Associated factors of HIV testing behaviours among sexual partners/spouses between young and middle-aged/older people living with HIV in China: a cross-sectional study.

Introduction: Understanding the factors influencing whether the sexual partners or spouses (SPS) of people living with HIV (PLWH) undergo HIV testing is critical for improving partner notification and testing strategies. Previous evidence has been inconsistent, often based on small samples, and insufficiently accounts for demographic heterogeneity. This study aimed to identify determinants of SPS testing and to examine whether these differ by age group. Methods: We conducted a cross-sectional study from January 2020 to December 2021 among 2554 newly diagnosed PLWH in Shenzhen, China. Demographic, clinical and behavioural data were collected, along with information on SPS HIV testing within 1 month of diagnosis. Participants were categorised into those with tested SPS (n=1451) and untested SPS (n=1103), and further stratified by age into younger (≤40 years, n=1264) and older (>40 years, n=1290) groups. Statistical analyses included χ Results: Among the 2554 PLWH, 1451 (56.81%) reported that their SPS had been tested. Increasing age of PLWH was negatively associated with SPS testing (OR=0.988, 95% CI 0.979 to 0.996, p=0.005). In the younger group, educational attainment was identified as a risk factor for their SPS being tested for HIV (OR=1.154, 95% CI 1.009 to 1.319, p=0.036). Conversely, for the older group, unemployment emerged as a risk factor for their SPS being tested for HIV (OR=1.876, 95% CI 1.410 to 2.497, p<0.01), while self-funded antiretroviral therapy (ART) was protective (OR=0.568, 95% CI 0.395 to 0.817, p=0.002). Across both age groups, female gender (OR1=2.230, 95% CI 1.512 to 3.290, P1<0.01; OR2=1.645, 95% CI 1.122 to 2.411, P2=0.011) and frequent condom use (OR1=1.112, 95% CI 1.001 to 1.235, P1=0.047; OR2=1.156, 95% CI 1.042 to 1.282, P2=0.006) were positively associated with SPS testing while homosexual transmission was negatively associated (OR1=0.409, 95% CI 0.313 to 0.535, P1<0.01; OR2=0.368, 95% CI 0.286 to 0.473, P2<0.01). Conclusions: Age modifies the factors influencing SPS HIV testing. Targeted interventions are needed, with emphasis on younger PLWH with limited education, older employed individuals and those self-funding ART. Strengthening disclosure support and tailoring interventions to age and socioeconomic context could improve SPS testing uptake and help reduce intrafamilial HIV transmission.