Respondent-driven Sampling Approach Research Articles

Innovative Strategies for Remotely Sampling Hard-to-Reach Populations: Assessing Phone Versus Internet Respondent-Driven Sampling Approaches Among Venezuelan Refugees and Migrants in Colombia.

It is challenging to quantitatively measure the health vulnerability and risk factors of refugees and migrants residing outside of formal settlement settings. For hard-to-reach populations without available sampling frames, researchers have increasingly turned to novel sampling and statistical methods, like respondent-driven sampling (RDS). "Standard" RDS is typically conducted face-to-face at fixed sites. However, during the coronavirus disease 2019 (COVID-19) pandemic, face-to-face survey methods and recruitment approaches posed high potential risk of virus transmission and infection, making remote RDS approaches optimal. In this paper, we explore the feasibility of implementing telephone and Internet RDS strategies to assess challenges faced by Venezuelan refugees and migrants in the city of Bogotá, Colombia's capital, and the department of Norte de Santander, the main Venezuelan-Colombian border crossing site. We describe RDS assumptions, survey design, formative research, and the implementation of both strategies and present diagnostics for determining whether assumptions are met. Phone-based recruitment strategies in both locations and the Internet strategy in Bogotá achieved their calculated sample size; however, the Internet strategy in Norte de Santander did not. Most RDS assumptions were sufficiently met at sites where sample sizes were reached. These surveys provide valuable lessons for implementing innovative remote strategies with which to study hard-to-reach populations such as refugees and migrants.

Characterizing people who inject drugs with no history of opioid agonist therapy uptake in Iran: Results from a national bio-behavioural surveillance survey in 2020.

Injection drug use is the primary driver of the human immunodeficiency virus HIV epidemic in Iran. We characterized people who inject drugs (PWID) living in Iran who had never received opioid agonist therapy (OAT) and examined barriers to OAT uptake. We recruited 2,684 PWID with a history of drug injection in the previous 12 months using a respondent-driven sampling approach from 11 geographically dispersed cities in Iran. The primary outcome was no lifetime uptake history of OAT medications. The lifetime prevalence of no history of OAT uptake among PWID was 31.3%, with significant heterogeneities across different cities. In the multivariable analysis, younger age, high school education or above, no prior incarceration history, and shorter length of injecting career was significantly and positively associated with no history of OAT uptake. Individual-level barriers, financial barriers, and system-level barriers were the main barriers to receiving OAT. PWID continue to face preventable barriers to accessing OAT, which calls for revisiting the OAT provision in Iran.

Factors Associated With Syphilis Transmission and Acquisition Among Men Who Have Sex With Men: Protocol for a Multisite Egocentric Network Study.

In the United States, the rates of primary and secondary syphilis have increased more rapidly among men who have sex with men (MSM) than among any other subpopulation. Rising syphilis rates among MSM reflect changes in both individual behaviors and the role of sexual networks (eg, persons linked directly or indirectly by sexual contact) in the spread of the infection. Decades of research examined how sexual networks influence sexually transmitted infections (STIs) among MSM; however, few longitudinal data sources focusing on syphilis have collected network characteristics. The Centers for Disease Control and Prevention, in collaboration with 3 sites, enrolled a prospective cohort of MSM in 3 US cities to longitudinally study sexual behaviors and STIs, including HIV, for up to 24 months. The Network Epidemiology of Syphilis Transmission (NEST) study aimed to collect data on the factors related to syphilis transmission and acquisition among MSM. The NEST study was a prospective cohort study that enrolled 748 MSM in Baltimore, Maryland; Chicago, Illinois; and Columbus, Ohio. NEST recruitment used a combination of convenience sampling, venue-based recruitment, and respondent-driven sampling approaches. At quarterly visits, participants completed a behavioral questionnaire and were tested for syphilis, HIV, gonorrhea, and chlamydia. The participants also provided a list of their sexual partners and described their 3 most recent partners in greater detail. The NEST participants were enrolled in the study from July 2018 to December 2021. At baseline, the mean age of the participants was 31.5 (SD 9.1) years. More than half (396/727. 54.5%) of the participants were non-Hispanic Black, 29.8% (217/727) were non-Hispanic White, and 8.8% (64/727) were Hispanic or Latino. Multiple recruitment strategies across the 3 study locations, including respondent-driven sampling, clinic referrals, flyers, and social media advertisements, strengthened NEST participation. Upon the completion of follow-up visits in March 2022, the mean number of visits per participant was 5.1 (SD 3.2; range 1-9) in Baltimore, 2.2 (SD 1.6; range 1-8) in Chicago, and 7.2 (SD 2.9; range 1-9) in Columbus. Using a community-based participatory research approach, site-specific staff were able to draw upon collaborations with local communities to address stigma concerning STIs, particularly syphilis, among potential NEST participants. Community-led efforts also provided a forum for staff to describe the NEST study objectives and plans for research dissemination to the target audience. Strategies to bolster data collection during the COVID-19 pandemic included telehealth visits (all sites) and adaptation to self-collection of STI specimens (Baltimore only). Data from NEST will be used to address important questions regarding individual and partnership-based sexual risk behaviors among MSM, with the goal of informing interventions to prevent syphilis in high-burden areas. RR1-10.2196/40095.

Behavioural Risk for HIV, Hepatitis B, and Hepatitis C Infections among a Population of Drug Users and Injectors across Four Regions in Ghana.

Background Blood borne infections such as HIV, Hepatitis B (HBV), and Hepatitis C (HCV) are of great importance to governments and their implementing partners, especially among people who use drugs (PWUD) and people who inject drugs (PWID). Prevalence and determinants of HIV, HBV, and HCV among PWUD and PWID in Ghana are not well established, the significance of this study. Method This assessment was a cross-sectional study implemented via the respondent driven sampling approach. A team of community advisory boards that comprised former users, current users, and civil society organizations were constituted to help in the implementation of the study. The study was conducted in four regions in Ghana. The assessment was based on a representation of populations of PWID and PWUD from the four regions. Efforts were made by the team to ensure adequate representation of women where feasible. A quantitative questionnaire was developed and used to obtain information on the respondents' sociodemographics, sexual behavior, substance use, and biological characteristics. The prevalence of HIV, HBV, and HCV among PWID and PWUD was determined using blood samples. First response and oral quick test for confirmation of HIV positivity were carried out, while SD bioline was used to test for the presence of HBV and HBC. Data were analyzed using the Bayesian generalized linear model via the binomial family of distributions under the logit link function with weak Cauchy and Normal distribution as prior. Results A total of 323 PWUD and PWID participants were interviewed across four regions of Ghana. The overall median age of the respondents was 36 (28, 43) years. The prevalence of HIV, HBV, and HCV infection in the study was 2.5%, 4.6%, and 5.9%, respectively. The prevalence of HIV, HBV, and HCV among drug users was 2.5% (95% CI: 0.7%–4.2%), 4.1% (95% CI: 1.8%–6.2%), and 6.7% (95% CI: 3.9%–9.4%), respectively. Most drug injectors and users started using and injecting drugs at ages less than 20 years and between 20 and 29 years, respectively. Drug users who identified themselves as part of the general population were 66% less likely to be tested HIV positive (POR = 0.34, CrI: 0.12–0.81) compared to sex workers. Part time employment respondents had fivefold odds (POR = 5.50, CrI: 1.20–16.16) of being HBV positive as against full-time employment. Conclusion Most of the injectors and users started drugs at an early age. Drug users and injectors are at higher risk of these infections because of associated risky sexual behaviors and risky injection practices. Harm reduction programs to help addicts who are willing to quit the practice are recommended.

Strategies to Identify and Reach Young Women Who Sell Sex With HIV Prevention and Care Services: Lessons Learnt From the Implementation of DREAMS Services in Two Cities in Zimbabwe.

BackgroundYoung women who sell sex (YWSS), are underserved by available HIV prevention and care services. The Determined, Resilient, Empowered, AIDS-free, Mentored and Safe (DREAMS) Partnership aimed to reduce the risk of HIV acquisition among vulnerable populations of adolescent girls and young women, including YWSS, in 10 sub-Saharan African countries. We describe 2 methods, respondent-driven sampling (RDS) and peer outreach, used to refer YWSS for DREAMS services in Zimbabwe, and compare the characteristics and engagement of YWSS referred to these services by each method. We hypothesized that RDS would identify YWSS at higher risk of HIV and those who were less engaged with HIV prevention and care services than peer outreach.ObjectiveWe aimed to compare respondent-driven sampling and peer outreach in recruiting and referring high-risk populations for HIV prevention and care services.MethodsWe used RDS, a sampling method designed to reach a representative sample of the network of key populations, and peer outreach, a programmatic approach to identify, reach, and refer YWSS for DREAMS between April and July 2017, and January 2017 and July 2018, respectively, in 2 cities in Zimbabwe. For RDS, we conducted detailed mapping to understand sex work typology and geography, and then purposively selected 10 “seed” participants in each city to initiate RDS. For peer outreach, we initiated recruitment through 18 trained and age-matched peer educators using youth-tailored community mobilization. We described the characteristics and service engagement of YWSS who accessed DREAMS services by each referral approach and assessed the association of these characteristics with referral approach using the chi-square test. Analysis was performed with and without restricting the period when RDS took place. We estimated the relative incremental costs of recruiting YWSS using each strategy for referral to DREAMS services.ResultsOverall, 5386 and 1204 YWSS were referred for DREAMS services through peer outreach and RDS, respectively. YWSS referred through RDS were more likely to access DREAMS services compared to YWSS referred through peer outreach (501/1204, 41.6% vs 930/5386, 17.3%; P<.001). Regardless of referral approach, YWSS who accessed DREAMS had similar education levels, and a similar proportion tested HIV negative and reported not using a condom at the last sex act. A higher proportion of YWSS accessing DREAMS through RDS were aged 18-19 years (167/501, 33.3% vs 243/930, 26.1%; P=.004) and more likely to be aware of their HIV status (395/501, 78.8% vs 396/930, 42.6%; P<.001) compared to those accessing DREAMS services through peer outreach. The incremental cost per young woman who sells sex recruited was US $7.46 for peer outreach and US $52.81 for RDS.ConclusionsPeer outreach and RDS approaches can reach and refer high-risk but different groups of YWSS for HIV services, and using both approaches will likely improve reach.International Registered Report Identifier (IRRID)RR2-DOI 10.1186/s12889-018-5085-6

Risk of SARS-CoV-2 infection among front-line healthcare workers in Northeast Brazil: a respondent-driven sampling approach

ObjectivesWe assessed the prevalence of SARS-CoV-2 infection, personal protective equipment (PPE) shortages and occurrence of biological accidents among front-line healthcare workers (HCW).Design, setting and participantsUsing respondent-driven sampling, the study recruited...

Confirming the Reliability and Validity of the Sexual Minority Adolescent Stress Inventory in a National Sample of Sexual Minority Adolescents.

Objective: Sexual minority adolescents (SMA) experience numerous behavioral health disparities, including depression, anxiety, substance use, non-suicidal self-injury, and suicidality. The primary framework to understand these disparities is minority stress theory, which frames this disproportionate burden as the result of discrimination, violence, and victimization in a homophobic culture. Empirical examinations of minority stress among SMA have been limited by lack of diverse samples or validated measures. This study engaged a national community sample of SMA to confirm reliability and validity of the Sexual Minority Adolescent Stress Inventory (SMASI).Method: A national sample of 2,310 SMA aged 14–17 was recruited in the United States through a hybrid social media and respondent-driven sampling approach. Item response theory and confirmatory factor analysis established the psychometric properties of the SMASI in this sample; minority stress was modeled as a latent variable in several regression models to verify criterion and divergent validity.Results: In this national sample (M age = 15.9; 64% female and 60% White), the factor structure of the SMASI and its 11 subscales was confirmed and shown to be invariant by demographic characteristics. Minority stress as measured by the SMASI was significantly associated with all mental and behavioral health outcomes.Conclusions: This study provides evidence that SMASI is a reliable, valid, and important tool for better understanding minority stress and subsequent health and mental health consequences among SMA.

An evaluation of assumptions underlying respondent-driven sampling and the social contexts of sexual and gender minority youth participating in HIV clinical trials in the United States.

IntroductionRespondent‐driven sampling (RDS) has been an effective sampling strategy for HIV research in many settings, but has had limited success among some youth in the United States. We evaluated a modified RDS approach for sampling Black and Latinx sexual and gender minority youth (BLSGMY) and explored how lived experiences and social contexts of BLSGMY youth may impact traditional RDS assumptions.MethodsRDS was implemented in three US cities, Baltimore, Philadelphia and Washington DC, to engage BLSGMY aged 15 to 24 years in HIV prevention or care intervention trials. RDS was modified to include targeted seed recruitment from venues, Internet and health clinics, and provided options for electronic or paper coupons. Qualitative interviews were conducted among a sub‐sample of RDS participants to explore their experiences with RDS. Interviews were coded using RDS assumptions as an analytic framework.ResultsBetween August 2017 and October 2019, 405 participants were enrolled, 1670 coupons were distributed, with 133 returned, yielding a 0.079 return rate. The maximum recruitment depth was four waves among seeds that propagated. Self‐reported median network size was 5 (IQR 2 to 10) and reduced to 3 (IQR 1 to 5) when asked how many peers were seen in the past 30 days. Qualitative interviews (n = 27) revealed that small social networks, peer trust and targeted referral of peers with certain characteristics challenged network, random recruitment, and reciprocity assumptions of RDS. HIV stigma and research hesitancy were barriers to participation and peer referral. Other situational factors, such as phone ownership and access to reliable transportation, reportedly created challenges for referred peers to participate in research.ConclusionsSmall social networks and varying relationships with peers among BLSGMY challenge assumptions that underlie traditional RDS. Modified RDS approaches, including those that incorporate social media, may support recruitment for community‐based research but may challenge assumptions of reciprocal relationships. Research hesitancy and situational barriers are relevant and must be addressed across any sampling method and study design that includes BLSGMY in the United States.

High Risk of SARS-CoV-2 Infection Among Frontline Healthcare Workers in Northeast Brazil: A Respondent-Driven Sampling Approach

Background: The disparities in the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among frontline health care workers (HCWs) and the unique work circumstances are poorly documented for low-and middle-income countries.Methods: We assessed the frequency of SARS-CoV-2 infection, personal protective equipment (PPE) shortages, PPE use, and accidents involving biological material among HCWs in the Recife metropolitan area, Northeast Brazil. Using respondent driven sampling, we included HCWs attending suspected or confirmed COVID-19 patients from May 2020 to February 2021.Findings: We analyzed 1,525 HCWs (527 physicians, 471 registered nurses, 263 nursing assistants/technicians, and 264 physical therapists). Women predominated in all categories (81·1%). Nurses were older and had more comorbidities (hypertension and overweight/obesity) than the other HCWs. The overall prevalence of SARS-CoV-2 infection was 61·8% after adjustment for the cluster random effect, weighted by network, and reference population size. The independent risk factors for a positive RT-PCR test were being a nursing assistant (OR adjusted: 2·56), not always using all recommended PPE in routine practice (ORadj: 2·15), and reporting a splash of biological fluid/respiratory secretion in the eyes (ORadj: 3·37).Interpretation: The high risk of infection among HCWs reflects PPE shortages and younger, possibly less experienced, frontline HCWs. There were disparities in the risk of SARS-CoV-2 infection among HCWs, with nursing assistants being the most vulnerable, possibly due to their longer and frequent contact with COVID-19 patients.Funding Information: This investigation was funded by Health Technology Assessment Institute (IATS) and by MCTIC/CNPq/FNDCT/MS/SCTIE/Decit Nº 07/2020.Declaration of Interests: We declare no competing interests.Ethics Approval Statement: Providing electronic informed consent was mandatory to participate and access the questionnaire. The project was approved by the National Ethics Committee (CONEP; CAAE: 30629220.8.0000.0008).

Optimizing respondent-driven sampling to find undiagnosed HIV-infected people who inject drugs.

We evaluated whether identification of undiagnosed HIV-infected people who inject drugs (PWID) via respondent-driven sampling (RDS) can be enhanced through a precision RDS (pRDS) approach. First, using prior RDS data from PWID in India, we built a prediction algorithm for recruiting undiagnosed HIV-infected PWID. pRDS was tested in Morinda, Punjab where participants were randomly assigned to standard or pRDS. In the standard RDS approach, all participants received two recruitment coupons. For pRDS, the algorithm determined an individual's probability of recruiting an undiagnosed PWID, and individuals received either two (low probability) or five (high probability) coupons. Efficiency in identifying undiagnosed HIV-infected PWID for the RDS approaches was evaluated in two ways: the number needed to recruit (NNR) and identification rate/week. Predictors of recruiting undiagnosed PWID included HIV/HCV infection, network size, syringe services utilization, and injection environment. 1631 PWID were recruited in Morinda. From the standard RDS approach, 615 were recruited, including 39 undiagnosed; from pRDS, 1012 were recruited, including 77 undiagnosed. In pRDS, those with higher predicted probability were more likely to recruit others with HIV/HCV co-infection, undiagnosed and viremic HIV, and who utilized services. pRDS had a significantly higher identification rate of undiagnosed PWID (1.5/week) compared with the standard (0.8/week). The NNR for pRDS (13.1) was not significantly lower than the standard approach (15.8). pRDS identified twice as many undiagnosed and viremic PWID significantly faster than the standard approach. Leveraging RDS or similar network-based strategies should be considered alongside other strategies to ensure meeting UNAIDS targets.

Estimated Number of People who Inject Drugs in Ho Chi Minh City, Vietnam: Findings from a Two-survey Capture—Recapture Population Size Estimation Exercise

BackgroundHIV/AIDS program managers in Ho Chi Minh City (HCMC), Vietnam have always relied on the police reports and the UNAIDS Estimation and Projection Package for population size estimation of People Who Inject Drugs (PWID).MethodsWe used Respondent-driven Sampling (RDS) to implement a two-source capture—recapture study to estimate the population size of PWID in HCMC in 2017. The study was implemented in seven out of 24 districts and included men and women ages 18 years and older who reported injecting illicit drugs in the last 90 days, and who had lived in the city for the past six months. Estimates of the PWID population size for each of the seven districts were calculated accounting for the RDS sampling design. These were then adjusted to account for the district sampling probabilities to give an estimate for HCMC. Chapman two-source capture—recapture estimates of population size, based on simple random sampling assumptions, were also calculated for comparison.ResultsThe estimates resulted in a population size for HCMC of 19,155 [95% Confidence Interval (CI): 17,006–25,039] using the RDS approach and 17,947 (95% CI: 15,968–19,928), using the Chapman approach.ConclusionThe two-survey capture—recapture exercise provided estimates of PWID in HCMC — based on Chapman estimator and RDS approach — are similar. For planning HIV prevention and care service needs among PWID in HCMC, both estimates may need to be taken into consideration together with size estimates from other sources.

HIV Prevalence and Factors Related to HIV Infection Among Transgender Women in Vietnam: A Respondent Driven Sampling Approach.

Transgender women are at higher risk of HIV infection, however, there is a lack of information about HIV infection and related factors among transgender women in Vietnam. From February 2018 to June 2018, 456 transgender women were recruited in the study using Respondent-Driven Sampling technique. Participants completed the computer-based questionnaire and were tested for HIV serostatus. Multivariable logistic regression was used to identify factors related to HIV infection. The prevalence of HIV infection was 77 (16.5%), of which 19 (24.7%) were not aware of their HIV-positive status prior to the study. Factors associated with HIV infection included popper use (aOR 2.01, p = 0.044) and having regular male partner(s) (aOR 0.42, p = 0.006). More efforts are needed to reduce the high prevalence of HIV infection, such as expanding the reach of HIV screening and prevention programs to the transgender women population, particularly for substance users.Electronic supplementary materialThe online version of this article (10.1007/s10461-020-02867-5) contains supplementary material, which is available to authorized users.

Stigma matters: HIV and HIV risk perception among men who have sex with men in Serbia; a qualitative study

As a social determinant of health, stigma is a major barrier to health care access, illness management and completing the treatment. It is attributed both to HIV as a health condition and to the populations at risk of being infected with it. In Serbia, HIV is associated with men who have sex with men (MSM), with a noticeable stigma towards them. Drawing upon a qualitative cross-sectional study, conducted in three Serbian cities, we explore the MSM’s perception of HIV in the context of that social stigma. Using a respondent-driven sampling approach, 62 targeted MSM respondents participated in focus groups discussions and in-depth interviews. We found that the participants’ understandings of the HIV infection, risks and prevention are shaped by stigma. Those MSM who resisted stigma relativised the HIV risk, associating it with the general population and HIV-positive MSMs, believing that HIV, perceived as a chronical illness, was unjustly related to MSM. As one of the main preventive measures, serosorting was based on alleged HIV-positive statuses of potential sexual partners. HIV-negative participants described perceiving HIV-positive MSM as the ones responsible for spreading the virus, since they were concealing their positive status. As a response to stigma, MSM tended to challenge the HIV discourse, shifting it away from MSM onto the general (male) population and HIV positive MSM. Our analysis suggests that stigma resistance may make MSM more susceptible to taking risks. HIV prevention programmes should take the social context of MSM into account and target MSM-related stigma.

Penalty mechanisms for enforcing concessionaire performance in public–private partnership contracts in Nigeria

PurposeThe purpose of this study is to develop penalty measures against concessionaires’ defaults as a mechanism for protecting the interests of parties (public and private) in public–private partnership (PPP) contracts for enhancing project delivery.Design/methodology/approachThe research methodology is a mixed qualitative and quantitative approach. This study commenced with an in-depth literature review, which provided the basis for identification of penalty measures in construction contract management. The qualitative assessment was based on semi-structured face-to-face interviews, which were aimed at identifying the underlying pattern of the penalty measures, and the quantitative assessment was based on a structured questionnaire. In both cases, respondents were stakeholders’ organizations that had been involved in PPP contracts in the southwestern region of Nigeria. These include industrial practitioners from government-based organizations (ministries, agencies, corporations/parastatals, etc.), private developers/concessionaires, law firms, banks, etc. The sample size was selected using a respondent-driven sampling approach, as the comprehensive lists of the participants in PPP contracts are not readily available in the Nigerian construction industry. Responses from the interview were analysed using interpretative phenomenal analysis via ATLAS.ti7. The quantitative data were analysed using percentile for flexibility between “most” and “more” preferred mechanisms.FindingsThis study developed mechanisms that defined the rights of the public party to redress underperformance of PPP contracts consequent to the defaults of the private party. “Step-in-right” and “termination of the contracts” were preferred against specific cases of “delayed execution”, “abandonment of the project”, “bankruptcy of the concessionaire” and “non-compliance with design and specifications”. With respect to “shortfall in performance against established dates”, the results converged on “monetary fine” and diverged on “step-in-right” and “termination of the contracts”.Practical implicationsThe study contributes to literature on mechanisms for enforcing PPP project performance. Besides, defining rights and obligations of the parties in specific events of underperformance of the concessionaires in PPP contracts is a significant step towards the development of standard conditions of contract for managing PPP projects in which the model is being newly adopted.Originality/valueProject management studies on PPP were extended by defining the liabilities that are consequent to the defaults of the private party and the mechanisms for their enforcement.

A preliminary needs assessment of American Indians who inject drugs in northeastern Montana

BackgroundInjection drug use has not been well documented in American Indians living in the USA. American Indian and Alaskan Natives (AI/ANs) show higher rates of substance use compared to the general population, and have historically been subject to a number of risk factors that are known to increase the likelihood of substance use. AI/ANs also experience increased risk for infectious diseases that are transmitted via injection drug use and/or sexual activity. Harm reduction approaches have been shown to be effective for decreasing risk of disease transmission in at-risk populations, and may be well suited for AI/AN injection drug users residing in rural reservation communities. In this study, we aimed to examine the characteristics of American Indians (AI) who use injection drugs (PWUID) in northeastern Montana to identify needs that could be addressed with harm reduction programming.MethodsFor the present study, we used a respondent-driven sampling approach to generate a sample of 51 self-identified male and female injection drug users ≥18 years of age who were American Indians living on the Fort Peck Indian Reservation. Sampling weights were applied to all analyses using Respondent-Driven Sampling Analysis Tool (RDSAT).ResultsThere were no strong recruitment patterns by age, sex, or ethnic identity status of the recruiter or participant, but there were strong within-group recruitment patterns by location within the reservation. The majority of the sample reported initiating substance use before the age of 18. Participants reported significant risk for HIV, hepatitis, and other infectious diseases through their drug use and/or risky sexual behavior. Sixty-five percent reported having reused syringes, and 53% reported drawing from the same filter. Seventy-five percent reported inconsistent condom use during the 3 months preceding the survey, and 53% reported injecting drugs during sex during the 3 months preceding the survey. Only 66% of participants reported having been tested for HIV in the 12 months preceding the survey. The vast majority (98%) of respondents expressed interest in a harm reduction program. Seventy-six percent reported that it was easy or very easy to obtain new syringes.ConclusionsWe documented several risks for blood-borne pathogens, including elevated levels of syringe reuse. Further, we documented significant interest in harm reduction interventions in the present sample of AI/AN injection drug users. Findings suggest a need for increased access to harm reduction programming for AI/AN injection drug users to reduce the transmission of infectious disease and increase access to compassionate care.

Factors influencing the scope of private party’s obligations in concession-based PPP projects in Nigeria

Purpose – Little success had been recorded on concession-based public private partnership contracts in Nigeria for reasons attributable in part to poor assessment of the socio-cultural and economic factors that contribute to the parties’ costs while preparing contract packages. The purpose of this paper is to assess the factors which significantly influence the private party’s obligations and costs in a concession-based contract thereby enhancing the robust assessment of contract packages when bidding by private investors. Design/methodology/approach – The assessment was based on primary data obtained through questionnaire survey. Structured questionnaire was administered on professionals comprising architects, estate surveyors, quantity surveyors, engineers and builders, accountants/bankers/economists and lawyers who had been involved in concession-based contracts in the Southwestern Nigeria, selected using respondent-driven sampling approach. Factors evaluated were those identified through in-depth literature review and brainstorming of those pertinent to concession transaction in Nigeria. Data collected were analysed using descriptive statistics including mean, relative significance index, impact weighting and factor analysis. Findings – Significant factors that influence private party’s cost were found to be political interference, delay in land acquisition, variation to the contract and non-availability of supportive infrastructure. Originality/value – Findings provided information for structuring concession contract for effective management of country-specific characteristics in concession contract. The understanding of the factors that affect private party’s obligations and costs would guide effective assessment of concession contract in developing economies by foreign investors. Moreover, the study provided implication for the understating of country-specific factors affecting concession contract in Nigeria which would contribute to robust assessment of contract packages when bidding by private investors.

Benchmarking parties’ obligations in the execution of concession-based PPP projects in Nigeria

Purpose Demand–supply matrices with adverse consequences has occasioned government response to concession initiatives in infrastructure in Nigeria. However, concession-based projects have been trailed by administrative and legal controversies. While this scenario has negatively impacted the acceptability of a concession contract, there is, nevertheless, a paucity of research effort aimed at developing a sustainable framework. The purpose of this paper is to develop a conceptual framework for the evaluation and allocation of obligations of parties, thereby enhancing the synergy and cooperation between the public and private sector organization. Design/methodology/approach Data were obtained through a questionnaire administered to professionals in concession-based contracts in southwestern Nigeria, which included architects, estate surveyors, quantity surveyors, engineers and builders, accountants/bankers/economists and lawyers. The respondents were selected using random and respondent driven sampling approaches. The questions were structured to ensure that the respondents have appropriate experience in concession-based projects and hold appropriate positions as decision-makers so as to give credence to the collected data. Findings The study identified 47 contractual obligations in the specific context of developing countries. Based on “half-adjusting principle”, 13 of the obligations notably cost of land acquisition and cost of social disturbances were allocated to the public party; 18 of the obligations notably project design and cost of feasibility study were allocated to the private party; and 16 of the obligations including preparation of terms of a contract and relocation of third party facilities were shared by the parties. Originality/value The framework benchmarked the categorization of public and private parties’ obligations in concession-based public–private partnership (PPP) contracts. The study has the implication for the evaluation and allocation of obligations of parties, which could mitigate the risk of failure of PPP projects in relation to the specific context of developing countries.

Homosexuality-related stigma and sexual risk behaviors among men who have sex with men in Hanoi, Vietnam.

This article examined the associations between three forms of homosexuality-related stigma (enacted, perceived, and internalized homosexual stigmas) with risky sexual behaviors, and to describe the mechanisms of these associations, among men who have sex with men (MSM) in Hanoi, Vietnam. We used respondent-driven sampling (RDS) to recruit 451 MSM into a cross-sectional study conducted from August 2010 to January 2011. Data were adjusted for recruitment patterns due to the RDS approach; logistic regression and path analyses were performed. Participants were young and single; most had attended at least some college. Nine out of ten participants engaged in sexual behaviors at moderate to high risk levels. Compared to those who had no enacted homosexual stigma, men having low and high levels of enacted homosexual stigma, respectively, were 2.23 times (95% CI 1.35-3.69) and 2.20 times (95% CI 1.04-4.76) more likely to engage in high levels of sexual risk behaviors. In addition, there was an indirect effect of perceived homosexual stigma and internalized homosexual stigma on sexual risk behaviors through depression and drug and alcohol use. Our study provides valuable information to our understanding of homosexual stigma in Vietnam, highlighting the need for provision of coping skills against stigma to the gay community and addressing drinking and drug use among MSM, to improve the current HIV prevention interventions in Vietnam.

Understanding recruitment: outcomes associated with alternate methods for seed selection in respondent driven sampling

BackgroundRespondent driven sampling (RDS) was designed for sampling “hidden” populations and intended as a means of generating unbiased population estimates. Its widespread use has been accompanied by increasing scrutiny as researchers attempt to understand the extent to which the population estimates produced by RDS are, in fact, generalizable to the actual population of interest. In this study we compare two different methods of seed selection to determine whether this may influence recruitment and RDS measures.MethodsTwo seed groups were established. One group was selected as per a standard RDS approach of study staff purposefully selecting a small number of individuals to initiate recruitment chains. The second group consisted of individuals self-presenting to study staff during the time of data collection. Recruitment was allowed to unfold from each group and RDS estimates were compared between the groups. A comparison of variables associated with HIV was also completed.ResultsThree analytic groups were used for the majority of the analyses–RDS recruits originating from study staff-selected seeds (n = 196); self-presenting seeds (n = 118); and recruits of self-presenting seeds (n = 264). Multinomial logistic regression demonstrated significant differences between the three groups across six of ten sociodemographic and risk behaviours examined. Examination of homophily values also revealed differences in recruitment from the two seed groups (e.g. in one arm of the study sex workers and solvent users tended not to recruit others like themselves, while the opposite was true in the second arm of the study). RDS estimates of population proportions were also different between the two recruitment arms; in some cases corresponding confidence intervals between the two recruitment arms did not overlap. Further differences were revealed when comparisons of HIV prevalence were carried out.ConclusionsRDS is a cost-effective tool for data collection, however, seed selection has the potential to influence which subgroups within a population are accessed. Our findings indicate that using multiple methods for seed selection may improve access to hidden populations. Our results further highlight the need for a greater understanding of RDS to ensure appropriate, accurate and representative estimates of a population can be obtained from an RDS sample.

Exploring barriers to 'respondent driven sampling' in sex worker and drug-injecting sex worker populations in Eastern Europe.

Respondent driven sampling (RDS) has been used in several counties to sample injecting drug users, sex workers (SWs) and men who have sex with men and as a means of collecting behavioural and biological health data. We report on the use of RDS in three separate studies conducted among SWs between 2004 and 2005 in the Russian Federation, Serbia, and Montenegro. Findings suggest that there are limitations associated with the use of RDS in SW populations in these regions. Findings highlight three main factors that merit further investigation as a means of assessing the feasibility and appropriateness of RDS in this high risk population: the network characteristics of SWs; the appropriate level of participant incentives; and lack of service contact. The highly controlled and hidden nature of SW organizations and weak SW social networks in the region can combine to undermine assumptions underpinning the feasibility of RDS approaches and potentially severely limit recruitment. We discuss the implications of these findings for recruitment and the use of monetary and non-monetary incentives in future RDS studies of SW populations in Eastern Europe.