A review of pragmatic trials found a high degree of diversity in design and scope, deficiencies in reporting and trial registry data, and poor indexing

Stuart G. Nicholls, Kelly Carroll, Spencer Phillips Hey, Merrick Zwarenstein, Jennifer Zhe Zhang, Hayden P. Nix, Jamie C. Brehaut, Joanne E. McKenzie, Steve McDonald, Charles Weijer, Dean A. Fergusson, Monica Taljaard

Research output: Contribution to journalArticleResearchpeer-review

18 Citations (Scopus)


Objective: We established a large database of trials to serve as a resource for future methodological and ethical analyses. Here, we use meta-data to describe the broad landscape of pragmatic trials including research areas, identification as pragmatic, quality of trial registry data and enrolment. Study Design and Setting: Trials were identified by a validated search filter and included if a primary report of a health-related randomized trial published January 2014-April 2019. Data were collated from MEDLINE, Web of Science, ClinicalTrials.gov, and full text. Results: 4337 eligible trials were identified from 13,065 records, of which 1988 were registered in ClinicalTrials.gov. Research areas were diverse, with the most common being general and internal medicine; public, environmental and occupational health; and health care sciences and services. The term “pragmatic” was seldom used in titles or abstracts. Several domains in ClinicalTrials.gov had questionable data quality. We estimated that one-fifth of trials under-accrued by at least 15%. Conclusion: There is a need to improve reporting of pragmatic trials and quality of trial registry data. Under accrual remains a challenge in pragmatic RCTs despite calls for more streamlined recruitment approaches. The diversity of pragmatic trials should be reflected in future ethical analyses.

Original languageEnglish
Pages (from-to)45-57
Number of pages13
JournalJournal of Clinical Epidemiology
Publication statusPublished - Sept 2021


  • Data quality
  • Database searching
  • Intervention
  • Pragmatic trials
  • Registration
  • Reporting
  • Trial design

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