Comparing short-term mortality between people with and without HIV admitted to the intensive care unit: A single-centre matched cohort study (2000-2019).

Objectives: The survival rate of people with HIV admitted to intensive care units (ICUs) is approaching that of people without HIV. We conducted a matched-cohort study of people with and without HIV admitted to ICU at a large hospital to compare short-term mortality, during 2000-2019.

Methods: People with HIV were matched to people without HIV (1:2) on age, sex, admission year and Acute Physiology and Chronic Health Evaluation (APACHE)-II score. Applying logistic regression models fitted using independence estimating equations, we describe population-averaged associations of HIV with short-term (in-ICU, in-hospital) mortality during a patient's first admission to ICU, and explore whether these varied by year.

Results: A total of 177 people with HIV were matched to 354 people without HIV (71.2% vs. 71.2% male; median age: 47 vs. 48 years, median APACHE-II: 18 vs. 17, median admission year: 2013 vs. 2013). Among people with HIV, 73.4% were on antiretroviral therapy, 51.2% had HIV-RNA ≤50 copies/mL and median CD4 T-cell count was 132 cells/ $\mu$ L. People with HIV had higher in-ICU (24.3% vs. 15.3%) and in-hospital (31.6% vs. 20.1%) mortality. People with HIV had 1.69-fold higher odds (95% confidence interval: 1.03-2.76) of in-ICU mortality and 1.86 (1.19-2.91) higher odds of in-hospital mortality than people without HIV, adjusted for age, sex, year and APACHE-II. There was no evidence that these associations varied by year (p-interaction-in-ICU = 0.90; p-interaction-in-hospital = 0.46).

Conclusions: Our findings suggest that although outcomes have improved over time, people with HIV continue to have higher short-term in-ICU and in-hospital mortality following ICU admission compared with people without HIV with similar characteristics.