Development and validation of a mortality risk prediction index score for adults living with HIV and multiple chronic comorbidities.

Introduction: Aging while living with HIV poses new challenges in clinical management, mainly due to the onset of multiple chronic comorbidities. Population-specific risk prediction indices considering comorbidities and other risk factors are essential to comprehensively characterise disease burden among PLWH. We developed and validated a mortality risk prediction index (MRPi) to predict the risk of one-year all-cause mortality among people living with HIV (PLWH).

Methods: Participants were ≥18 years and had initiated antiretroviral therapy (ART) between 01/2001 and 12/2018, in British Columbia, Canada. The index date was randomly selected between one-year post-ART initiation and the end of the follow-up. Participants were followed for at least one year from the index date until 12/2019, the last contact date, or the date of death (all-cause), whichever came first. The MRPi included 18 physical/mental comorbidities, demographic and clinical variables, and ranged from 0 (no risk) to 100 (highest risk).

Results: The final model demonstrated the highest discrimination (c-statistic 0.8355, 95% CI: 0.8187-0.8523 in the training dataset and 0.7965, 95% CI: 0.7664-0.8266 in the test dataset). The comorbidities with the highest weights in the MRPi were substance use disorders, metastatic solid tumors and non-AIDs defining cancers. For example, for an MRPi of 30, the predicted one-year all-cause mortality was 0.2%, while an MRPi of 50 had a predicted mortality of 2.3%.

Conclusions: The MRPi provides a promising tool to assess the risk of short-term mortality among PLWH in the modern ART era that can inform clinical practice and health policy decisions.