Dataset Information

Age biases in a large HIV and sexual behaviour-related internet survey among MSM.

ABSTRACT:

Background

Behavioural data from MSM are usually collected in non-representative convenience samples, increasingly on the internet. Epidemiological data from such samples might be useful for comparisons between countries, but are subject to unknown participation biases.

Methods

Self-reported HIV diagnoses from participants of the European MSM Internet Survey (EMIS) living in the Czech Republic, Germany, The Netherlands, Portugal, Sweden and the United Kingdom were compared with surveillance data, for both the overall diagnosed prevalence and for new diagnoses made in 2009. Country level prevalence and new diagnoses rates per 100 MSM were calculated based on an assumed MSM population size of 3% of the adult male population. Survey-surveillance discrepancies (SSD) for survey participation, diagnosed HIV prevalence and new HIV diagnoses were determined as ratios of proportions. Results are calculated and presented by 5-year age groups for MSM aged 15-64.

Results

Surveillance derived estimates of diagnosed HIV prevalence among MSM aged 15-64 ranged from 0.63% in the Czech Republic to 4.93% in The Netherlands. New HIV diagnoses rates ranged between 0.10 per 100 MSM in the Czech Republic and 0.48 per 100 in The Netherlands. Self-reported rates from EMIS were consistently higher, with prevalence ranging from 2.68% in the Czech Republic to 12.72% in The Netherlands, and new HIV diagnoses rates from 0.36 per 100 in Sweden to 1.44 per 100 in The Netherlands. Across age groups, the survey surveillance discrepancies (SSD) for new HIV diagnoses were between 1.93 in UK and 5.95 in the Czech Republic, and for diagnosed prevalence between 1.80 in Germany and 4.26 in the Czech Republic.Internet samples of MSM were skewed towards younger age groups when compared to an age distribution of the general adult male population. Survey-surveillance discrepancies (SSD) for EMIS participation were inverse u-shaped across the age range. The two HIV-related SSD were u- or j-shaped with higher values for the very young and for older MSM. The highest discrepancies between survey and surveillance data regarding HIV-prevalence were observed in the oldest age group in Sweden and the youngest age group in Portugal.

Conclusion

Internet samples are biased towards a lower median age because younger men are over-represented on MSM dating websites and therefore may be more likely to be recruited into surveys. Men diagnosed with HIV were over-represented in the internet survey, and increasingly so in the older age groups. A similar effect was observed in the age groups younger than 25 years. Self-reported peak prevalence and peak HIV diagnoses rates are often shifted to higher age groups in internet samples compared to surveillance data. Adjustment for age-effects on online accessibility should be considered when linking data from internet surveys with surveillance data.

SUBMITTER: Marcus U

PROVIDER: S-EPMC3847490 | biostudies-literature | 2013 Sep

REPOSITORIES: biostudies-literature

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Publications

Age biases in a large HIV and sexual behaviour-related internet survey among MSM.

Marcus Ulrich U Hickson Ford F Weatherburn Peter P Schmidt Axel J AJ

BMC public health 20130910

<h4>Background</h4>Behavioural data from MSM are usually collected in non-representative convenience samples, increasingly on the internet. Epidemiological data from such samples might be useful for comparisons between countries, but are subject to unknown participation biases.<h4>Methods</h4>Self-reported HIV diagnoses from participants of the European MSM Internet Survey (EMIS) living in the Czech Republic, Germany, The Netherlands, Portugal, Sweden and the United Kingdom were compared with su ...[more]

PMID: 24020518

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Project description:BackgroundCountry level comparisons of HIV prevalence among men having sex with men (MSM) is challenging for a variety of reasons, including differences in the definition and measurement of the denominator group, recruitment strategies and the HIV detection methods. To assess their comparability, self-reported data on HIV diagnoses in a 2010 pan-European MSM internet survey (EMIS) were compared with pre-existing estimates of HIV prevalence in MSM from a variety of European countries.MethodsThe first pan-European survey of MSM recruited more than 180,000 men from 38 countries across Europe and included questions on the year and result of last HIV test. HIV prevalence as measured in EMIS was compared with national estimates of HIV prevalence based on studies using biological measurements or modelling approaches to explore the degree of agreement between different methods. Existing estimates were taken from Dublin Declaration Monitoring Reports or UNAIDS country fact sheets, and were verified by contacting the nominated contact points for HIV surveillance in EU/EEA countries.ResultsThe EMIS self-reported measurements of HIV prevalence were strongly correlated with existing estimates based on biological measurement and modelling studies using surveillance data (R(2)=0.70 resp. 0.72). In most countries HIV positive MSM appeared disproportionately likely to participate in EMIS, and prevalences as measured in EMIS are approximately twice the estimates based on existing estimates.ConclusionsComparison of diagnosed HIV prevalence as measured in EMIS with pre-existing estimates based on biological measurements using varied sampling frames (e.g. Respondent Driven Sampling, Time and Location Sampling) demonstrates a high correlation and suggests similar selection biases from both types of studies. For comparison with modelled estimates the self-selection bias of the Internet survey with increased participation of men diagnosed with HIV has to be taken into account. For most countries self-reported EMIS prevalence is higher than measured prevalence, which is likely due to a combination of different time points of measurement, measurement errors for small sample sizes, different sampling methods, and an indicator-inherent overestimate of prevalence among the untested fraction of MSM.

Project description:BackgroundComparison of rates of newly diagnosed HIV infections among MSM across countries is challenging for a variety of reasons, including the unknown size of MSM populations. In this paper we propose a method of triangulating surveillance data with data collected in a pan-European MSM Internet Survey (EMIS) to estimate the sizes of the national MSM populations and the rates at which HIV is being diagnosed amongst them by calculating survey-surveillance discrepancies (SSD) as a measure of selection biases of survey participants.MethodsIn 2010, the first EMIS collected self-reported data on HIV diagnoses among more than 180,000 MSM in 38 countries of Europe. These data were compared with data from national HIV surveillance systems to explore possible sampling and reporting biases in the two approaches. The Survey-Surveillance Discrepancy (SSD) represents the ratio of survey members diagnosed in 2009 (HIVsvy) to total survey members (Nsvy), divided by the ratio of surveillance reports of diagnoses in 2009 (HIVpop) to the estimated total MSM population (Npop). As differences in household internet access may be a key component of survey selection biases, we analysed the relationship between household internet access and SSD in countries conducting consecutive MSM internet surveys at different time points with increasing levels of internet access. The empirically defined SSD was used to calculate the respective MSM population sizes (Npop), using the formula Npop = HIVpop*Nsvy*SSD/HIVsvy.ResultsSurvey-surveillance discrepancies for consecutive MSM internet surveys between 2003 and 2010 with different levels of household internet access were best described by a potential equation, with high SSD at low internet access, declining to a level around 2 with broad access. The lowest SSD was calculated for the Netherlands with 1.8, the highest for Moldova with 9.0. Taking the best available estimate for surveillance reports of HIV diagnoses among MSM in 2009 (HIVpop), the relative MSM population sizes were between 0.03% and 5.6% of the adult male population aged 15-64. The correlation between recently diagnosed (2009) HIV in EMIS participants and HIV diagnosed among MSM in 2009 as reported in the national surveillance systems was very high (R(2) = 0.88) when using the calculated MSM population size.ConclusionsNpop and HIVpop were unreliably low for several countries. We discuss and identify possible measurement errors for countries with calculated MSM population sizes above 3% and below 1% of the adult male population. In most cases the number of new HIV diagnoses in MSM in the surveillance system appears too low. In some cases, measurement errors may be due to small EMIS sample sizes. It must be assumed that the SSD is modified by country-specific factors.Comparison of community-based survey data with surveillance data suggests only minor sampling biases in the former that--except for a few countries--do not seriously distort inter-country comparability, despite large variations in participation rates across countries. Internet surveys are useful complements to national surveillance systems, highlighting deficiencies and allowing estimates of the range of newly diagnosed infections among MSM in countries where surveillance systems fail to accurately provide such data.

Project description:Regular HIV testing enables early identification and treatment of HIV among at-risk men who have sex with men (MSM). Characterizing HIV testing needs for Internet-using MSM informs development of Internet-facilitated testing interventions. In this systematic review we analyze HIV testing patterns among Internet-using MSM in the United States who report, through participation in an online study or survey, their HIV status as negative or unknown and identify demographic or behavioral risk factors associated with testing. We systematically searched multiple electronic databases for relevant English-language articles published between January 1, 2005 and December 16, 2014. Using meta-analysis, we summarized the proportion of Internet-using MSM who had ever tested for HIV and the proportion who tested in the 12 months preceding participation in the online study or survey. We also identified factors predictive of these outcomes using meta-regression and narrative synthesis. Thirty-two studies that enrolled 83,186 MSM met our inclusion criteria. Among the studies reporting data for each outcome, 85 % (95 % CI 82-87 %) of participants had ever tested, and 58 % (95 % CI 53-63 %) had tested in the year preceding enrollment in the study, among those for whom those data were reported. Age over 30 years, at least a college education, use of drugs, and self-identification as being homosexual or gay were associated with ever having tested for HIV. A large majority of Internet-using MSM indicated they had been tested for HIV at some point in the past. A smaller proportion-but still a majority-reported they had been tested within the year preceding study or survey participation. MSM who self-identify as heterosexual or bisexual, are younger, or who use drugs (including non-injection drugs) may be less likely to have ever tested for HIV. The overall findings of our systematic review are encouraging; however, a subpopulation of MSM may benefit from targeted outreach. These findings indicate unmet needs for HIV testing among Internet-using MSM and identify subpopulations that might benefit from targeted outreach, such as provision of HIV self-testing kits.

Project description:BackgroundSwingers, heterosexuals who, as couples, practice mate swapping or group sex with other couples or heterosexual singles, are at risk for sexually transmitted infections (STIs). Therefore, the aim of this study was to assess changes in sexual behaviour and STI testing behaviour, as well as predictors of STI testing.MethodsTwo cross-sectional studies were performed, using the same internet survey in 2011 and 2018. For trend analysis, sexual behaviour and STI testing behaviour were used. Socio-demographics, swinger characteristics, sexual behaviour, and psycho-social variables were used to assess predictors of STI testing in the past year, using multivariable regression analysis.ResultsA total of 1173 participants completed the survey in 2011, and 1005 in 2018. Condom use decreased for vaginal (73% vs. 60%), oral (5% vs. 2%), and anal sex (85% vs. 75%). STI positivity was reported in 23% and 30% of the participants, respectively, although testing for STI was comparable between both years (~65%). The following predictors of STI testing were significant: being female (OR = 1.9, 95%CI: 1.2-2.9), having a high swinging frequency (>12 times a year, OR = 3.7, 95%CI: 1.9-7.3), swinging at home (OR = 1.6, 95%CI: 1.0-2.7), receiving a partner notification (OR = 1.7, 95%CI: 1.2-2.6), considering STI testing important (OR = 4.3, 95%CI: 2.2-8.5), experiencing no pressure from a partner to test (OR = 0.6, 95%CI: 0.3-0.9), partners test for STI regularly (OR = 10.0, 95%CI: 6.2-15.9), perceiving STI testing as an obligation (OR = 2.1, 95%CI: 1.3-3.5), experiencing no barriers such as being afraid of testing (OR = 1.9, 95%CI: 1.2-3.1), limited opening hours (OR = 1.6, 95%CI: 1.0-2.4), and forgetting to plan appointments (OR = 3.0, 95%CI: 2.0-4.6).ConclusionsSwingers exhibit self-selection for STI testing based on their sexual behaviour. However, STI prevention efforts are still important considering the increasing numbers of reported STIs, the decreased use of condom use, and the one-third of swingers who were not tested in the previous year.

Project description:Transmission of multiple founder variants has been associated with faster HIV disease progression. Many studies have attempted to determine the number of founder variants, mainly by analysis of sequence diversity and/or tree topology from acutely HIV-infected individuals. We hypothesized that adding sequence data collected from source partners might improve resolution and characterization of transmission events. Blood plasma samples were collected from both the source and recipient in thirty epidemiologically- and phylogenetically linked transmission pairs. All were men who have sex with men, sampled on average 70 days (range 11-170) after the recipient's estimated date of infection. Next generation sequencing (454 FLX, Roche) of HIV-1 env (C2-V3) was performed for all samples. Inspection of sequence alignments, highlighter plots, phylogenetic tree topologies and sequence diversity were used to determine the multiplicity of founder viruses with and without the inclusion of source data. Using only recipient sequence data, we were able to resolve multiplicity in twenty-six of the thirty transmission pairs (87 percent). Among them, five presented with a high viral diversity at baseline (>0.10 subst/site), consistent with multiple founders. By incorporating sequence data collected from the source partner, we were able to characterize all thirty transmission pairs. Overall, sixteen transmission events (53.3 percent) involved multiple founders. Results obtained by combining sequence data from recipient and source were congruent for nineteen of the twenty-six (73 percent) cases where conclusions were made using only recipient sequence data. The multiplicity of founders was associated with significantly higher HIV RNA levels (P = 0.04). To further evaluate the transmission bottleneck, we focused on single founder transmissions (fourteen of the thirty), and identified four recipients (28.6 percent) that had founder variants that were inferred to arise from minority viral populations in the source. These source clades ranged from 1.0 to 5.4 percent of the sampled population. Incorporating sequence data from the source increased of the ability to determine the multiplicity of founder variants, reduced misclassification, and allowed us to infer the transmission of minority variants.

Dataset Information

Age biases in a large HIV and sexual behaviour-related internet survey among MSM.

Background

Methods

Results

Conclusion

Publications

Age biases in a large HIV and sexual behaviour-related internet survey among MSM.

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