Data sharing: experience of accessing individual patient data from completed randomised controlled trials in vascular and cognitive medicine

Objectives Meta-analysis based on individual patient data (IPD) from randomised trials is superior to using published summary data since it facilitates subgroup and multiple variable analyses. Guidelines and funders expect that researchers share IPD for bona fide analyses, but in practice, this is d...

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Main Authors: Philip M Bath, Alan A Montgomery, Lisa J Woodhouse, Polly Scutt
Format: Article
Language:English
Published: BMJ Publishing Group 2020-09-01
Series:BMJ Open
Online Access:https://bmjopen.bmj.com/content/10/9/e038765.full
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author Philip M Bath
Alan A Montgomery
Lisa J Woodhouse
Polly Scutt
author_facet Philip M Bath
Alan A Montgomery
Lisa J Woodhouse
Polly Scutt
author_sort Philip M Bath
collection DOAJ
description Objectives Meta-analysis based on individual patient data (IPD) from randomised trials is superior to using published summary data since it facilitates subgroup and multiple variable analyses. Guidelines and funders expect that researchers share IPD for bona fide analyses, but in practice, this is done variably. Here, we report the experience of obtaining IPD for two collaborative analysis studies.Setting Two linked studies required IPD from published randomised trials. The leading researchers for eligible trials were approached and asked to share IPD including trial characteristics, patient demographics, baseline clinical data and outcome measures.Participants Participants in eligible randomised controlled trials included patients with or at risk of cognitive decline/vascular events.Primary and secondary outcome measures Numbers (%) of trials where the leading researcher responded favourably/negatively or did not respond. If negative, reasons behind the response were collected. If positive, methods used to share IPD were recorded.Results Across the two studies, 391 completed trials were identified. Email addresses for researchers were found for 313 (80%) of the trials. One hundred and forty-eight (47%) researchers did not respond despite being sent multiple emails. Following contact, positive initial responses were received from 92 researchers, resulting in IPD being shared for 78 trials. Eighty-seven (28%) researchers declined to share data; justifications were recorded. The median time from first request to accessing data in one study was 241 (IQR 383.3) days. IPD sources included: direct from researcher, via academic trial funders repository and a website requiring remote analysis of commercial data. Where data were shared, a variety of methods were used to transfer data.Conclusion Sharing of IPD from trials is desirable and a requirement of many funding bodies. However, accessing IPD faces multiple challenges including refusals to share, delays in access to data and having to perform analyses on a remote website.Trial registration Not applicable.
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spelling doaj-art-5433f4aefade4257a51f9180274b51bf2025-01-09T01:20:08ZengBMJ Publishing GroupBMJ Open2044-60552020-09-0110910.1136/bmjopen-2020-038765Data sharing: experience of accessing individual patient data from completed randomised controlled trials in vascular and cognitive medicinePhilip M Bath0Alan A Montgomery1Lisa J Woodhouse2Polly Scutt31 Stroke, Division of Clinical Neurosciences, University of Nottingham, Nottingham, UKNottingham Clinical Trials Unit, University of Nottingham, Nottingham, Nottinghamshire, UK1 Stroke, Division of Clinical Neurosciences, University of Nottingham, Nottingham, UKStroke Trials Unit, Mental Health and Clinical Neurosciences, University of Nottingham, Nottingham, UKObjectives Meta-analysis based on individual patient data (IPD) from randomised trials is superior to using published summary data since it facilitates subgroup and multiple variable analyses. Guidelines and funders expect that researchers share IPD for bona fide analyses, but in practice, this is done variably. Here, we report the experience of obtaining IPD for two collaborative analysis studies.Setting Two linked studies required IPD from published randomised trials. The leading researchers for eligible trials were approached and asked to share IPD including trial characteristics, patient demographics, baseline clinical data and outcome measures.Participants Participants in eligible randomised controlled trials included patients with or at risk of cognitive decline/vascular events.Primary and secondary outcome measures Numbers (%) of trials where the leading researcher responded favourably/negatively or did not respond. If negative, reasons behind the response were collected. If positive, methods used to share IPD were recorded.Results Across the two studies, 391 completed trials were identified. Email addresses for researchers were found for 313 (80%) of the trials. One hundred and forty-eight (47%) researchers did not respond despite being sent multiple emails. Following contact, positive initial responses were received from 92 researchers, resulting in IPD being shared for 78 trials. Eighty-seven (28%) researchers declined to share data; justifications were recorded. The median time from first request to accessing data in one study was 241 (IQR 383.3) days. IPD sources included: direct from researcher, via academic trial funders repository and a website requiring remote analysis of commercial data. Where data were shared, a variety of methods were used to transfer data.Conclusion Sharing of IPD from trials is desirable and a requirement of many funding bodies. However, accessing IPD faces multiple challenges including refusals to share, delays in access to data and having to perform analyses on a remote website.Trial registration Not applicable.https://bmjopen.bmj.com/content/10/9/e038765.full
spellingShingle Philip M Bath
Alan A Montgomery
Lisa J Woodhouse
Polly Scutt
Data sharing: experience of accessing individual patient data from completed randomised controlled trials in vascular and cognitive medicine
BMJ Open
title Data sharing: experience of accessing individual patient data from completed randomised controlled trials in vascular and cognitive medicine
title_full Data sharing: experience of accessing individual patient data from completed randomised controlled trials in vascular and cognitive medicine
title_fullStr Data sharing: experience of accessing individual patient data from completed randomised controlled trials in vascular and cognitive medicine
title_full_unstemmed Data sharing: experience of accessing individual patient data from completed randomised controlled trials in vascular and cognitive medicine
title_short Data sharing: experience of accessing individual patient data from completed randomised controlled trials in vascular and cognitive medicine
title_sort data sharing experience of accessing individual patient data from completed randomised controlled trials in vascular and cognitive medicine
url https://bmjopen.bmj.com/content/10/9/e038765.full
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