***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: Abstract Objective : To determine the effectiveness of a brief cognitive behavioural intervention in reducing the incidence of sexually transmitted infections among gay men . Design : R and omised controlled trial with 12 months ' follow up . Setting : Sexual health clinic in London . Participants : 343 gay men with an acute sexually transmitted infection or who reported having had unprotected anal intercourse in the past year . Main outcome measures : Number of new sexually transmitted infections diagnosed during follow up and self reported incidence of unprotected anal intercourse . Results : 72 % ( 361/499 ) of men invited to enter the study did so . 90 % ( 308/343 ) of participants returned at least one follow up question naire or re-attended the clinic and requested a check up for sexually transmitted infections during follow up . At baseline , 37 % ( 63/172 ) of the intervention group and 30 % ( 50/166 ) of the control group reported having had unprotected anal intercourse in the past month . At 12 months , the proportions were 27 % ( 31/114 ) and 32 % ( 39/124 ) respectively ( P=0.56 ) . However , 31 % ( 38/123 ) of the intervention group and 21 % ( 35/168 ) of controls had had at least one new infection diagnosed at the clinic ( adjusted odds ratio 1.66 , 95 % confidence interval 1.00 to 2.74 ) . Considering only men who requested a check up for sexually transmitted infections , the proportion diagnosed with a new infection was 58 % ( 53/91 ) for men in the intervention group and 43 % ( 35/81 ) for men in the control group ( adjusted odds ratio 1.84 , 0.99 to 3.40 ) . Using a regional data base that includes information from 23 sexual health clinics in London , we determined that few participants had attended other sexual health clinics . Conclusions : This behavioural intervention was acceptable and feasible to deliver , but it did not reduce the risk of acquiring a new sexually transmitted infection among these gay men at high risk . Even carefully design ed interventions should not be assumed to bring benefit . It is important to evaluate their effects in r and omised trials with objective clinical end points . What is already known on this topic The need for effective HIV prevention strategies based on reducing sexual risk behaviour remains important Few interventions to reduce sexual risk behaviour have been rigorously evaluated using r and omised controlled trials What this study adds This is the first r and omised controlled trial of an intervention addressing sexual behaviour in homosexual men that uses sexually transmitted infections and self reported behaviour as end points The intervention was brief and feasible to use in a busy clinic , but it did not reduce the risk of participants acquiring new infections The potential for behavioural interventions to do more harm than good needs to be taken OBJECTIVES This study evaluated a theory-based community-level intervention to promote progress toward consistent condom and bleach use among selected population s at increased risk for HIV infection in 5 US cities . METHODS Role-model stories were distributed , along with condoms and bleach , by community members who encouraged behavior change among injection drug users , their female sex partners , sex workers , non-gay-identified men who have sex with men , high-risk youth , and residents in areas with high sexually transmitted disease rates . Over a 3-year period , cross-sectional interviews  ( n = 15,205 ) were conducted in 10 intervention and comparison community pairs . Outcomes were measured on a stage-of-change scale . Observed condom carrying and intervention exposure were also measured . RESULTS At the community level , movement toward consistent condom use with main ( P < .05 ) and nonmain ( P < .05 ) partners , as well as increased condom carrying ( P < .0001 ) , was greater in intervention than in comparison communities . At the individual level , respondents recently exposed to the intervention were more likely to carry condoms and to have higher stage-of-change scores for condom and bleach use . CONCLUSIONS The intervention led to significant communitywide progress toward consistent HIV risk reduction BACKGROUND Effective interventions are needed to prevent acquisition of HIV infection in men who have sex with men . To date , no behavioural interventions specifically for this risk group have been tested with HIV infection as the primary outcome . METHODS This multisite two-group r and omised controlled phase IIb trial tested the efficacy of a behavioural intervention in preventing HIV infection among 4295 men who have sex with men . The experimental intervention consisted of ten one-on-one counselling sessions followed by maintenance sessions every 3 months . The st and ard condition was twice-yearly Project RESPECT individual counselling . Twice-yearly follow-up visits included testing for HIV antibody and assessment of behavioural outcomes . FINDINGS The rate of acquisition of HIV infection was 18.2 % ( 95 % CI -4.7 to 36.0 ) lower in the intervention group than the st and ard group . Adjustment for baseline covariates attenuated the intervention effect to 15.7 % ( -8.4 to 34.4 ) . The effect was more favourable in the first 12 - 18 months of follow-up . The occurrence of unprotected receptive anal intercourse with HIV-positive and unknown-status partners was 20.5 % ( 10.9 to 29.0 ) lower in the intervention than in the st and ard group . INTERPRETATION The results from the primary analyses allow us to rule out that the experimental intervention is associated with a 35 % lower rate of HIV acquisition than in the st and ard group . The overall estimate of a difference of 18.2 % , more favourable estimates of effect in the first 12 - 18 months , and similar effects on risk behaviours suggest that prevention of HIV infection among men who have sex with men by a behavioural intervention is feasible . Further work should be done to develop more effective interventions BACKGROUND As many as one in three HIV-positive people continue unprotected sexual practice s after learning that they are HIV infected . This article reports the outcomes of a theory-based intervention to reduce risk of HIV transmission for people living with HIV infection . METHODS Men ( n=233 ) and women ( n=99 ) living with HIV-AIDS were r and omly assigned to receive either ( 1 ) a five-session group intervention focused on strategies for practicing safer sexual behavior , or ( 2 ) a five-session , contact-matched , health-maintenance support group ( st and ard-of-care comparison ) . Participants were followed for 6 months post-intervention . RESULTS The intervention to reduce risk of HIV transmission result ed in significantly less unprotected intercourse and greater condom use at follow-up . Transmission-risk behaviors with non-HIV-positive sexual partners and estimated HIV transmission rates over a 1-year horizon were also significantly lower for the behavioral risk-reduction intervention group . CONCLUSIONS This study is among the first to demonstrate successful HIV-transmission risk reduction result ing from a behavioral intervention tailored for HIV-positive men and women Testing behavioral interventions to increase safer sex practice s of HIV+ individuals has the potential to significantly reduce the number of new infections . This study evaluated a behavioral intervention design ed to reduce the sexual risk behaviors of HIV+ individuals . HIV+ individuals ( N = 387 ) who reported engaging in unprotected sex with HIV- or partners of unknown serostatus were r and omly assigned to ( a ) a single counseling session targeting problem areas identified by the participant in 3 possible intervention domains ( i.e. , condom use , negotiation , disclosure ) ; ( b ) a single-session comprehensive intervention that covered all 3 intervention domains ; ( c ) the same comprehensive intervention , plus 2 monthly booster sessions ; or ( d ) a 3-session diet and exercise attention-control condition . The median number of unprotectedsex acts decreasedfrom 14 at baseline to6 , 6 , and 4 at 4- , 8- , and 12-month follow-ups , respectively . A repeated measures analysis of variance revealed a significant decrease in unprotected sex acts across all groups across time . A significant Group x Time interaction revealed that the comprehensive-with-boosters group had the most unprotected sex at 8-month follow-up as compared to the other 3 groups . These findings suggest that a brief intervention can result in large reductions in HIV transmission risks among HIV+ individuals , but the relative benefit of one intervention approach over another remains unclear At the time of this writing , no r and omized controlled trial ( RCT ) of an intervention to reduce unsafe sex among Latino gay and bisexual men ( LGBM ) had been published . We report the results of an RCT conducted in New York City in which 180 LGBM were assigned either to an intervention developed specifically for this population or to a wait-list control group . The intervention was based on empowerment theory and used factors identified in prior research as determinants of unsafe sex . By eligibility criteria , all men had engaged in unprotected anal intercourse ( UAI )  within two months of the baseline assessment . At first ( two months ) and second ( six months later ) follow-up assessment s , approximately half of the men in the experimental group reported no UAI . Yet , a similar proportion of the control group also reported no UAI . Baseline data indicate that although the men had been the subject of social oppression and sexual prejudice ( homophobia ) , they did not feel disempowered , externally controlled or fatalistic , and they reported self-efficacy and intentionality to enact safer sex . Lessons learned are discussed , as well as notes of caution for future research employing a similar conceptual framework Objective : To test the efficacy of brief , safer-sex counseling by medical providers of HIV-positive patients during medical visits . Setting : Six HIV clinics in California . Design : Clinics were r and omized to intervention arms evaluated with cohorts of r and omly selected patients measured before and after the intervention . Participants : Five-hundred and eighty-five HIV-positive persons , sexually active prior to enrollment . Interventions : Prevention counseling from medical providers supplemented with written information . Two clinics used a gain-framed approach ( positive consequences of safer-sex ) , two used a loss-frame approach ( negative consequences of unsafe sex ) , and two were attention-control clinics ( medication adherence ) . Interventions were given to all patients who attended the clinics . Outcome measure : Self-reported unprotected anal or vaginal intercourse ( UAV ) . Results : Among participants who had two or more sex partners at baseline , UAV was reduced 38 % ( P < 0.001 ) among those who received the loss-frame intervention . UAV at follow-up was significantly lower in the loss-frame arm [ odds ratio ( OR ) , 0.42 ; 95 % confidence interval ( CI ) , 0.19–0.91 ; P = 0.03 ] compared with the control arm . Using generalized estimating equations ( GEE ) to adjust for clustering did not change the conclusions ( OR , 0.34 ; 95 % CI , 0.24–0.49 ; P = 0.0001 ) . Similar results were obtained in participants with casual partners at baseline . No effects were seen in participants with only one partner or only a main partner at baseline . No significant changes were seen in the gain-frame arm . Conclusions : Brief provider counseling emphasizing the negative consequences of unsafe sex can reduce HIV transmission behaviors in HIV-positive patients presenting with risky behavioral profiles Objectives : To evaluate the effects of an enhanced peer-led intervention on transmission risk behavior and serostatus disclosure of HIV-seropositive gay and bisexual men . Design : A r and omized intervention trial . Methods : HIV-seropositive gay and bisexual men were recruited from New York City and San Francisco and were r and omly assigned to either a st and ard or an enhanced intervention . The st and ard intervention consisted of one session that provided safer sex information . The enhanced intervention consisted of six sessions and included safer sex information , interactive learning activities , and discussion groups that were facilitated by HIV-seropositive peers . Participants completed audio computer-assisted self interview ( A-CASI ) assessment s at baseline and 3 and 6-month follow-ups . Optional testing for sexually transmitted infections was offered at baseline and the 6-month follow-up . Results : A total of 811 participants met the inclusion criteria for outcome analyses . Of these , 85 and 90 % were retained for the 3 and 6-month follow-ups , respectively . Compared with the st and ard intervention , fewer men assigned to the enhanced intervention reported unprotected receptive anal intercourse with a negative or unknown-serostatus partner at 3 months ( 21 versus 26 % , P < 0.05 ) . However , there were no other significant differences in transmission risk or serostatus disclosure at 3 or 6 months . Conclusion : The enhanced intervention was associated with only a limited reduction in transmission risk at 3 months relative to the st and ard intervention . The characteristics of the intervention that may have reduced its efficacy are identified and directions for future research are suggested 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 
    Output:
    
Across the four included meta-analyses ( 102 studies ; 52 independent studies ) , there was strong and consistent evidence for group- and community-level interventions being associated with reductions in UAI ( 27–30 % and 30 % , respectively ) and increases in condom use amongst MSM , but inconsistent evidence for the effectiveness of individual-level interventions .
Skills-building , trained professionals delivering the training and theory-based interventions were also consistently effective .