[Impact of delayed diagnosis on the risk of all-cause mortality among sexually transmitted HIV infected patients: a cohort study based on CD4+T lymphocytes back-calculation method].

Objective: To explore the impact of delayed diagnosis on the risk of all-cause mortality among sexually transmitted HIV infected patients in Yuxi Prefecture, Yunnan Province. Methods: Baseline, treatment and follow-up data were downloaded from the National Comprehensive HIV/AIDS Prevention and Care Information System, between Jan 1, 2016 and Dec 31, 2023. The HIV infected time was back-calculated based on the regular decrease trend of CD4+T lymphocyte counts among antiretroviral therapy naïve patients, and the time interval between HIV infected and diagnosed was defined as the delayed diagnosis time. The restricted cubic spline functions were used to explore the linear and nonlinear relationships between delayed diagnosis time and all-cause mortality, and the Cox proportional hazards regression model was employed to analyze the association between delayed diagnosis time and all-cause mortality among sexually transmitted HIV infected patients. Results: Among 1, 832 HIV/AIDS cases, the median delayed diagnosis time was 4.27 (1.67, 7.18) years, and the median follow-up time was 3.83 (2.00, 5.92) years. there were 184 all-cause deaths were found during follow-up time, with a death density of 2.61 (95%CI: 2.24-2.98) per 100 person-years. Restricted cubic spline analysis showed a positive linear association between delayed diagnosis time and all-cause mortality risk (Poverall<0.001,Pnonlinearity=0.055). After adjusted for confounders, each 1-year delay in diagnosis was associated with a 26% increase in all-cause mortality risk (HR=1.26, 95%CI: 1.21-1.31). The all-cause mortality risk in the late-diagnosed group was 6.31 folds higher than that in the early-diagnosed group (HR=6.31, 95%CI: 3.92-10.14). There were no interaction between delayed diagnosed and age on all-cause mortality (Pinteraction=0.548), but the mortality density in the late diagnosed-age ≥50 years group (11.13/100 person-years) was much higher than that in the late diagnosed-age <50 years group (4.62/100 person-years). There were multiplicative and additive interactions were observed between delayed diagnosis and ART. The all-cause mortality risk in the late-diagnosis-naïve-ART group were 130.14 folds higher than that in the early/mid-diagnosis-ART group (HR=130.14, 95%CI: 79.24-213.75). The relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (SI) were 118.77 (95%CI: 55.81-181.73), 12.45 (95%CI: 6.92-22.38) and 0.91 (95%CI: 0.86-0.96), respectively. Conclusion: There were an interaction between delayed diagnosed and ART status on all-cause mortality among sexually transmitted HIV infected patients. we should focus on the patients late diagnosed, especially the those aged more than 50 years and those ART naïve, and taken efforts to prevent their high risk of death within one year after diagnosed.