The Characteristics and Risk Factors of Web-Based Sexual Behaviors Among Men Who Have Sex With Men in Eastern China: Cross-sectional Study

Characteristics of and Factors Associated With Partner Service Uptake Cascade Among People With Newly Reported HIV/AIDS Diagnoses in Southeastern China in 2022: Cross-Sectional Survey

BACKGROUND

HIV notification and testing integrated into partner service (PS) practices among HIV-positive individuals have been proven to be an efficient approach for case finding, although it remains a weak link in China. Although nonmarital sexual activities accounted for a large proportion of newly diagnosed HIV-positive cases in China, little is known about PS uptake and associated factors within nonmarital partnerships.

OBJECTIVE

This study aimed to describe HIV PS utilization and its associated factors among HIV-positive individuals with nonmarital sexual partners.

METHODS

We recruited newly diagnosed HIV-positive individuals who had nonmarital sexual partners in 2022 in Zhejiang Province and offered them PS. We described the PS uptake cascade within sexual partner categories and analyzed the associated factors with 3 primary outcomes from the participants' perspective: nonmarital partner enumeration, HIV testing, and HIV positivity.

RESULTS

In this study, 3509 HIV-positive individuals were recruited as participants, and they enumerated 2507 nonmarital sex partners (2507/14,556, 17.2% of all nonmarital sex partners) with contact information. Among these, 43.1% (1090/2507) underwent an HIV test, with an HIV-positive rate of 28.3% (309/1090). Heterosexual commercial partners were the least likely of being enumerated (441/4292, 10.3%) and had the highest HIV-positive rate (40/107, 37.4%). At the participant level, 48.1% (1688/3509) of the participants enumerated at least one nonmarital sex partner with contact information, 52.7% (890/1688) had a sex partner tested for HIV, and 31% (276/890) had at least one nonmarital sex partner who tested positive. Multivariate analysis indicated that gender and transmission route were associated with both nonmarital sex partner enumeration and HIV testing. Age and occupation were associated with nonmarital sex partner enumeration and HIV positivity. Compared with participants who had no regular nonmarital sex partner, those who had a regular nonmarital sex partner were more likely to enumerate nonmarital sex partners (adjusted odds ratio [aOR] 3.017, 95% CI 2.560-3.554), have them get tested for HIV (aOR 1.725, 95% CI 1.403-2.122), and have an HIV-positive nonmarital sex partner (aOR 1.962, 95% CI 1.454-2.647).

CONCLUSIONS

The percentage of partner enumeration was low, and HIV testing rate was moderate among nonmarital partnerships of HIV-positive individuals. More efforts should be made to improve PS practices among HIV-positive individuals and address the gap in partner enumeration, especially for heterosexual commercial nonmarital partnerships. Additionally, enhancing PS operational skills among health care personnel could increase the overall efficiency of PS uptake in China.

Understanding Motivations for Dating App Use Among Gay and Bisexual Men: Validation, Latent Profile Analysis, and Differences in Health Outcomes

While there has been a proliferation in gay dating app (GDA) use in China, research into their potential effects on health outcomes, particularly mental health outcomes, among gay and bisexual men is lacking. The motivations for GDA use are diverse, and understanding users' motivation profiles may provide a necessary starting point for exploring the heterogeneous effects of GDA use on health outcomes. A cross-sectional survey of the motivations for GDA use and other health outcome variables (i.e., condom use frequency, self-stigma, and subjective emptiness) was conducted among 366 Chinese gay and bisexual men. The results of exploration structure equation modeling indicate that the GDA Use Motivation Scale, with a four-factor first-order model, had strong psychometric properties. Then, latent profile analysis (LPA) based on the mean scores of four aspects of motivation was performed. The results of the LPA revealed the existence of four profiles: "Weak motivations" (30.9%), "Differentiated motivations" (17.8%), "Moderate motivations" (30.3%), and "Strong motivations" (21.0%). Differences in health outcomes among the motivation profiles were found by using the Bolck-Croon-Hagenaars approach. Overall, most participants (60.1%) tended to use condoms consistently, regardless of how strong their GDA use motivation was; however, stronger GDA use motivations were associated with higher levels of self-stigma and subjective emptiness. We call for more research to focus on the real needs behind and motivations for GDA use so that all such app users' voices can be heard, as well as to raise awareness about the potential health risks associated with GDA use among Chinese gay and bisexual men.

Latent Heterogeneity of Online Sexual Experiences and Associations With Sexual Risk Behaviors and Behavioral Health Outcomes in Chinese Young Adults: Cross-Sectional Study

BACKGROUND

Online sexual experiences (OSEs) are becoming increasingly common in young adults, but existing papers have reported only on specific types of OSEs and have not shown the heterogeneous nature of the repertoire of OSEs. The use patterns of OSEs remain unclear, and the relationships of OSEs with sexual risk behaviors and behavioral health outcomes have not been evaluated.

OBJECTIVE

This study aimed to examine the latent heterogeneity of OSEs in young adults and the associations with sexual risk behaviors and behavioral health outcomes.

METHODS

The 2021 Youth Sexuality Study of the Hong Kong Family Planning Association phone interviewed a random sample of 1205 young adults in Hong Kong in 2022 (male sex: 613/1205, 50.9%; mean age 23.0 years, SD 2.86 years) on lifetime OSEs, demographic and family characteristics, Patient Health Questionnaire-4 (PHQ-4) scores, sex-related factors (sexual orientation, sex knowledge, and sexual risk behaviors), and behavioral health outcomes (sexually transmitted infections [STIs], drug use, and suicidal ideation) in the past year. Sample heterogeneity of OSEs was analyzed via latent class analysis with substantive checking of the class profiles. Structural equation modeling was used to examine the direct and indirect associations between the OSE class and behavioral health outcomes via sexual risk behaviors and PHQ-4 scores.

RESULTS

The data supported 3 latent classes of OSEs with measurement invariance by sex. In this study, 33.1% (398/1205), 56.0% (675/1205), and 10.9% (132/1205) of the sample were in the abstinent class (minimal OSEs), normative class (occasional OSEs), and active class (substantive OSEs), respectively. Male participants showed a lower prevalence of the abstinent class (131/613, 21.4% versus 263/592, 44.4%) and a higher prevalence of the active class (104/613, 17.0% versus 28/592, 4.7%) than female participants. The normative class showed significantly higher sex knowledge than the other 2 classes. The active class was associated with male sex, nonheterosexual status, higher sex desire and PHQ-4 scores, and more sexual risk behaviors than the other 2 classes. Compared with the nonactive (abstinent and normative) classes, the active class was indirectly associated with higher rates of STIs (absolute difference in percentage points [Δ]=4.8%; P=.03) and drug use (Δ=7.6%; P=.001) via sexual risk behaviors, and with higher rates of suicidal ideation (Δ=2.5%; P=.007) via PHQ-4 scores.

CONCLUSIONS

This study provided the first results on the 3 (abstinent, normative, and active) latent classes of OSEs with distinct profiles in OSEs, demographic and family characteristics, PHQ-4 scores, sex-related factors, and behavioral health outcomes. The active class showed indirect associations with higher rates of STIs and drug use via sexual risk behaviors and higher rates of suicidal ideation via PHQ-4 scores than the other 2 classes. These results have implications for the formulation and evaluation of targeted interventions to help young adults.

Application of machine learning algorithms in predicting HIV infection among men who have sex with men: Model development and validation

Background

Continuously growing of HIV incidence among men who have sex with men (MSM), as well as the low rate of HIV testing of MSM in China, demonstrates a need for innovative strategies to improve the implementation of HIV prevention. The use of machine learning algorithms is an increasing tendency in disease diagnosis prediction. We aimed to develop and validate machine learning models in predicting HIV infection among MSM that can identify individuals at increased risk of HIV acquisition for transmission-reduction interventions.

Methods

We extracted data from MSM sentinel surveillance in Zhejiang province from 2018 to 2020. Univariate logistic regression was used to select significant variables in 2018-2019 data (P < 0.05). After data processing and feature selection, we divided the model development data into two groups by stratified random sampling: training data (70%) and testing data (30%). The Synthetic Minority Oversampling Technique (SMOTE) was applied to solve the problem of unbalanced data. The evaluation metrics of model performance were comprised of accuracy, precision, recall, F-measure, and the area under the receiver operating characteristic curve (AUC). Then, we explored three commonly-used machine learning algorithms to compare with logistic regression (LR), including decision tree (DT), support vector machines (SVM), and random forest (RF). Finally, the four models were validated prospectively with 2020 data from Zhejiang province.

Results

A total of 6,346 MSM were included in model development data, 372 of whom were diagnosed with HIV. In feature selection, 12 variables were selected as model predicting indicators. Compared with LR, the algorithms of DT, SVM, and RF improved the classification prediction performance in SMOTE-processed data, with the AUC of 0.778, 0.856, 0.887, and 0.942, respectively. RF was the best-performing algorithm (accuracy = 0.871, precision = 0.960, recall = 0.775, F-measure = 0.858, and AUC = 0.942). And the RF model still performed well on prospective validation (AUC = 0.846).

Conclusion

Machine learning models are substantially better than conventional LR model and RF should be considered in prediction tools of HIV infection in Chinese MSM. Further studies are needed to optimize and promote these algorithms and evaluate their impact on HIV prevention of MSM.

Post-lockdown Rebounding High-risk Behaviors and HIV Testing Among MSM in China in the Era of the COVID-19 Pandemic

BACKGROUND

Lockdown measures for controlling the COVID-19 epidemic were enforced in China between January and May 2020. Previous studies showed a decrease in HIV high- Risk Behaviors (HRBs) and updated testing during the lockdown, but little is known about these behaviors during the post-lockdown period.

OBJECTIVE

We conducted quantitative and qualitative assessments of HIV-related behaviors among MSM during the lockdown and post-lockdown periods in Changsha, south-central China.

METHODS

Face-to-face structured interviews with open-ended questions were conducted using the TimeLine Follow Back (TLFB) method for collecting retrospective data on frequencies of HRBs and testing. McNemar's Chi-square test and Wilcoxon signed-rank test were used to comparing frequencies of behaviors between lockdown (January-May 2020) and post-lockdown periods (June- October 2020). Content analysis was used to analyze qualitative data on the reasons for rebounding HRBs and testing.

RESULTS

Of 159 MSM participants, 64% had at least one HRB during the post-lockdown period. Men had increased condomless sex (from 24% to 35%), multiple partners (23% to 35%), and substance abuse (16% to 27%) between the two study periods due to the negative emotions and increased use of social networks during the lockdown. HIV testing frequency also increased from 37% to 66% due to resuming routine testing services in the community-based organizations and increased HRBs among MSM during post-lockdown.

CONCLUSION

After lifting the lockdown measures, MSM had rebounding HRBs and uptake of testing. Effective preventive measures and healthcare services should be available to MSM after the lockdown measures are lifted.