Short email with attachment versus long email without attachment when contacting authors to request unpublished data for a systematic review: a nested randomised trial

Godolphin, Peter J.; Bath, Philip M.; Montgomery, Alan A.

Abstract

Objective: Systematic reviews often rely on the acquisition of unpublished analyses or data. We carried out a nested randomised trial comparing two different approaches for contacting authors to request additional data for a systematic review.
Participants: Participants were authors of published reports of prevention or treatment trials in stroke in which there was central adjudication of events. A primary and secondary research active author were selected as contacts for each trial.
Interventions: Authors were randomised to be sent either a short email with a protocol of the systematic review attached (“Short”), or a longer email that contained detailed information and without the protocol attached (“Long”). A maximum of two emails were sent to each author to obtain a response. The unit of analysis was trial, accounting for clustering by author.
Primary and secondary outcome measures: The primary outcome was whether a response was received from authors. Secondary outcomes included time to response, number of reminders needed before a response was received and whether authors agreed to collaborate.
Results: 88 trials with 76 primary authors were identified in the systematic review, and of these, 36 authors were randomised to Short [trials=45], and 40 to Long [trials=43]. Responses were received for 69 trials. There was no evidence of a difference in response rate between trial arms (Short vs Long, odds ratio 1.10, 95% C.I: [0.36, 3.33]). There was no evidence of a difference in time to response between trial arms (Short vs Long, hazard ratio 0.91, 95% C.I: [0.55, 1.51]). In total, 27% of authors responded within a day and 22% of authors never responded.
Conclusions: There was no evidence to suggest that email format had an impact on the number of responses received when acquiring data for a systematic review involving stroke trials, or the time taken to receive these responses.

• Journal Article Type: Article
• Acceptance Date: Nov 29, 2018
• Online Publication Date: Jan 30, 2019
• Publication Date: 2019-05
• Deposit Date: Feb 15, 2019
• Publicly Available Date: Feb 15, 2019
• Journal: BMJ Open
• Electronic ISSN: 2044-6055
• Publisher: BMJ Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 1
• Article Number: e25273
• DOI: https://doi.org/10.1136/bmjopen-2018-025273
• Public URL: https://nottingham-repository.worktribe.com/output/1472559
• Publisher URL: https://bmjopen.bmj.com/content/9/1/e025273