短報

<p>Total Sample Size (2009–2015) N = 9023.</p

Measuring the potential role of frailty in apparent declining efficacy of HIV interventions

<p><b>Objective:</b>In recent HIV intervention trials, intervention efficacies appear to decline over time. Researchers have attributed this to “waning,” or a loss of intervention efficacy. Another possible reason is heterogeneity in infection risk or “frailty.” We propose an approach to assessing the impact of frailty and waning on measures of intervention efficacy and statistical power in randomized-controlled trials.</p> <p><b>Methods:</b>Using multiplicative risk reduction, we developed a mathematical formulation for computing disease incidence and the incidence rate ratio (IRR) as a function of frailty and waning. We designed study scenarios, which held study-related factors constant, varied waning and frailty parameters and measured the change in disease incidence, IRR, and statistical power.</p> <p><b>Results:</b>We found that frailty alone can impact disease incidence over time. However, frailty has minimal impact on the IRR. The factor that has the greatest influence on the IRR is intervention efficacy and the degree to which it is projected to wane. We also found that even moderate waning can cause an unacceptable decrease in statistical power while the impact of frailty on statistical power is minimal.</p> <p><b>Discussion:</b>We conclude that frailty has minimal impact on trial results relative to intervention efficacy. Study resources would, therefore, be better spent on efforts to keep the intervention efficacy constant throughout the trial (e.g., enhancing the vaccine schedule or promoting treatment adherence).</p

Awareness of PrEP and Willingness to Prescribe PrEP to Persons with Selected Risks for HIV Acquisition by Provider Type, DocStyles, 2009–2015, United States.

<p>Awareness of PrEP and Willingness to Prescribe PrEP to Persons with Selected Risks for HIV Acquisition by Provider Type, DocStyles, 2009–2015, United States.</p

Awareness of PrEP and Willingness to Prescribe PrEP to Persons with Selected Risks for HIV Acquisition by Survey Year, DocStyles, 2009–2015, United States.

<p>Awareness of PrEP and Willingness to Prescribe PrEP to Persons with Selected Risks for HIV Acquisition by Survey Year, DocStyles, 2009–2015, United States.</p

Association of Clinician Characteristics with Willingness to Prescribe PrEP: DocStyles 2009–2015, United States.

<p>Association of Clinician Characteristics with Willingness to Prescribe PrEP: DocStyles 2009–2015, United States.</p

Characteristics of men who have sex with men– National HIV Behavioral Surveillance System, 20 Cities, United States, 2008 and 2011.

a<p>Includes: American Indian or Alaska Native, Asian, Native Hawaiian or Pacific Islander, other race, or multiple races.</p>b<p>Participants were asked if they had ever told anyone they were attracted to other men (Yes or No).</p>c<p>Venue type refers to the type of venue the participant was recruited from.</p>d<p>Other venues include gyms, restaurants, parks, street locations, social organizations, and other places where MSM congregate.</p

Prevalence and awareness of HIV status among MSM.

<p>(A) HIV prevalence of MSM interviewed in 2008 and 2011 by race/ethnicity. Compared to white MSM, black MSM were nearly twice (PR: 1.99) as likely to be HIV positive. (B) Awareness of HIV infection among MSM interviewed in 2008 and 2011 by race/ethnicity. Compared to white MSM, black MSM were 40% (PR: 0.60) less likely to be aware of their HIV infection status. *PRs (prevalence ratios) based on combined 2008, 2011 data. Separate analysis of 2008 and 2011 data produced similar results for prevalence and awareness in both 2008 and 2011 (not shown). CI: 95% confidence interval.</p

Increases in HIV Testing among Men Who Have Sex with Men — National HIV Behavioral Surveillance System, 20 U.S. Metropolitan Statistical Areas, 2008 and 2011

<div><p>In 2011, 62% of estimated new HIV diagnoses in the United States were attributed to male-to-male sexual contact (men who have sex with men, MSM); 39% of these MSM were black or African American. HIV testing, recommended at least annually by CDC for sexually active MSM, is an essential first step in HIV care and treatment for HIV-positive individuals. A variety of HIV testing initiatives, designed to reach populations disproportionately affected by HIV, have been developed at both national and local levels. We assessed changes in HIV testing behavior among MSM participating in the National HIV Behavioral Surveillance System in 2008 and 2011. We compared the percentages tested in the previous 12 months in 2008 and 2011, overall and by race/ethnicity and age group. In unadjusted analyses, recent HIV testing increased from 63% in 2008 to 67% in 2011 overall (<i>P</i><0.001), from 63% to 71% among black MSM (<i>P</i><0.001), and from 63% to 75% among MSM of other/multiple races (<i>P</i><0.001); testing did not increase significantly for white or Hispanic/Latino MSM. Multivariable model results indicated an overall increase in recent HIV testing (adjusted prevalence ratio [aPR] = 1.07, <i>P</i><0.001). Increases were largest for black MSM (aPR = 1.12, <i>P</i><0.001) and MSM of other/multiple races (aPR = 1.20, <i>P</i><0.001). Among MSM aged 18–19 years, recent HIV testing was shown to increase significantly among black MSM (aPR = 1.20, <i>P</i> = 0.007), but not among MSM of other racial/ethnic groups. Increases in recent HIV testing among populations most affected by HIV are encouraging, but despite these increases, improved testing coverage is needed to meet CDC recommendations.</p></div

Response rates of men who have sex with men– National HIV Behavioral Surveillance System, 20 Cities, United States, 2008 and 2011.

a<p>All men were eligible for participation in NHBS in 2008.</p>b<p>Only men who reported ever having sex with another man were eligible for interview in NHBS in 2011.</p>c<p>Limited to men who reported sex with a man in the past 12 months, had a valid HIV test result, and provided valid interview data.</p

Number of HIV tests in a two-year period among MSM in 2008 and 2011.

<p>During the interview, NHBS participants were asked to report their HIV testing frequency in the two years before interview. Testing twice in a two-year period was used as a proxy for annual testing. The distribution of HIV testing frequency among MSM during the 2 years before interview, shown here, changed from 2008 to 2011 (P<0.001). The percentage of men who tested one time or less in the 2 years before interview (less than annually) decreased from 40% in 2008 to 34% in 2011. The percentage who tested twice in two years (annually) was similar (23% to 22%), while the percentage of men who tested three or more times in two years (more than annually) increased from 37% to 44%.</p