Russia (2008): HIV/AIDS TRaC Study of Risk, Health-seeking Behaviors, and Their Determinants, Among Men Who Have Sex with Men in Eight Regions of the Russian Federation. Second Round.

Description of Intervention: PSI's LaSky program targeting MSM combines the distribution of informational and motivational materials to the target group with outreach activities, "edutainment" group sessions and inter-personal communications delivered by trained peer educators and opinion leaders. LaSky also supports an internet site with information, and a counseling telephone hotline.Methodology: The baseline survey in 2006 used time-location sampling; due to low response rates the follow-up in 2008 used respondent-driven sampling (RDS). Sample size was calculated for all the regions together. The baseline was a single-stage cluster sample, with locations where MSM congregate defined as clusters. The number of respondents to be selected was proportionate to cluster size. In every region the estimates of the number of MSM per cluster were calculated as a part of mapping exercise conducted prior to data collection. The follow-up in 2008 used the clusters defined in 2006 to select seeds (initial respondents). In large metropolitan centers (where the estimated number of total MSM in more than 20,000) four recruitment waves were completed. In smaller locations the estimated number of MSM is below 10,000, and three recruitment waves were completed. A total of 539 and 1113 interviews respectively were completed for the baseline and follow-up studies. Analyses consisted of logistic regression and anovas to examine trends over time, to ascertain which determinants are correlated with key behaviors, and to examine the association between program exposure and changes in health behaviors and determinants. Socio-demographic characteristics and geographic location were controlled for in the analyses.Main FindingsThe monitoring table highlights that:The share of respondents who report having relationships with a permanent partner has reached 82.0%, up from 68.3% two years ago (p value less than .001). Yet the number of respondents reporting having casual partners has also increased (p value less than .05), which suggests that MSM tend to maintain multiple sexual relationships at any given time.Condom use is far from being universal and varies by type of partner. In 2008, condom use at last sex with casual partners was 66.8%, and it was only 44.1% with permanent partners. The findings show a significant improvement in condom use among casual partners over time, but no change in condom use with permanent partners.The results of segmentation analysis indicate that the probability of MSM using condom during last contact with male partner increases with availability of free condoms. Almost 85% of those practicing safe sex report having received condoms for free, the respective figure for non-users is 77% (p value less than .01). Thus, the availability of free condoms encourages MSM to use condoms.Self-efficacy to discuss condom use. MSM who are confident in their ability to discuss condom use with different types of partners are more likely to use condoms at last sex with a male partner. The respective means are 2.86 for users and 2.58 for non-users (p value less than .001).Perception of condoms making sex less pleasant. Predictably, respondents who disagree with the statement "condoms make sex less pleasant" are more likely to use condoms than those who subscribe to this notion (45% vs. 30.2%, respectively, p value less than .001).The results of evaluation analysis reveal that PSI program exposure is associated with:An increase in condom use with casual partners as well as commercial partners (p value less than .05).A greater likelihood of being tested for STIs (p value less than .05).Increased confidence to negotiate condom use with different types of partners, being better informed about the requirement for HIV test being accompanied by pre-and post-test counseling, and knowing that it is not possible to tell by looking if a person has an STI (p value less than .05).A higher perception of being at risk for HIV (p value less than .05).There was no effect on the perception that condoms make sex less pleasant

Goal-Driven Query Answering for Existential Rules with Equality

Inspired by the magic sets for Datalog, we present a novel goal-driven approach for answering queries over terminating existential rules with equality (aka TGDs and EGDs). Our technique improves the performance of query answering by pruning the consequences that are not relevant for the query. This is challenging in our setting because equalities can potentially affect all predicates in a dataset. We address this problem by combining the existing singularization technique with two new ingredients: an algorithm for identifying the rules relevant to a query and a new magic sets algorithm. We show empirically that our technique can significantly improve the performance of query answering, and that it can mean the difference between answering a query in a few seconds or not being able to process the query at all