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Comparison of HIV Risk Behaviors Between Clinical Trials and Observational Cohorts in Uganda.

ABSTRACT: Many key populations have high-risk behaviors for HIV infection making them suitable for HIV vaccine efficacy trials. However, these behaviors may change when participants enroll into a trial. We used HIV simulated vaccine efficacy trials (SiVETs) nested within observational cohorts of fisherfolks and female sex workers in Uganda to evaluate this difference. We screened observational cohort participants for enrolment into SiVETs, until 572 were enrolled. Those not enrolled (n?=?953) continued participation in the observational cohorts. We determined risk behaviors at baseline and at 1 year, assigned a numeric score to each behavior and defined composite score as the sum of reported behaviors. We compared changes in scores over 12 months. Both observational cohorts and SiVETs saw a significant decrease in score but greatest in the SiVETs. Investigators recruiting for trials from these populations should consider the likely effect of reduction in risk behaviors on incident HIV infection and trial statistical power.

SUBMITTER: Abaasa A

PROVIDER: S-EPMC7467908 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

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Comparison of HIV Risk Behaviors Between Clinical Trials and Observational Cohorts in Uganda.

Abaasa Andrew A Nash Stephen S Mayanja Yunia Y Price Matt A MA Fast Patricia E PE Kaleebu Pontiano P Todd Jim J

AIDS and behavior 20201001 10

Many key populations have high-risk behaviors for HIV infection making them suitable for HIV vaccine efficacy trials. However, these behaviors may change when participants enroll into a trial. We used HIV simulated vaccine efficacy trials (SiVETs) nested within observational cohorts of fisherfolks and female sex workers in Uganda to evaluate this difference. We screened observational cohort participants for enrolment into SiVETs, until 572 were enrolled. Those not enrolled (n = 953) continued pa ...[more]

PMID: 32277309

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Project description:BackgroundIndividuals at clinical high risk of psychosis (CHR-P) recruited in randomized clinical trials (RCTs) and observational cohorts may display a different enrichment and hence risk of transition to psychosis. No meta-analysis has ever addressed this issue.Methods"Preferred Reporting Items for Systematic reviews and Meta-Analyses" (PRISMA) and "Meta-analysis Of Observational Studies in Epidemiology" (MOOSE)-compliant meta-analysis. PubMed and Web of Science were searched until November 2020 (PROSPERO:CRD42021229223). We included nonoverlapping longitudinal studies (RCTs-control condition and observational cohorts) reporting the transition to psychosis in CHR-P individuals. The primary effect size measure was the cumulative risk of transition at 0.5, 1, and 2 years follow-up in RCTs compared to observational cohorts. Random effects meta-analyses, heterogeneity assessment, quality assessment, and meta-regressions were conducted.ResultsNinety-four independent studies (24 RCTs, 70 observational cohorts) and 9,243 individuals (mean age = 20.1 ± 3.0 years; 43.7% females) were included. The meta-analytical risk of transitioning to psychosis from a CHR-P stage was 0.091 (95% confidence intervals [CI] = 0.068-0.121) at 0.5 years, 0.140 (95% CI = 0.101-0.191) at 1 year and 0.165 (95% CI = 0.097-0.267) at 2 years follow-up in RCTs, and 0.081 (95% CI = 0.067-0.099) at 0.5 years, 0.138 (95% CI = 0.114-0.167) at 1 year, and 0.174 (95% CI = 0.156-0.193) at 2 years follow-up in observational cohorts. There were no between-group differences in transition risks (p > 0.05). The proportion of CHR-P individuals with substance use disorders (excluding alcohol and cannabis) was higher in observational cohorts (16.8, 95% CI = 13.3-21.0%) than in RCTs (3.4, 95% CI = 0.8-12.7%; p = 0.018).ConclusionsThere is no meta-analytic evidence supporting sampling biases in RCTs of CHR-P individuals. Further RCTs are needed to detect effective interventions to prevent psychosis in this at-risk group.

Project description:ObjectiveTo examine concordance between treatment effects in animal experiments and clinical trials. Study design Systematic review.Data sourcesMedline, Embase, SIGLE, NTIS, Science Citation Index, CAB, BIOSIS.Study selectionAnimal studies for interventions with unambiguous evidence of a treatment effect (benefit or harm) in clinical trials: head injury, antifibrinolytics in haemorrhage, thrombolysis in acute ischaemic stroke, tirilazad in acute ischaemic stroke, antenatal corticosteroids to prevent neonatal respiratory distress syndrome, and bisphosphonates to treat osteoporosis. Review methods Data were extracted on study design, allocation concealment, number of randomised animals, type of model, intervention, and outcome.ResultsCorticosteroids did not show any benefit in clinical trials of treatment for head injury but did show a benefit in animal models (pooled odds ratio for adverse functional outcome 0.58, 95% confidence interval 0.41 to 0.83). Antifibrinolytics reduced bleeding in clinical trials but the data were inconclusive in animal models. Thrombolysis improved outcome in patients with ischaemic stroke. In animal models, tissue plasminogen activator reduced infarct volume by 24% (95% confidence interval 20% to 28%) and improved neurobehavioural scores by 23% (17% to 29%). Tirilazad was associated with a worse outcome in patients with ischaemic stroke. In animal models, tirilazad reduced infarct volume by 29% (21% to 37%) and improved neurobehavioural scores by 48% (29% to 67%). Antenatal corticosteroids reduced respiratory distress and mortality in neonates whereas in animal models respiratory distress was reduced but the effect on mortality was inconclusive (odds ratio 4.2, 95% confidence interval 0.85 to 20.9). Bisphosphonates increased bone mineral density in patients with osteoporosis. In animal models the bisphosphonate alendronate increased bone mineral density compared with placebo by 11.0% (95% confidence interval 9.2% to 12.9%) in the combined results for the hip region. The corresponding treatment effect in the lumbar spine was 8.5% (5.8% to 11.2%) and in the combined results for the forearms (baboons only) was 1.7% (-1.4% to 4.7%).ConclusionsDiscordance between animal and human studies may be due to bias or to the failure of animal models to mimic clinical disease adequately.

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Comparison of HIV Risk Behaviors Between Clinical Trials and Observational Cohorts in Uganda.

Publications

Comparison of HIV Risk Behaviors Between Clinical Trials and Observational Cohorts in Uganda.

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