- Title
- Bias and loss to follow-up in cardiovascular randomized trials: a systematic review
- Creator
- Fong, Lucas Chun Wah; Ford, Thomas J.; da Costa, Bruno R.; Jüni, Peter; Berry, Colin
- Relation
- Journal of the American Heart Association Vol. 9, Issue 14, no. e015361
- Publisher Link
- http://dx.doi.org/10.1161/JAHA.119.015361
- Publisher
- Wiley-Blackwell
- Resource Type
- journal article
- Date
- 2020
- Description
- Background: Loss to follow‐up (LTFU) is common in randomized controlled trials. However, its potential impact on primary outcomes from cardiovascular randomized controlled trials is not known. Methods and Results: We conducted a prospective systematic review (PROSPERO: CRD42019121959) for randomized controlled trials published in 8 leading journals over 5 years from January 2014 to December 2018. Extent, reporting, and handling of LTFU data were recorded, and the proportion of a trial's primary outcome results that lose statistical significance was calculated after making plausible assumptions for the intervention and control arms. These assumptions could drive differential treatment effects between the groups considering relative event incidence between LTFU participants and those included in the primary outcome. We identified 117 randomized controlled trials of which 91 (78%) trials reported LTFU, 23 (20%) reported no LTFU, and 3 (3%) trials did not report on whether LTFU occurred. The median percentage of study participants lost to follow‐up was 2% (interquartile range, 0.33%–5.3%). Only 10 trials (9%) had a low cluster of risk factors for impairment in trial quality. The percentage of trials losing statistical significance varied from 2% when the relative event incidence for LTFU between the randomized groups was 1 for the intervention arm and 1.5 for the control arm to 16% when the relative event incidence was 3 for the intervention arm and 1 for the control arm. Conclusions: Almost 1 in 6 (16%) cardiovascular randomized trials published in leading journals may have a change in the primary outcome if plausible assumptions are made about differential event rates of participants lost to follow up. There is scope for improvement arising from LTFU in randomized trials in cardiovascular medicine.
- Subject
- bias; loss to follow-up; outcome; outcome and proess assessment; dropout; randomized controlled trials; relative risk; SDG 7; Sustainable Development Goals
- Identifier
- http://hdl.handle.net/1959.13/1431382
- Identifier
- uon:38955
- Identifier
- ISSN:2047-9980
- Rights
- © 2020 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
- Language
- eng
- Full Text
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