Dataset Information

Differences in reporting of analyses in internal company documents versus published trial reports: comparisons in industry-sponsored trials in off-label uses of gabapentin.

ABSTRACT:

Background

Details about the type of analysis (e.g., intent to treat [ITT]) and definitions (i.e., criteria for including participants in the analysis) are necessary for interpreting a clinical trial's findings. Our objective was to compare the description of types of analyses and criteria for including participants in the publication (i.e., what was reported) with descriptions in the corresponding internal company documents (i.e., what was planned and what was done). Trials were for off-label uses of gabapentin sponsored by Pfizer and Parke-Davis, and documents were obtained through litigation.

Methods and findings

For each trial, we compared internal company documents (protocols, statistical analysis plans, and research reports, all unpublished), with publications. One author extracted data and another verified, with a third person verifying discordant items and a sample of the rest. Extracted data included the number of participants randomized and analyzed for efficacy, and types of analyses for efficacy and safety and their definitions (i.e., criteria for including participants in each type of analysis). We identified 21 trials, 11 of which were published randomized controlled trials, and that provided the documents needed for planned comparisons. For three trials, there was disagreement on the number of randomized participants between the research report and publication. Seven types of efficacy analyses were described in the protocols, statistical analysis plans, and publications, including ITT and six others. The protocol or publication described ITT using six different definitions, resulting in frequent disagreements between the two documents (i.e., different numbers of participants were included in the analyses).

Conclusions

Descriptions of analyses conducted did not agree between internal company documents and what was publicly reported. Internal company documents provide extensive documentation of methods planned and used, and trial findings, and should be publicly accessible. Reporting standards for randomized controlled trials should recommend transparent descriptions and definitions of analyses performed and which study participants are excluded.

SUBMITTER: Vedula SS

PROVIDER: S-EPMC3558476 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Differences in reporting of analyses in internal company documents versus published trial reports: comparisons in industry-sponsored trials in off-label uses of gabapentin.

Vedula S Swaroop SS Li Tianjing T Dickersin Kay K

PLoS medicine 20130129 1

<h4>Background</h4>Details about the type of analysis (e.g., intent to treat [ITT]) and definitions (i.e., criteria for including participants in the analysis) are necessary for interpreting a clinical trial's findings. Our objective was to compare the description of types of analyses and criteria for including participants in the publication (i.e., what was reported) with descriptions in the corresponding internal company documents (i.e., what was planned and what was done). Trials were for off ...[more]

PMID: 23382656

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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:To investigate whether adverse effects data for the sponsor's product are presented more favourably in pharmaceutical industry-funded studies than in non-industry-funded studies.We conducted a systematic review of methodological evaluations that had assessed the relationship between industry funding and the reported risk of adverse effects. Searches were undertaken in 10 databases and supplemented with other sources of information such as handsearching, citation searching, checking conference proceedings and discussion with experts. Two reviewers independently screened the records and carried out data extraction for potentially relevant papers. We included studies that compared the results and interpretation of the adverse effects data according to funding source (e.g. adverse effects data in pharmaceutical industry research vs. data from nonprofit organizations, or from one manufacturer vs. another). Methodological evaluations were excluded if categories of funding source were not explicitly specified by the researchers, and if we were uncertain that industry-funded studies were present in the evaluation.The search strategy yielded 4,069 hits, of which six methodological evaluations met our inclusion criteria. One survey of 370 trials covering a wide range of topics found that trials with industry sponsors had more complete reporting of adverse effects compared with non-industry-funded trials, whereas another survey of 504 inhaled corticosteroid studies showed no apparent difference after confounding factors were adjusted for. In contrast, we found evidence from post hoc subgroup analyses involving two products where the likelihood of harm was of a lower magnitude in manufacturer-funded studies compared with nonmanufacturer-funded studies. There is also evidence from four methodological evaluations that authors with industry funding were more likely than authors without pharmaceutical funding to interpret and conclude that a drug was safe, even among studies that did find a statistically significant increase in adverse effects for the sponsored product.Our review indicates that industry funding may not be a major threat to bias in the reporting of the raw adverse effects data. However, we are concerned about potential bias in the interpretation and conclusions of industry-funded authors and studies.

Dataset Information

Differences in reporting of analyses in internal company documents versus published trial reports: comparisons in industry-sponsored trials in off-label uses of gabapentin.

Background

Methods and findings

Conclusions

Publications

Differences in reporting of analyses in internal company documents versus published trial reports: comparisons in industry-sponsored trials in off-label uses of gabapentin.

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