***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective To determine the effects of a behavioural intervention for prevention of HIV and sexually transmitted diseases that identified , trained , and engaged leaders of Roma ( Gypsy ) men 's social networks to counsel their own network members . Design A two arm r and omised controlled trial . Setting A disadvantaged , impoverished Roma settlement in Bulgaria . Participants 286 Roma men from 52 social networks recruited in the community . Intervention At baseline all participants were assessed for HIV risk behaviour , tested and treated for sexually transmitted diseases , counselled in risk reduction , and r and omised to intervention or control groups . Network leaders learnt how to counsel their social network members on risk prevention . Networks were followed up three and 12 months after the intervention to determine evidence of risk reduction . Main outcome measure Occurrence of unprotected intercourse during the three months before each assessment . Results Reported prevalence of unprotected intercourse in the intervention group fell more than in control group ( from 81 % and 80 % , respectively , at baseline to 65 % and 75 % at three months and 71 % and 86 % at 12 months ) . Changes were more pronounced among men with casual partners . Effects remained strong at long term follow-up , consistent with changes in risk reduction norms in the social network . Other measures of risk reduction corroborated the intervention 's effects . Conclusions Endorsement and advice on HIV prevention from the leader of a social network produces well maintained change in the reported sexual practice s in members of that network . This model has particular relevance for health interventions in population s such as Roma who may be distrustful of outsiders . Trial registration Clinical Trials NCT00310973 OBJECTIVES Women in impoverished inner-city neighborhoods are at high risk for contracting HIV . A r and omized , multisite community-level HIV prevention trial was undertaken with women living in 18 low-income housing developments in 5 US cities . METHODS Baseline and 12-month follow-up population risk characteristics were assessed by surveying 690 women at both time points . In the 9 intervention condition housing developments , a community-level intervention was undertaken that included HIV risk reduction workshops and community HIV prevention events implemented by women who were popular opinion leaders among their peers . RESULTS The proportion of women in the intervention developments who had any unprotected intercourse in the past 2 months declined from 50 % to 37.6 % , and the percentage of women 's acts of intercourse protected by condoms increased from 30.2 % to 47.2 % . Among women exposed to intervention activities , the mean frequency of unprotected acts of intercourse in the past 2 months tended to be lower at follow-up ( mean = 4.0 ) than at baseline ( mean = 6.0 ) . These changes were corroborated by changes in other risk indicators . CONCLUSIONS Community-level interventions that involve and engage women in neighborhood-based HIV prevention activities can bring about reductions in high-risk sexual behaviors BACKGROUND Little is known about ways network-level factors that may influence the adoption of combination prevention behaviors among injection networks , or how network-oriented interventions might moderate this behavior change process . METHODS A total of 232 unique injection risk networks in Philadelphia , PA , were r and omized to a  peer educator network-oriented intervention or st and ard of care control arm . Network-level aggregates reflecting the injection networks ' baseline substance use dynamics , social interactions , and the networks exposure to gender- and structural-related vulnerabilities were calculated and used to predict changes in the proportion of network members adopting safer injection practice s at 6-month follow-up . RESULTS At follow-up , safer injection practice s were observed among 46.31 % of a network 's members on average . In contrast , 25.7 % of networks observed no change . Controlling for the effects of the intervention , significant network-level factors influencing network-level behavior change reflected larger sized injection networks ( b=2.20 , p=0.013 ) with a greater proportion of members who shared needles ( b=0.29 , p<0.001 ) and engaged in poly drug use at baseline ( b=6.65 , p=0.021 ) . Changes in a network 's safer injection practice s were also observed for networks with fewer new network members ( b=-0.31 , p=0.008 ) , and for networks whose members were proportionally less likely to have experienced incarceration ( b=-0.20 , p=0.012 ) or more likely to have been exposed to drug treatment ( b=0.17 , p=0.034 ) in the 6-months prior to baseline . A significant interaction suggested the intervention uniquely facilitated change in safer injection practice s among female-only networks ( b=-0.32 , p=0.046 ) . CONCLUSIONS Network-level factors offer insights into ways injection networks might be leveraged to promote combination prevention efforts Objectives : To assess the effect of two health system approaches to distribute HIV self-tests on the number of female sex workers ’ client and nonclient sexual partners . Design : Cluster r and omized controlled trial . Methods : Peer educators recruited 965 participants . Peer educator – participant groups were r and omized 1 : 1 : 1 to one of three arms : delivery of HIV self-tests directly from a peer educator , free facility-based delivery of HIV self-tests in exchange for coupons , or referral to st and ard-of-care HIV testing . Participants in all three arms completed four peer educator intervention sessions , which included counseling and condom distribution . Participants were asked the average number of client partners they had per night at baseline , 1 and 4 months , and the number of nonclient partners they had in the past 12 months ( at baseline ) and in the past month ( at 1 month and 4 months ) . Results : At 4 months , participants reported significantly fewer clients per night in the direct delivery arm ( mean difference −0.78 clients , 95 % CI −1.28 to −0.28 , P = 0.002 ) and the coupon arm ( −0.71 , 95 % CI −1.21 to −0.21 , P = 0.005 ) compared with st and ard of care . Similarly , they reported fewer nonclient partners in the direct delivery arm ( −3.19 , 95 % CI −5.18 to −1.21 , P = 0.002 ) and in the coupon arm ( −1.84 , 95 % CI −3.81 to 0.14 , P = 0.07 ) arm compared with st and ard of care . Conclusion : Expansion of HIV self-testing may have positive behavioral effects enhancing other HIV prevention efforts among female sex workers in Zambia . Trial Registration : Clinical Trials.gov NCT02827240 Background  HIV self-testing ( HIVST ) may play a role in addressing gaps in HIV testing coverage and as an entry point for HIV prevention services . We conducted a cluster r and omized trial of 2 HIVST distribution mechanisms compared to the st and ard of care among female sex workers ( FSWs ) in Zambia . Methods and findings Trained peer educators in Kapiri Mposhi , Chirundu , and Livingstone , Zambia , each recruited 6 FSW participants . Peer educator – FSW groups were r and omized to 1 of 3 arms : ( 1 ) delivery ( direct distribution of an oral HIVST from the peer educator ) , ( 2 ) coupon ( a coupon for collection of an oral HIVST from a health clinic/pharmacy ) , or ( 3 ) st and ard-of-care HIV testing . Participants in the 2 HIVST arms received 2 kits : 1 at baseline and 1 at 10 weeks . The primary outcome was any self-reported HIV testing in the past month at the 1- and 4-month visits , as HIVST can replace other types of HIV testing . Secondary outcomes included linkage to care , HIVST use in the HIVST arms , and adverse events . Participants completed question naires at 1 and 4 months following peer educator interventions . In all , 965 participants were enrolled between September 16 and October 12 , 2016 ( delivery , N = 316 ; coupon , N = 329 ; st and ard of care , N = 320 ) ; 20 % had never tested for HIV . Overall HIV testing at 1 month was 94.9 % in the delivery arm , 84.4 % in the coupon arm , and 88.5 % in the st and ard-of-care arm ( delivery versus st and ard of care risk ratio [ RR ] = 1.07 , 95 % CI 0.99–1.15 , P = 0.10 ; coupon versus st and ard of care RR = 0.95 , 95 % CI 0.86–1.05 , P = 0.29 ; delivery versus coupon RR = 1.13 , 95 % CI 1.04–1.22 , P = 0.005 ) . Four-month rates were 84.1 % for the delivery arm , 79.8 % for the coupon arm , and 75.1 % for the st and ard-of-care arm ( delivery versus st and ard of care RR = 1.11 , 95 % CI 0.98–1.27 , P = 0.11 ; coupon versus st and ard of care RR = 1.06 , 95 % CI 0.92–1.22 , P = 0.42 ; delivery versus coupon RR = 1.05 , 95 % CI 0.94–1.18 , P = 0.40 ) . At 1 month , the majority of HIV tests were self-tests ( 88.4 % ) . HIV self-test use was higher in the delivery arm compared to the coupon arm ( RR = 1.14 , 95 % CI 1.05–1.23 , P = 0.001 ) at 1 month , but there was no difference at 4 months . Among participants reporting a positive HIV test at 1 ( N = 144 ) and 4 months ( N = 235 ) , linkage to care was non-significantly lower in the 2 HIVST arms compared to the st and ard-of-care arm . There were 4 instances of intimate partner violence related to study participation , 3 of which were related to HIV self-test use . Limitations include the self-reported nature of study outcomes and overall high uptake of HIV testing . Conclusions In this study among FSWs in Zambia , we found that HIVST was acceptable and accessible . However , HIVST may not substantially increase HIV cascade progression in context s where overall testing and linkage are already high . Trial registration Clinical Trials.gov Objective : To evaluate the effects of an HIV prevention intervention with social networks of young men who have sex with men ( YMSM ) in St. Petersburg , Russia and Sofia , Bulgaria . Design : A two-arm r and omized trial with a longitudinally-followed community cohort . Methods : Fifty-two MSM social networks were recruited through access points in high-risk community venues . Network members ( n = 276 ) were assessed to determine risk characteristics , administered sociometric measures to empirically identify the social leader of each network , and counseled in risk reduction . The leaders of 25 experimental condition networks attended a nine-session program that provided training and guidance in delivering ongoing theory-based HIV prevention advice to other network members . Leaders successively targeted network members ’ AIDS risk-related knowledge and risk reduction norms , attitudes , intentions , and self-efficacy . Participants were re-administered risk assessment measures at 3- and 12-month follow-ups . Results : Among changes produced , the percentage of experimental network members reporting unprotected intercourse ( UI ) declined from 71.8 to 48.4 % at 3-month follow up ( P = 0.0001 ) . The percentage who engaged in UI with multiple partners reduced from 31.5 to 12.9 % ( P = 0.02 ) . After 12 months , the effects became attenuated but remained among participants who had multiple recent sexual partners , the most vulnerable group . Little change was found in control group networks . Conclusions : Interventions that engage the identified influence leaders of at-risk YMSM social networks to communicate theory-based counseling and advice can produce significant sexual risk behavior change . This model is culturally pertinent for HIV prevention efforts in former socialist countries , as well as elsewhere for other hard-to-reach vulnerable community population Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Background HIV self-testing allows HIV testing at any place and time and without health workers . HIV self-testing may thus be particularly useful for female sex workers ( FSWs ) , who should test frequently but face stigma and financial and time barriers when accessing healthcare facilities . Methods and findings We conducted a cluster-r and omized controlled health systems trial among FSWs in Kampala , Ug and a , to measure the effect of 2 HIV self-testing delivery models on HIV testing and linkage to care outcomes . FSW peer educator groups ( 1 peer educator and 8 participants ) were r and omized to either ( 1 ) direct provision of HIV self-tests , ( 2 ) provision of coupons for free collection of HIV self-tests in a healthcare facility , or ( 3 ) st and ard of care HIV testing .  We r and omized 960 participants in 120 peer educator groups from October 18 , 2016 , to November 16 , 2016 . Participants ’ median age was 28 years ( IQR 24–32 ) . Our prespecified primary outcomes were self-report of any HIV 
    Output:
    
This review provides evidence that SNS can reach key population s who are currently not being reached by existing programmes and deliver HIV interventions through social networks , which decreases HIV sexual risk behaviour and HIV incidence and increases HIV testing uptake and participant retention .