Evaluating outcome-correlated recruitment and geographic recruitment bias in a respondent-driven sample of people who inject drugs in Tijuana, Mexico.
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ABSTRACT:
SUBMITTER: Rudolph AE
PROVIDER: S-EPMC4401495 | biostudies-other | 2014 Dec
REPOSITORIES: biostudies-other
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Project description:Background: Epidemiologic surveys of people who inject drugs (PWID) can be difficult to conduct because potential participants may fear exposure or legal repercussions. Respondent-driven sampling (RDS) is a procedure in which subjects recruit their eligible social contacts. The statistical validity of RDS surveys of PWID and other risk groups depends on subjects recruiting at random from among their network contacts. Objectives: We sought to develop and apply a rigorous definition and statistical tests for uniform network recruitment in an RDS survey. Methods: We undertook a detailed study of recruitment bias in a unique RDS study of PWID in Hartford, CT, the USA in which the network, individual-level covariates, and social link attributes were recorded. A total of n=527 participants (402 male, 123 female, and two individuals who did not specify their gender) within a network of 2626 PWID were recruited. Results: We found strong evidence of recruitment bias with respect to age, homelessness, and social relationship characteristics. In the discrete model, the estimated hazard ratios regarding the significant features of recruitment time and choice of recruitee were: alter's age 1.03 [1.02, 1.05], alter's crack-using status 0.70 [0.50, 1.00], homelessness difference 0.61 [0.43, 0.87], and sharing activities in drug preparation 2.82 [1.39, 5.72]. Under both the discrete and continuous-time recruitment regression models, we reject the null hypothesis of uniform recruitment. Conclusions: The results provide the evidence that for this study population of PWID, recruitment bias may significantly alter the sample composition, making results of RDS surveys less reliable. More broadly, RDS studies that fail to collect comprehensive network data may not be able to detect biased recruitment when it occurs.
| S-EPMC7680667 | biostudies-literature
Project description:ObjectiveWe 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.Design/methodsFirst, 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.ResultsPredictors 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).ConclusionpRDS 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.
| S-EPMC7842595 | biostudies-literature
Project description:The HIV epidemic in Malaysia is concentrated among people who inject drugs (PWID). Accurate estimates of HIV prevalence are critical for developing appropriate treatment and prevention interventions for PWID in Malaysia. In 2010, 461 PWID were recruited using respondent-driven sampling in Greater Kuala Lumpur, Malaysia. Participants completed rapid HIV testing and behavioral assessments. Estimates of HIV prevalence were computed for each of the three recruitment sites and the overall sample. HIV prevalence was 15.8 % (95 % CI 12.5-19.2 %) overall but varied widely by location: 37.0 % (28.6-45.4 %) in Kampung Baru, 10.3 % (5.0-15.6 %) in Kajang, and 6.3 % (3.0-9.5 %) in Shah Alam. Recruitment extended to locations far from initial interview sites but was concentrated around discrete geographic regions. We document the high prevalence of HIV among PWID in Greater Kuala Lumpur. Sustained support for community surveillance and HIV prevention interventions is needed to stem the HIV epidemic among PWID in Malaysia.
| S-EPMC4743744 | biostudies-literature
Project description:Background and aimsDespite extensive research on HIV and hepatitis C (HCV) among people who inject drugs (PWID), there remains a gap in knowledge on the burden among women who inject drugs and their unique contexts and risk factors. This analysis compares HIV and HCV prevalence in female and male PWID and estimates injection and sexual risk correlates of prevalent HIV and HCV infection among women in Northeast India.DesignCross-sectional sample accrued using respondent-driven sampling.SettingSeven cities in Northeast India, 2013.ParticipantsA total of 6457 adult PWID.MeasurementsParticipants completed an interviewer-administered survey. HIV infection was diagnosed on-site and HCV antibody testing was performed on stored specimens. HIV and HCV prevalence estimates were stratified by gender. Among women, the association of risk correlates with HIV and HCV were estimated using multi-level logistic regression models.FindingsA total of 796 (15.9%) of the PWID were women, of whom 52.9% [95% confidence interval (CI) = 49.3-56.5%] were HIV-infected and 22.3% (CI = 19.9-24.7%) were HCV-infected. HIV and HCV prevalence among men was 17.4% (CI = 16.9-24.7%) and 30.4% (CI = 31.2-32.0%), respectively. Among women, correlates of HIV were widowhood [adjusted odds ratio (aOR) versus currently married = 4.03, CI = 2.13-7.60] and a higher number of life-time sexual partners (aOR ≥8 versus none = 3.08, CI = 1.07-8.86). Correlates of HCV were longer injection duration (aOR per 10 years = 1.70, CI = 1.25-2.27), injecting only heroin and a combination of drugs (aOR versus pharmaceuticals only = 5.63, CI = 1.68-18.9 and aOR = 2.58, CI = 1.60-4.16, respectively), sharing needles/syringes (aOR = 2.46, CI = 1.29-4.56) and a larger PWID network (aOR ≥ 51 versus 1-5 = 4.17, CI = 2.43-7.17).ConclusionsWomen who inject drugs in Northeast India have a high HIV prevalence, which was more than double their hepatitis C (HCV) prevalence, an opposite pattern than is observed typically among male PWID. HIV infection is associated with sexual risk factors while injection-related behaviors appear to drive HCV infection.
| S-EPMC5503783 | biostudies-literature
Project description:Women who inject drugs are disproportionately affected by HIV and intimate partner violence (IPV); however, the link between IPV and HIV remains under-researched among substance-using women in low- and middle-income countries. This study examined associations and additive effects of different forms of IPV victimization (psychological, physical and/or injurious, and sexual) on HIV sexual risk behavior among women who inject drugs in Indonesia. Respondent-driven sampling (RDS) was used to recruit 731 women from Greater Jakarta and Bandung, West Java. RDS-II weighted prevalence of any past-year IPV was 68.9% (95% CI 65.0, 72.6) in Jakarta and 55.9% (95% CI 48.0, 63.5) in Bandung. In separate logistic regressions controlling for socio-demographic covariates, all three forms of IPV showed statistically significant associations with sexual risk behavior. After adjusting for all IPV types, psychological (OR 1.87; 95% CI 1.17, 2.99; p = 0.009) and sexual (OR 1.98; 95% CI 1.22, 3.21; p = 0.006) IPV independently predicted women's sexual risk behavior. Marginal effects models suggested that co-occurrence of multiple forms of IPV had greater adverse consequences: sexual risk behavior was reported by 64.1% of women who did not experience any IPV, but increased to 89.9% among women exposed to all three types. Comprehensive harm reduction services that integrate IPV monitoring and prevention are urgently needed to reduce both HIV and IPV.
| S-EPMC6154010 | biostudies-literature
Project description:OBJECTIVE:From 2011 to 2013, the Global Fund (GF) supported needle and syringe programmes in Mexico to prevent transmission of HIV among people who inject drugs. It remains unclear how GF withdrawal affected the costs, quality and coverage of needle and syringe programme provision. DESIGN:Costing study and longitudinal cohort study. SETTING:Tijuana, Mexico. PARTICIPANTS:Personnel from a local needle and syringe programme (n=6) and people who inject drugs (n=734) participating in a longitudinal study. PRIMARY OUTCOME MEASURES:Provision of needle and syringe programme services and cost (per contact and per syringe distributed, in 2017 $USD) during GF support (2012) and after withdrawal (2015/16). An additional outcome included needle and syringe programme utilisation from a concurrent cohort of people who inject drugs during and after GF withdrawal. RESULTS:During the GF period, the needle and syringe programme distributed 55 920 syringes to 932 contacts (60 syringes/contact) across 14 geographical locations. After GF withdrew, the needle and syringe programme distributed 10 700 syringes to 2140 contacts (five syringes/contact) across three geographical locations. During the GF period, the cost per harm reduction contact was approximately 10-fold higher compared with after GF ($44.72 vs $3.81); however, the cost per syringe distributed was nearly equal ($0.75 vs $0.76) due to differences in syringes per contact and reductions in ancillary kit components. The mean log odds of accessing a needle and syringe programme in the post-GF period was significantly lower than during the GF period (p=0.02). CONCLUSIONS:Withdrawal of GF support for needle and syringe programme provision in Mexico was associated with a substantial drop in provision of sterile syringes, geographical coverage and recent clean syringe utilisation among people who inject drugs. Better planning is required to ensure harm reduction programme sustainability is at scale after donor withdrawal.
| S-EPMC6352756 | biostudies-literature
Project description:BackgroundPeople who inject drugs (PWID) are the most exposed to hepatitis C virus (HCV). In Thailand, drug use is highly criminalized, and harm reduction services are scarce. This study estimates risky injection practices and assesses the proportion of HCV awareness and screening in the PWID population in Northern Thailand.MethodsWe used respondent-driven sampling (RDS) to recruit PWID in Chiang Mai Province. Social and behavioural data were collected through face-to-face interviews at an addiction treatment facility. Weighted population estimates were calculated to limit biases related to the non-random sampling method. Univariate and multivariate analyses were performed to study factors associated with HCV awareness and screening.ResultsOne hundred seventy-one PWID were recruited between April 2016 and January 2017. Median age was 33 (Interquartile range: 26-40) years, 12.2% were women, and 49.4% belonged to a minority ethnic group. Among participants, 76.8% injected heroin, 20.7% methadone, and 20.7% methamphetamine. We estimate that 22.1% [95% CI: 15.7-28.6] of the population had shared needles in the last 6 months and that 32.0% [95% CI: 23.6-40.4] had shared injection material. Only 26.6% [95% CI: 17.6-35.6] had heard of HCV. Factors independently associated with knowledge of HCV included belonging to a harm reduction organization (adjusted odds ratio (aOR) = 5.5 [95% CI: 2.0-15.3]) and voluntary participation in a drug rehabilitation programme (aOR = 4.3 [95% CI: 1.3-13.9]), while Lahu ethnicity was negatively associated (aOR = 0.3 [95% CI: 0.1-0.9]). We estimate that 5% of the PWID population were screened for HCV; the only factor independently associated with being screened was membership of a harm reduction organization (aOR = 5.7 [95% CI: 1.6-19.9]).ConclusionOur study reveals that the PWID population is poorly informed and rarely screened for HCV, despite widespread risky injection practices. A public health approach aimed at reducing the incidence of HCV should target the PWID population and combine harm reduction measures with information and destigmatization campaigns. Civil society organizations working with PWID are a major asset for the success of such an approach, based on their current positive interventions promoting awareness of and screening for HCV.
| S-EPMC7517806 | biostudies-literature
Project description:BackgroundUkraine, a country of 45.5 million people, has one of the most volatile HIV and HCV epidemics in the world. In this paper, we estimate the prevalence of HIV and HCV among PWID in five Ukrainian cities.MethodsA cross-sectional study was conducted in 2014-2015, based on stratified hybrid sampling with random and respondent driven sampling in five cities: Kyiv, Odesa, Mykolaiv, Dnipro and Lviv. Using data on HIV and HCV antibody testing from 1613 respondents, we evaluate selection bias in the sampling methods by analyzing spatial and network patterns of sampling processes. We develop and apply inverse probability weights in order to estimate the HIV and HCV prevalence in each city, as well as in the overall sample.FindingsThe aggregate HIV prevalence for the five cities is 35.1% (95% CI: 29.5%-38.5%) but this varied considerably by city: in Kyiv the HIV prevalence is 26.6% (95% CI: 20.3.8%-33.4%), in Odesa - 38.2% (95% CI: 29.8% and 47.1%), in Mykolaiv - 42.0% (95% CI: 34.3%-49.2%), in Dnipro - 58.8% (95% CI: 52.2%-65.8%), and in Lviv 24.6% (95% CI: 18.8%-30.8%). The aggregate HCV prevalence estimate for the five cities is 58.6% (95% CI: 54.9%-61.7%). The highest HCV prevalence is estimated in Kyiv - 84.8% (95% CI: 78.5%-90.1%). HCV prevalence in Odesa is the lowest and estimated to be 36.5% (95% CI: 29.5%-45.1%), in Mykolaiv - 49.1% (95% CI: 41.5%-57.0%), in Dnipro - 56.1% (95% CI: 50.3%-63.4%) and in Lviv 38.5% (95% CI: 31.8%-45.0%).ConclusionsMonitoring behavioral and health outcomes of PWID on a regular basis is necessary for determining prevention and treatment priorities for HIV and HCV infections in Ukraine and elsewhere. The heterogeneity of the local epidemics provides insights into the best prevention and treatment strategies to be deployed in low-resource settings.
| S-EPMC6537868 | biostudies-literature
Project description:IntroductionInjection drug use drives HIV epidemics in many low-resource settings, yet many people who inject drugs (PWID) living with HIV are not diagnosed. We assessed the ability of respondent-driven sampling (RDS) - which uses peer network connections - to identify undiagnosed PWID living with HIV compared to a facility-based strategy in India.MethodsIn six Indian cities from 2014 to 2017, integrated care centers (ICCs) provided HIV testing. From 2016 to 2017, RDS samples of PWID in these same cities were conducted. Using biometric matching, characteristics associated with identification by RDS only and both RDS and ICC, compared to ICC only were explored. Undiagnosed individuals tested positive and did not report a prior diagnosis. The number needed to recruit (NNR) (average number recruited to find one undiagnosed PWID living with HIV) and the identification rate (average number undiagnosed PWID identified per week) assessed the efficiency of RDS vs. ICCs.ResultsThere were 10,759 ICC clients and 6012 RDS participants; 40% of RDS participants were also ICC clients resulting in 14,397 unduplicated PWID. PWID identified by RDS vs. ICC only were more likely to be male (adjusted odds ratios [aOR] RDS only: 6.8, both: 2.7) and living with HIV but undiagnosed (aOR RDS only: 2.5, both: 1.5). Overall, the RDS NNR was 11 and the ICC NNR was 26. The RDS identification rate (18.6/week) was faster than the ICC identification rate (2.7/week) overall and in all cities.ConclusionsRDS required screening fewer PWID and more rapidly identified undiagnosed PWID living with HIV as compared to ICCs.
| S-EPMC10330670 | biostudies-literature
Project description:PurposeRespondent-driven sampling (RDS) is a form of peer-based study recruitment and analysis that incorporates features designed to limit and adjust for biases in traditional snowball sampling. It is being widely used in studies of hidden populations. We report an empirical evaluation of RDS's consistency and variability, comparing groups recruited contemporaneously, by identical methods and using identical survey instruments.MethodsWe randomized recruitment chains from the RDS-based 2012 National HIV Behavioral Surveillance survey of injection drug users in the Seattle area into two groups and compared them in terms of sociodemographic characteristics, drug-associated risk behaviors, sexual risk behaviors, human immunodeficiency virus (HIV) status and HIV testing frequency.ResultsThe two groups differed in five of the 18 variables examined (P ≤ .001): race (e.g., 60% white vs. 47%), gender (52% male vs. 67%), area of residence (32% downtown Seattle vs. 44%), an HIV test in the previous 12 months (51% vs. 38%). The difference in serologic HIV status was particularly pronounced (4% positive vs. 18%). In four further randomizations, differences in one to five variables attained this level of significance, although the specific variables involved differed.ConclusionsWe found some material differences between the randomized groups. Although the variability of the present study was less than has been reported in serial RDS surveys, these findings indicate caution in the interpretation of RDS results.
| S-EPMC4252737 | biostudies-literature