Inequities in access to HIV prevention services for transgender men: results of a global survey of men who have sex with men.

INTRODUCTION: Free or low-cost HIV testing, condoms, and lubricants are foundational HIV prevention strategies, yet are often inaccessible for men who have sex with men (MSM). In the global context of stigma and poor healthcare access, transgender (trans) MSM may face additional barriers to HIV prevention services. Drawing on data from a global survey of MSM, we aimed to describe perceived access to prevention services among trans MSM, examine associations between stigma and access, and compare access between trans MSM and cisgender (non-transgender) MSM. METHODS: The 2014 Global Men's Health and Rights online survey was open to MSM (inclusive of trans MSM) from any country and available in seven languages. Baseline data (n=3857) were collected from July to October 2014. Among trans MSM, correlations were calculated between perceived service accessibility and anti-transgender violence, healthcare provider stigma, and discrimination. Using a nested matched-pair study design, trans MSM were matched 4:1 to cisgender MSM on age group, region, and HIV status, and conditional logistic regression models compared perceived access to prevention services by transgender status. RESULTS: About 3.4% of respondents were trans men, of whom 69 were included in the present analysis. The average trans MSM participant was 26 to 35 years old (56.5%); lived in western Europe, North America, or Oceania (75.4%); and reported being HIV-negative (98.6%). HIV testing, condoms, and lubricants were accessible for 43.5, 53.6, and 26.1% of trans MSM, respectively. Ever having been arrested or convicted due to being trans and higher exposure to healthcare provider stigma in the past six months were associated with less access to some prevention services. Compared to matched cisgender controls, trans MSM reported significantly lower odds of perceived access to HIV testing (OR=0.57, 95% CI=0.33, 0.98) and condom-compatible lubricants (OR=0.54, 95% CI=0.30, 0.98). CONCLUSIONS: This first look at access to HIV prevention services for trans MSM globally found that most reported inadequate access to basic prevention services and that they were less likely than cisgender MSM to have access to HIV testing and lubricants. Results indicate the need to enhance access to basic HIV prevention services for trans MSM, including MSM-specific services.

Median filtering in constant time.

The median filter is one of the basic building blocks in many image processing situations. However, its use has long been hampered by its algorithmic complexity of O (r) in the kernel radius. With the trend toward larger images and proportionally larger filter kernels, the need for a more efficient median filtering algorithm becomes pressing. In this correspondence, a new, simple, yet much faster, algorithm exhibiting O (1) runtime complexity is described and analyzed. It is compared and benchmarked against previous algorithms. Extensions to higher dimensional or higher precision data and an approximation to a circular kernel are presented, as well.