Retrieval barriers in individual participant data reviews with network meta-analysis

Abstract

ObjectivesIndividual participant data (IPD) from randomised controlled trials (RCTs) can be used in network meta-analysis (NMA) to underpin patient care and are the best analyses to support the development of guidelines about the use of healthcare interventions for a specific condition. However, barriers to IPD retrieval pose a major threat. The aim of this study was to present barriers we encountered during retrieval of IPD from RCTs in two published systematic reviews with IPD-NMA.MethodsWe evaluated retrieval of IPD from RCTs for IPD-NMA in Alzheimer’s dementia and type 1 diabetes. We requested IPD from authors, industry sponsors and data repositories, and recorded IPD retrieval, reasons for IPD unavailability, and retrieval challenges.ResultsIn total, we identified 108 RCTs: 78 industry sponsored, 11 publicly sponsored and 19 with no funding information. After failing to obtain IPD from any trial authors, we requested it from industry sponsors. Seven of the 17 industry sponsors shared IPD for 12 950 participants (59%) through proprietary-specific data sharing platforms from 26 RCTs (33%). We found that lack of RCT identifiers (eg, National Clinical Trial number) and unclear data ownership were major challenges in IPD retrieval. Incomplete information in retrieved datasets was another important problem that led to exclusion of RCTs from the NMA. There were also practical challenges in obtaining IPD from or analysing it within platforms, and additional costs were incurred in accessing IPD this way.ConclusionsWe found no clear evidence of retrieval bias (where IPD availability was linked to trial findings) in either IPD-NMA, but because retrieval bias could impact NMA findings, subsequent decision-making and guideline development, this should be considered when assessing risk of bias in IPD syntheses.

Heterogeneity and Utility of Pharmaceutical Company Sharing of Individual-Participant Data Packages

“…Recent research evaluated the ability to retrieve IPD from a sample of clinical trials for Alzheimer disease and diabetes medications . The sample included both industry- and non–industry-sponsored trials, with no restrictions on trial age .…”

“…Their sample of 108 trials included 11 publicly funded trials and 19 trials for which the authors could not establish funding information. The IPD could not be accessed from any of these 30 randomized clinical trials . For the remaining 78 industry-sponsored trials, IPD could only be accessed from 26 (33%) .…”

“…The IPD could not be accessed from any of these 30 randomized clinical trials . For the remaining 78 industry-sponsored trials, IPD could only be accessed from 26 (33%) . Of the 52 industry-sponsored trials where IPD could not be accessed, 40 (77%) were noted as either too old with IPD destroyed, or there was difficulty establishing IPD ownership .…”

“…At present, accessing high-quality IPD from non–industry-sponsored trials is extremely difficult and often impossible . As such, this study focused on the acquisition and utility of IPD packages from industry-sponsored oncology trials for recently approved anticancer medicines.…”

“…Sharing IPD allows verification of results, generation of hypotheses, and the undertaking of analyses that can inform clinical practice and improve trial designs . To achieve these outcomes, the data sharing ecosystem must operate efficiently and have redaction and anonymization processes that maintain IPD usability as well as preserve participant confidentiality . Toward this end, substantial efforts have gone into developing processes to facilitate data requests and infrastructures to anonymize and protect IPD .…”