Systematic Reviews including Non-Randomized Studies

Annette M. O’Connor, BVSc, MVSc, DVSc, Member of the Australian College of Veterinary Scientists (Epidemiology), Fellow of the Australian College of Veterinary Scientists (Epidemiology)

Professor, Veterinary Diagnostic and Production Animal Medicine, Iowa State University College of Veterinary Medicine

Proceedings Paper (PDF) Slides (PDF) Screencast (video)
Download proceedings paper (PDF) Download slide deck (PDF) Stream presentation video

Please note: Some proceedings papers or presentation slide decks were not made available by the speaker. Also, selected screencast recordings from the webinar may be viewed only by active EBVMA members after logging into their member portal.


While the randomised-controlled trial is considered the gold standard to ensure that study subjects under evaluation are only being compared based on the impact of the study intervention, the paucity of RCTs in veterinary medicine make this especially challenging in conducting systematic reviews of interventions. Also not all review questions relate to interventions. This presentation will talk about the benefits and risks , trends and criticisms, and unique design features in the use of non-randomized clinial study designs.

In this section we will discuss the important considerations that must be made when including non-randomized studies into an evidence base. The session will discuss how the role of non-randomized studies might differ based on the different types of review questions – interventions, causation, prevalence and diagnostic tests. The contribution of non-randomized studies to the evidence base and the potential sources of bias must be careful considered at the protocol development stage. At this protocol development stage of the review decisions need to be made about if such studies will be eligible for the review. If it is decided to included non randomizes studies as part of the evidence base, the protocol should outline what risk domains will be considered when assessing the risk of bias.


systematic reviews, non-randomized studies, evidence-based medicine

All content from "Best Evidence, Better Care", the 7th EBVMA Symposium held Friday, 11 November 2015 is © 2015 by the EBVMA (publication) and the author (content) under a Creative Commons Attribution, Non-Commercial, Share-alike, 4.0, International License. Some content may be restricted to active EBVMA members. See our membership page to join or renew or send us an email to If you're interested in speaking or participating in our AAVSB/RACE accredited continuing education programs, contact us at

Series Navigation<< Keynote: Missing TrialsThe Electronic Health Record as an EBM Platform: Context-Aware Knowledge Retrieval (Infobuttons) >>