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Abstract Background Economic theory and limited empirical data suggest that costs per unit of HIV prevention program output (unit costs) will initially decrease as small programs expand. Unit costs may then reach a nadir and start to increase if expansion continues beyond the economically optimal size. Information on the relationship between scale and unit costs is critical to project the cost of global HIV prevention efforts and to allocate prevention resources efficiently. Methods The "Prevent AIDS: Network for Cost-Effectiveness Analysis" (PANCEA) project collected 2003 and 2004 cost and output data from 206 HIV prevention programs of six types in five countries. The association between scale and efficiency for each intervention type was examined for each country. Our team characterized the direction, shape, and strength of this association by fitting bivariate regression lines to scatter plots of output levels and unit costs. We chose the regression forms with the highest explanatory power (R2). Results Efficiency increased with scale, across all countries and interventions. This association varied within intervention and within country, in terms of the range in scale and efficiency, the best fitting regression form, and the slope of the regression. The fraction of variation in efficiency explained by scale ranged from 26% – 96%. Doubling in scale resulted in reductions in unit costs averaging 34.2% (ranging from 2.4% to 58.0%). Two regression trends, in India, suggested an inflection point beyond which unit costs increased. Conclusion Unit costs decrease with scale across a wide range of service types and volumes. These country and intervention-specific findings can inform projections of the global cost of scaling up HIV prevention efforts.

Female sex workers (FSW) are a key population in the HIV epidemic and face high levels of violence. While women globally are predominantly at risk of intimate partner violence (IPV), FSW are additionally vulnerable to violence from clients, police, and pimps associated with their occupation. FSW are therefore at risk of cumulative trauma from polyvictimization, or violence from multiple types of perpetrators. Polyvictimization is a driver of morbidity and mortality in numerous populations, but there has been little research on how multiple types of victimization are related to one another in FSW. A cross-sectional survey was conducted among 754 FSW from three cities in the Russian Federation. Surveys assessed lifetime experiences of client, police, intimate partner, and pimp violence. Multivariate log-binomial and Poisson regression were used to test associations between these types of violence. Forty-five percent experienced any type of violence, including 31.7% from clients, 16.0% from police, 15.7% from intimate partners, and 11.4% from pimps. One fifth (20.4%) experienced polyvictimization. Client violence was central to polyvictimization: Only 5.9% of polyvictimization occurs without client violence. When client violence was not present, police, pimp, or IPV co-occurred significantly less than would be expected under an assumption that these types of violence occur independently (p <.001). However, they co-occurred more than would be expected when client violence is present. After adjusting for other types of violence experienced and demographic factors, experiencing client violence was independently associated with police violence (adjusted relative risk [ARR] = 2.77, 95% confidence interval [CI] [1.67, 4.59]), IPV (ARR = 3.67, 95% CI [1.95, 6.89]), and pimp violence (ARR = 5.26, 95% CI [2.80, 9.86]). Client violence may drive exposure to other types of violence and enable polyvictimization in a way that other types of violence do not in this setting. Violence prevention interventions may achieve maximal effect in reducing multiple types of violence by focusing on client violence. [ABSTRACT FROM AUTHOR]

Depression is a major public health problem in the Russian Federation and is particularly of concern for men who have sex with men (MSM). MSM living in Moscow City were recruited via respondent-driven sampling and participated in a cross-sectional survey from October 2010 to April 2013. Multiple logistic regression models compared the relationship between sexual identity, recent stigma, and probable depression, defined as a score of ≥23 on the Center for Epidemiological Studies Depression scale. We investigated the interactive effect of stigma and participation in the study after the passage of multiple "anti-gay propaganda laws" in Russian provinces, municipalities, and in neighboring Ukraine on depression among MSM. Among 1367 MSM, 36.7% (n = 505) qualified as probably depressed. Fifty-five percent identified as homosexual (n = 741) and 42.9% identified as bisexual (n = 578). Bisexual identity had a protective association against probable depression (reference: homosexual identity AOR 0.71; 95%CI 0.52-0.97; p < 0.01). Those who experienced recent stigma (last 12 months) were more likely to report probable depression (reference: no stigma; AOR 1.75; 95%CI 1.20-2.56; p < 0.01). The interaction between stigma and the propaganda laws was significant. Among participants with stigma, probable depression increased 1.67-fold after the passage of the anti-gay laws AOR 1.67; 95%CI 1.04-2.68; p < 0.01). Depressive symptoms are common among MSM in Russia and exacerbated by stigma and laws that deny homosexual identities. Repeal of Russia's federal anti-gay propaganda law is urgent but other social interventions may address depression and stigma in the current context. [ABSTRACT FROM AUTHOR]

Analytically distinct estimators have been proposed for the calculation of population-based estimates derived from respondent-driven sampling (RDS), yet there have been few comparisons of the inferences from these estimators using empirical data. We compared estimates produced by unweighted analysis used to calculate sample proportions and by three available estimators that are used to calculate population proportions, RDS-I, RDS-II (Volz-Heckathorn), and Gile’s RDS-SS. Data were derived from a cross-sectional, RDS study of men who have sex with men (MSM) conducted from October 2010 to April 2013 in Moscow, Russia (N = 1,376, recruitment depth: 31 waves). Analyses investigated the influence of key parameters: recruitment depth, homophily, and network size on sample and population estimates. Variability in results produced by the estimators and recruitment depth were statistically compared using the coefficient of variation (CV). Sample proportions had the least variability across different recruitment depths, compared to the RDS estimators. Population estimates tended to differ at lower recruitment depth but were approximately equal after reaching sampling equilibrium, highlighting the importance of sampling to greater recruitment depth. All estimators incorporate inverse probability weighting using self-reported network size, explaining the similarities in across population estimates and the difference of these estimates relative to sample proportions. Current biases and limitations associated with RDS estimators are discussed. [ABSTRACT FROM AUTHOR]

Background: Economic theory and limited empirical data suggest that costs per unit of HIV prevention program output (unit costs) will initially decrease as small programs expand. Unit costs may then reach a nadir and start to increase if expansion continues beyond the economically optimal size. Information on the relationship between scale and unit costs is critical to project the cost of global HIV prevention efforts and to allocate prevention resources efficiently. Methods: The "Prevent AIDS: Network for Cost- Effectiveness Analysis" (PANCEA) project collected 2003 and 2004 cost and output data from 206 HIV prevention programs of six types in five countries. The association between scale and efficiency for each intervention type was examined for each country. Our team characterized the direction, shape, and strength of this association by fitting bivariate regression lines to scatter plots of output levels and unit costs. We chose the regression forms with the highest explanatory power (R2). Results: Efficiency increased with scale, across all countries and interventions. This association varied within intervention and within country, in terms of the range in scale and efficiency, the best fitting regression form, and the slope of the regression. The fraction of variation in efficiency explained by scale ranged from 26% - 96%. Doubling in scale resulted in reductions in unit costs averaging 34.2% (ranging from 2.4% to 58.0%). Two regression trends, in India, suggested an inflection point beyond which unit costs increased. Conclusion: Unit costs decrease with scale across a wide range of service types and volumes. These country and intervention-specific findings can inform projections of the global cost of scaling up HIV prevention efforts. [ABSTRACT FROM AUTHOR]