Sampling design and recruitment

Sampling design and recruitment

Each round associated with the IBBSS utilized respondent driven sampling provided towards the concealed nature of MSM and therefore enables contrast between and across rounds. Respondent sampling that is drivenRDS) was described in more detail in past studies 22, 23. Quickly, RDS is a modified chain referral non-random sampling technique of recruitment that adjusts for the non-randomness utilizing a mathematical model that loads each sample recruited 23. Inclusion criteria ended up being male aged 16 years and above with a brief history of oral and/or anal intimate connection with another guy into the six months before the study. Known MSM, designated as “seeds” began the chain regarding the recommendation community and employ vouchers to recruit their peers in to the research. Ten seeds had been selected for each circular and seeds had been diversified by age, academic status and socioeconomic status. In order to avoid an over-representation of MSM with comparable attributes, vouchers restricted to three per recruit was utilized 23, 24. In addition, in order to prevent perform enrollment, just one screener ended up being utilized, just one person ended up being authorized to reimburse MSM that has successfully recruited their peers and only one location was used. Each voucher had been redeemable and yielded N500 approx. $3 USD being a motivation for participating, with one more N500 provided to a recruit for every effective extra participant. Total payment ended up being limited by a maximum settlement of n2000 approximately $12 USD. Sample size when it comes to 2007 IBBSS had been calculated according to a thought HIV prevalence of 15%, a design effectation of 2.0 and degree of accuracy of 0.05. For the 2010 and 2014 IBBSS, test size had been predicted to detect a 10% differ from the round that is subsequent.

Data collection

Structured close-ended interviewer administered questionnaires elicited information on socio-demographic traits, variety of intercourse lovers and intimate danger habits. Interviews had been carried out in MSM friendly companies identified in each one of the research states. Transactional sex ended up being evaluated both with feminine and male lovers. Kind of rectal intercourse practiced ended up being classified as “insertive penile intercourse” or penile that is“receptive” into the past a few months. HIV danger perception had been evaluated by asking MSM you are at risk of infection with HIV? ” with response options being “yes or no”“do you feel. Consistent condom use with intimate lovers during transactional and non-transactional intercourse ended up being examined by asking the concerns “how frequently did you or your male partner make use of a condom each time you had intercourse within the last few 6 months? ” while condom usage at final sex ended up being evaluated because of the concern “the last time you’d anal sex do you or your partner work with a condom? ”. Transactional sex had been evaluated by asking “have you received cash or present in return for sex in the final a few months? ” Penned permission had been acquired from all individuals both for behavioural and biological the different parts of the survey.

Laboratory testing

Detection of HIV during most of the studies had been regularly carried out by fast test utilizing whole bloodstream samples acquired from the hand prick. On the basis of the HIV that is national testing, a synchronous algorithm of Determine (Alere health, United States Of America) and Unigold (Trinity Biotech, Plc, Bray, Ireland) had been utilized to spot HIV sero-positivity while status of discordant tests had been verified if you use Stat Pak (Chembio Diagnostic techniques, ny, United States Of America).

Information administration and analysis

Data from each research state had been entered centrally utilizing CS professional variation 3.2 and 25% of questionnaires underwent double-data entry to make sure information quality. Behavioural and biological information had been connected by research identification that is unique for every participant. Information from each round had been merged and analyzed STATA that is using 14.0 Corporation). Descriptive statistics of demographic, behavioural, and variables that are biological carried out. The Cochran-Armitage Chi Square trend test ended up being used to compare differences when considering categorical factors across various rounds of IBBSS, whilst the Kruskal-Wallis test ended up being utilized to compare variations in constant factors across various rounds of IBBSS. To measure associations between HIV and predictor factors (Tables), bivariate logistic regression analysis had been carried out with p value ?0•2 designated as the cutoff for addition in multivariate logistic regression models. Factors were retained when they attained a p value ?0•05 within the multivariate analysis. The predictor factors had been according to information from literary works that revealed a connection involving the factors and HIV.


Table 1 highlights the sociodemographic data of MSM over the three rounds regarding the IBBSS. An overall total of 897, 1545 and 3611 MSM had been surveyed in 2007, 2010 and 2014 correspondingly. A number of the participants had been aged 20–24 years in 2007 (61%) and 2014 (46%), whilst in 2010, almost half (47%) of this participants had been 25 years or older. Over 85% associated with participants had never ever hitched in each round for the study. Almost all the participants had finished at the least level that is secondary, and also this had been greatest among participants in 2007 with 63per cent followed closely by participants in 2014 (55%).

Intimate danger Behaviours

The median quantity of insertive anal lovers had been constant between 2007 and 2010 with about 50% associated with participants reporting insertive anal sex (IAS) with at the very least two lovers interquartile range (IQR 1–4) within the last few half a year. For receptive anal sex (RAS), a median of two partners that are sexual reported in 2007 whilst it ended up being one partner both in 2010 and 2014. Overall, about a third had engaged in transactional intercourse in 2007 (95% self- confidence period (CI): 30–36%) and 2014 (32–35%), whilst it had been about two-fifths this season (36–41%). Consistent condom use, whenever intercourse ended up being offered increased steadily from 35% (27–44%) to 79per cent (74–83%) between 2007 and 2014. Likewise, constant condom used in the last six months ahead of the study during compensated intimate encounters increased from 35% (30–41%) in 2007 to 61per cent (58–64%) in 2014. For non-commercial lovers, constant condom usage increased from 32per cent (29–36%) in 2007 to 51percent (49–53%) in 2014. For self-reported experiences of sexually transmitted illness (STI), there clearly was a rise from russian brides 7% (5–9%) in 2007 to 15percent (13–17%) this season and 19per cent (17–20%) in 2014.

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