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. 2023 Sep 5;6(9):e2336023.
doi: 10.1001/jamanetworkopen.2023.36023.

Reporting of Observational Studies Explicitly Aiming to Emulate Randomized Trials: A Systematic Review

Harrison J Hansford  1   2 , Aidan G Cashin  1   2 , Matthew D Jones  1   2 , Sonja A Swanson  3   4   5 , Nazrul Islam  6   7 , Susan R G Douglas  1 , Rodrigo R N Rizzo  1   2 , Jack J Devonshire  2 , Sam A Williams  2 , Issa J Dahabreh  4   5   8 , Barbra A Dickerman  4   5 , Matthias Egger  9   10   11 , Xabier Garcia-Albeniz  5   12 , Robert M Golub  13 , Sara Lodi  4   14 , Margarita Moreno-Betancur  15   16 , Sallie-Anne Pearson  17 , Sebastian Schneeweiss  18 , Jonathan A C Sterne  19   20   21 , Melissa K Sharp  22 , Elizabeth A Stuart  23 , Miguel A Hernán  4   5   8 , Hopin Lee  24 , James H McAuley  1   2
Affiliations

Reporting of Observational Studies Explicitly Aiming to Emulate Randomized Trials: A Systematic Review

Harrison J Hansford et al. JAMA Netw Open. .

Abstract

Importance: Observational (nonexperimental) studies that aim to emulate a randomized trial (ie, the target trial) are increasingly informing medical and policy decision-making, but it is unclear how these studies are reported in the literature. Consistent reporting is essential for quality appraisal, evidence synthesis, and translation of evidence to policy and practice.

Objective: To assess the reporting of observational studies that explicitly aimed to emulate a target trial.

Evidence review: We searched Medline, Embase, PsycINFO, and Web of Science for observational studies published between March 2012 and October 2022 that explicitly aimed to emulate a target trial of a health or medical intervention. Two reviewers double-screened and -extracted data on study characteristics, key predefined components of the target trial protocol and its emulation (eligibility criteria, treatment strategies, treatment assignment, outcome[s], follow-up, causal contrast[s], and analysis plan), and other items related to the target trial emulation.

Findings: A total of 200 studies that explicitly aimed to emulate a target trial were included. These studies included 26 subfields of medicine, and 168 (84%) were published from January 2020 to October 2022. The aim to emulate a target trial was explicit in 70 study titles (35%). Forty-three studies (22%) reported use of a published reporting guideline (eg, Strengthening the Reporting of Observational Studies in Epidemiology). Eighty-five studies (43%) did not describe all key items of how the target trial was emulated and 113 (57%) did not describe the protocol of the target trial and its emulation.

Conclusion and relevance: In this systematic review of 200 studies that explicitly aimed to emulate a target trial, reporting of how the target trial was emulated was inconsistent. A reporting guideline for studies explicitly aiming to emulate a target trial may improve the reporting of the target trial protocols and other aspects of these emulation attempts.

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Conflict of interest statement

Conflict of Interest Disclosures: Mr Hansford reported receiving grants from National Health and Medical Research Council (NHMRC) and Neuroscience Research Australia during the conduct of the study. Dr Dahabreh reported receiving grants to the institution from Sanofi and consulting fees from Moderna outside the submitted work. Dr Dickerman reported receiving grants from the National Institutes of Health (NIH) during the conduct of the study. Prof Egger reported receiving grants from Swiss National Science Foundation during the conduct of the study. Dr Garcia-Albeniz reported being employed by RTI Health Solutions. Dr Schneeweiss reported receiving consulting fees from Aetion, Inc, and grants from UCB Pharma, Takeda, and Boehringer Ingelheim outside the submitted work. Dr Stuart reported receiving grants from the NIH during the conduct of the study. Dr Hernán reported receiving grants from NIH during the conduct of the study and receiving personal fees from ProPublica, Cytel, and ADIA Lab outside the submitted work. No other disclosures were reported.

Figures

Figure 1.
Figure 1.. Study Flow Diagram
Figure 2.
Figure 2.. Number of Explicit Emulations of a Target Trial Included in Review Published per Year
See this image and copyright information in PMC

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