients at the time of diagnosis was 6.51 ± 0.66 years and in those with AIDS alone was 11.56 ± 0.98 years. The effects of gender (12.94 [2.81-59.97]), CD4 (0.22 [0.08-0.54]), ART treatment (0.42 [0.24-0.75]), and isoniazid drug prophylaxis (0.08 [0.01-0.6]) were found to be significant on death due to co-infection with AIDS and TB. Also, the effects of sex (3.39 [2.03 -5.66]), CD4 (0.34 [0.22-0.51]), ART treatment (0.32 [0.23 - 0.45]), isoniazid drug prophylaxis (0.5 [0.29 - 0.85]), and Co-trimoxazole drug prophylaxis (0.34 [0.2-0.6]) were seen to be significant on death due to other reasons.

In this study, the cause-specific hazard model was applied to identify the risk factors for all causes of death. Therefore, this method could be used to identify the factors influencing causes of death (separately) and provide solutions to prevent the risks