Dataset Information

Assessment of Language and Indexing Biases Among Chinese-Sponsored Randomized Clinical Trials.

ABSTRACT: Importance:Language and indexing biases may exist among Chinese-sponsored randomized clinical trials (CS-RCTs). Such biases may threaten the validity of systematic reviews. Objective:To evaluate the existence of language and indexing biases among CS-RCTs on drug interventions. Design, Setting, and Participants:In this retrospective cohort study, eligible CS-RCTs were retrieved from trial registries, and bibliographic databases were searched to determine their publication status. Eligible CS-RCTs were for drug interventions conducted from January 1, 2008, to December 31, 2014. The search and analysis were conducted from March 1 to August 31, 2019. Primary trial registries were recognized by the World Health Organization and the Drug Clinical Trial Registry Platform sponsored by the China Food and Drug Administration. Exposures:Individual CS-RCTs with positive vs negative results (positive vs negative CS-RCTs). Main Outcomes and Measures:For assessing language bias, the main outcome was the language of the journal in which CS-RCTs were published (English vs Chinese). For indexing bias, the main outcome was the language of the bibliographic database where the CS-RCTs were indexed (English vs Chinese). Results:The search identified 891 eligible CS-RCTs. Four hundred seventy CS-RCTs were published by August 31, 2019, of which 368 (78.3%) were published in English. Among CS-RCTs registered in the Chinese Clinical Trial Registry (ChiCTR), positive CS-RCTs were 3.92 (95% CI, 2.20-7.00) times more likely to be published in English than negative CS-RCTs; among CS-RCTs in English-language registries, positive CS-RCTs were 3.22 (95% CI, 1.34-7.78) times more likely to be published in English than negative CS-RCTs. These findings suggest the existence of language bias. Among CS-RCTs registered in ChiCTR, positive CS-RCTs were 2.89 (95% CI, 1.55-5.40) times more likely to be indexed in English bibliographic databases than negative CS-RCTs; among CS-RCTs in English-language registries, positive CS-RCTs were 2.19 (95% CI, 0.82-5.82) times more likely to be indexed in English bibliographic databases than negative CS-RCTs. These findings support the existence of indexing bias. Conclusions and Relevance:This study suggests the existence of language and indexing biases among registered CS-RCTs on drug interventions. These biases may distort evidence synthesis toward more positive results of drug interventions.

SUBMITTER: Jia Y

PROVIDER: S-EPMC7256669 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature

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Assessment of Language and Indexing Biases Among Chinese-Sponsored Randomized Clinical Trials.

Jia Yuanxi Y Huang Doudou D Wen Jiajun J Wang Yehua Y Rosman Lori L Chen Qingkun Q Robinson Karen A KA Gagnier Joel J JJ Ehrhardt Stephan S Celentano David D DD

JAMA network open 20200501 5

<h4>Importance</h4>Language and indexing biases may exist among Chinese-sponsored randomized clinical trials (CS-RCTs). Such biases may threaten the validity of systematic reviews.<h4>Objective</h4>To evaluate the existence of language and indexing biases among CS-RCTs on drug interventions.<h4>Design, setting, and participants</h4>In this retrospective cohort study, eligible CS-RCTs were retrieved from trial registries, and bibliographic databases were searched to determine their publication st ...[more]

PMID: 32463469

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Project description:ImportanceDuplicate publications of randomized clinical trials are prevalent in the health-related literature. To date, few studies have assessed the interaction between duplicate publication and the language of the original publication.ObjectiveTo assess the existence of duplicate publication and the extent to which duplicate publication is associated with the language of the original publication.Design, setting, and participantsIn this retrospective cohort study, eligible randomized clinical trials were retrieved from trial registries, and bibliographic databases were searched to determine their publication status. Eligible randomized clinical trials were for drug interventions from January 1, 2008, to December 31, 2014. The search and analysis were conducted from March 1 to August 31, 2019. The trial registries were either primary registries recognized by the World Health Organization or the Drug Clinical Trial Registry Platform sponsored by the China Food and Drug Administration.ExposuresIndividual randomized clinical trials with positive vs negative results.Main outcomes and measuresJournal articles were classified as main articles (determined by largest sample size and longest follow-up among all journal articles derived from that randomized clinical trial) and duplicates. The duplicates were classified into 4 types: (1) unreferenced subgroup analysis (article did not disclose itself as a subgroup analysis or reference its main article); (2) unreferenced republication (article did not disclose itself as a replicate of the main article or reference it); (3) unreferenced interim analysis (article did not disclose itself as an interim analysis or reference its main article); and (4) partial duplicate (article did not disclose its sharing a subset of participants with other articles or reference them).ResultsAmong 470 randomized clinical trials published by August 2019 as journal articles, 55 (11.7%) had 75 duplicates, of which 53 (70.7%) were cross-language duplicates. Of the 75 duplicates, 33 (44.0%) were unreferenced republications, 25 (33.3%) unreferenced subgroup analyses, 15 (20.0%) unreferenced interim analyses, and 2 (2.7%) partial duplicates. When the main article of a randomized clinical trial was published in Chinese, those with positive findings were 2.48 (95% CI, 1.08-5.71) times more likely to have subsequent duplicate publication than those with negative findings.Conclusions and relevanceIn this study, most duplicates were cross-language duplicates and the most common type was unreferenced republication of the main article. Duplicate publication bias exists when the main articles of randomized clinical trials were published in Chinese, potentially misleading readers and compromising journals and evidence synthesis.

Project description:BackgroundHealthcare decisions are ideally based on clinical trial results, published in study registries, as journal articles or summarized in secondary research articles. In this research project, we investigated the impact of academically and commercially sponsored clinical trials on medical practice by measuring the proportion of trials published and cited by systematic reviews and clinical guidelines.MethodsWe examined 691 multicenter, randomized controlled trials that started in 2005 or later and were completed by the end of 2016. To determine whether sponsorship/funding and place of conduct influence a trial's impact, we created four sub-cohorts of investigator initiated trials (IITs) and industry sponsored trials (ISTs): 120 IITs and 171 ISTs with German contribution compared to 200 IITs and 200 ISTs without German contribution. We balanced the groups for study phase and place of conduct. German IITs were funded by the German Research Foundation (DFG), the Federal Ministry of Education and Research (BMBF), or by another non-commercial research organization. All other trials were drawn from the German Clinical Trials Register or ClinicalTrials.gov. We investigated, to what extent study characteristics were associated with publication and impact using multivariable logistic regressions.ResultsFor 80% of the 691 trials, results were published as result articles in a medical journal and/or study registry, 52% were cited by a systematic review, and 26% reached impact in a clinical guideline. Drug trials and larger trials were associated with a higher probability to be published and to have an impact than non-drug trials and smaller trials. Results of IITs were more often published as a journal article while results of ISTs were more often published in study registries. International ISTs less often gained impact by inclusion in systematic reviews or guidelines than IITs.ConclusionAn encouraging high proportion of the clinical trials were published, and a considerable proportion gained impact on clinical practice. However, there is still room for improvement. For publishing study results, study registries have become an alternative or complement to journal articles, especially for ISTs. IITs funded by governmental bodies in Germany reached an impact that is comparable to international IITs and ISTs.

Project description:BackgroundMapping the international landscape of clinical trials may inform global health research governance, but no large-scale data are available. Industry or non-industry sponsorship may have a major influence in this mapping. We aimed to map the global landscape of industry- and non-industry-sponsored clinical trials and its evolution over time.MethodsWe analyzed clinical trials initiated between 2006 and 2013 and registered in the WHO International Clinical Trials Registry Platform (ICTRP). We mapped single-country and international trials by World Bank's income groups and by sponsorship (industry- vs. non- industry), including its evolution over time from 2006 to 2012. We identified clusters of countries that collaborated significantly more than expected in industry- and non-industry-sponsored international trials.Results119,679 clinical trials conducted in 177 countries were analysed. The median number of trials per million inhabitants in high-income countries was 100 times that in low-income countries (116.0 vs. 1.1). Industry sponsors were involved in three times more trials per million inhabitants than non-industry sponsors in high-income countries (75.0 vs. 24.5) and in ten times fewer trials in low- income countries (0.08 vs. 1.08). Among industry- and non-industry-sponsored trials, 30.3% and 3.2% were international, respectively. In the industry-sponsored network of collaboration, Eastern European and South American countries collaborated more than expected; in the non-industry-sponsored network, collaboration among Scandinavian countries was overrepresented. Industry-sponsored international trials became more inter-continental with time between 2006 and 2012 (from 54.8% to 67.3%) as compared with non-industry-sponsored trials (from 42.4% to 37.2%).ConclusionsBased on trials registered in the WHO ICTRP we documented a substantial gap between the globalization of industry- and non-industry-sponsored clinical research. Only 3% of academic trials but 30% of industry trials are international. The latter appeared to be conducted in preferentially selected countries.

Project description:Purpose To identify factors related to who undergoes a prostate biopsy in a screened population and to estimate the impact of biopsy verification on risk factor-prostate cancer associations. Patients and Methods Men who were screened regularly from the placebo arms of two large prostate cancer prevention trials (Prostate Cancer Prevention Trial [PCPT] and Selenium and Vitamin E Cancer Prevention Trial [SELECT]) were examined to define incident prostate cancer cohorts. Because PCPT had an end-of-study biopsy, prostate cancer cases were categorized by a preceding prostate-specific antigen/digital rectal examination prompt (yes/no) and noncases by biopsy-proven negative status (yes v no). We estimated the association of risk factors (age, ethnicity, family history, body mass index, medication use) with prostate cancer and quantified differences in risk associations across cohorts. Results Men 60 to 69 years of age, those with benign prostatic hyperplasia, and those with a family history of prostate cancer were more likely, and those with a higher body mass index (≥ 25), diabetes, or a smoking history were less likely, to undergo biopsy, adjusting for age and longitudinal prostate-specific antigen and digital rectal examination. Medication use, education, and marital status also influenced who underwent biopsy. Some risk factor estimates for prostate cancer varied substantially across cohorts. Black ( v other ethnicities) had odds ratios (ORs) that varied from 1.20 for SELECT (community screening standards, epidemiologic-like cohort) to 1.83 for PCPT (end-of-study biopsy supplemented with imputed end points). Statin use in SELECT provided an OR of 0.65 and statin use in in PCPT provided an OR of 0.99, a relative difference of 34%. Conclusion Among screened men enrolled in prostate cancer prevention trials, differences in risk factor estimates for prostate cancer likely underestimate the magnitude of bias found in other cohorts with varying screening and biopsy recommendations and acceptance. Risk factors for prostate cancer derived from epidemiologic studies not only may be erroneous but may lead to misdirected research efforts.

Project description:BackgroundDemographic diversity among clinical trials is required for representing the real-world populations intended for treatment and disease prevention. Moreover, genetic and environmental differences between ethnic and racial groups necessitate appropriately powered trials for relevant subgroups. We investigate the racial and ethnic demographic diversity of US-based participants in GSK-sponsored interventional trials. We also assess the evaluation of demographic diversity against US Census and epidemiologic data.MethodsGSK-sponsored interventional phase I-IV clinical trials conducted from 2002 to 2019 across three areas were analyzed: pharmaceutical (includes therapeutic medicines except for vaccines and human immunodeficiency virus (HIV)), vaccine (includes prophylactic and therapeutic vaccines), and ViiV (includes HIV therapies). A total of 1005 global trials encompassing 460,707 global participants were identified, of which 495 had US-based sites with a total of 108,261 (23.5% of global) US participants (pharmaceutical, n = 357 trials; vaccine, n = 45 trials; and ViiV, n = 93 trials). We evaluated how GSK US-based trial recruitment compares with US Census (in line with previously published studies from other groups) and with epidemiologic data.ResultsGSK participant data for race and ethnicity combined across areas were generally similar to US Census levels (e.g. GSK versus census: White, 76.5% versus 76.3%; Black or African American, 15.1% versus 13.4%; Asian, 1.8% versus 5.9%; Hispanic or Latino, 14.0% versus 18.5%; Non-Hispanic White, 63.5% versus 60.1%). However, this was not the case for the individual pharmaceutical, vaccine, and ViiV data sets; least represented groups were Asian individuals for pharmaceutical and ViiV trials and American Indian or Alaskan Native individuals for vaccine trials (6.2%, 11.8%, and 11.1% of trials met/exceeded census level representation, respectively). The percentage of trials reaching/exceeding census levels also varied per trial phase for race and ethnicity. Furthermore, disparities in the percentage of trials reaching/exceeding census levels versus epidemiology-based prevalence levels have revealed opportunities to improve industry success metrics; in HIV trials, the proportion of Black or African American individuals (35.1%) exceeded census (13.4%) but not epidemiologic levels (55.3%).ConclusionFurther work is required to achieve demographic diversity across clinical trials. We conclude that US Census data are an inappropriate universal benchmark. A shift to epidemiology benchmarking will enable the consideration of global participants into US analyses for highly intrinsic (i.e. influenced by ancestry) diseases and more firm requirements for US-based participants into US analyses for extrinsic (i.e. influenced by location or culture) diseases. Benchmarking in line with epidemiologic data will allow us to set better trial enrollment goals, with the aim of conducting more demographically balanced, diverse, and representative clinical trials and enabling a better understanding of drug safety and efficacy per demographic group.

Dataset Information

Assessment of Language and Indexing Biases Among Chinese-Sponsored Randomized Clinical Trials.

Publications

Assessment of Language and Indexing Biases Among Chinese-Sponsored Randomized Clinical Trials.

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