Key Concepts for Informed Health Choices:
Introduction to the Informed Health Choices Essays

Cite as: Oxman AD, Chalmers I, Dahlgren A (2022). Key Concepts for Informed Health Choices: 1. Introduction to the Informed Health Choices Essays. James Lind Library (

© Andy Oxman, Centre for Epidemic Interventions Research, Norwegian Institute of Public Health, Norway. Email:

The Explanatory Essays in The James Lind Library were written to promote wider understanding of why fair tests of treatments are needed, and what they have come to consist of [Chalmers 2008, Clarke 2019] . The Informed Health Choices Essays complement the Explanatory Essays by focusing on the use of information from fair tests of treatments to inform decisions.

The world is awash in health information, including an abundance of false or inaccurate information – misinformation. Believing and acting on misinformation can result in wasted resources and harm. Not believing and acting on reliable information can also result in waste, harm, and unnecessary suffering.

Assessing the reliability or trustworthiness of information about treatments requires understanding and application of key concepts – general principles that are “applicable in a great variety of different instances in spite of their difference,” and can “serve as points of reference by which to get our bearings when we are plunged into the strange and unknown” [Dewey 1933] .

The Informed Health Choices Essays present three sets of concepts that can help people to assess claims about the effects of treatments and to make informed health choices:

  1. concepts that can help you recognise when a claim about the effects of treatments has an untrustworthy basis,
  2. concepts that can help you recognise when evidence from comparisons (tests) of treatments is trustworthy and when it is not, and
  3. concepts that can help you to make well-informed choices about treatments.

The concepts within each set are grouped under high-level concepts (Table 1). These essays provide an overview of the Key Concepts in each of those groups, and then address why and how it is important to teach these concepts from primary school onwards. They can help anyone, not just researchers, to think critically about whether to believe a treatment claim and what to do.

Essay number High-level concepts
0) Introduction to the Informed Health Choices Essays
1) Avoid being misled by claims that have an untrustworthy basis.
1.1 Assumptions that treatments are safe or effective can be misleading.
1.2 Seemingly logical assumptions about research can be misleading.
1.3 Seemingly logical assumptions about treatments can be misleading.
1.4 Trust based on the source of a claim alone can be misleading.
2) Consider whether evidence from comparisons is trustworthy.
2.1 Comparisons of treatments should be fair.
2.2 Reviews of the effects of treatments should be fair.
2.3 Descriptions of effects should clearly reflect the size of the effects.
2.4 Descriptions of effects should reflect the risk of being misled by the play of chance.
3) Make well-informed choices.
3.1 Evidence should be relevant.
3.2 Expected advantages should outweigh expected disadvantages.

In these essays, we use the term “treatment” to include any intervention (action) intended to improve health, including preventive, therapeutic and rehabilitative interventions, and public health or health system interventions. Although the focus of these essays is on treatment claims, people in other disciplines have found most of the same concepts to be relevant for assessing claims about the effect of actions taken to improve, for example, agriculture, education, or the environment [Aronson 2019].

We use the term “fair comparison” rather than “fair test” to avoid confusion with diagnostic tests, and to emphasize that fair tests of treatments always involve a comparison with some other treatment (or withholding a treatment).

The basis for the concepts that are explained in these essays is described elsewhere [Oxman 2022b], as is their development and revisions between 2013 and 2022 [Austvoll-Dahlgren 2015, Chalmers 2018, Oxman 2022a, Oxman 2019].


Aronson JK, Barends E, Boruch R, Brennan M, Chalmers I, Chislett J, Cunliffe-Jones P, Dahlgren A, Gaarder M, Haines A, Heneghan C, Matthews R, Maynard B, Oxman AD, Oxman M, Pullin A, Randall N, Roddam H, Schoonees A, Sharples J, Stewart R, Stott J, Tallis R, Nerys Thomas N, Val L (2019). Key concepts for making informed choices. Nature 572:303-6.

Austvoll-Dahlgren A, Oxman AD, Chalmers I, Nsangi A, Glenton C, Lewin S Morelli A, Rosenbaum S, Semakula D, Sewankambo N (2015). Key concepts that people need to understand to assess claims about treatment effects. J Evid Based Med 8:112-25.

Chalmers I, Milne I, Tröhler U, Vandenbroucke J, Morabia A, Tait G, Dukan E (2008). The James Lind Library: explaining and illustrating the evolution of fair tests of medical treatments. Journal of the Royal College of Physicians of Edinburgh 38:259-64.

Chalmers I, Atkinson P, Badenoch D, Glasziou P, Austvoll-Dahlgren A, Oxman A, Clarke M (2019). The James Lind Initiative: books, websites and databases to promote critical thinking about treatment claims, 2003 to 2018. Research Involvement and Engagement 5:6.

Chalmers I, Oxman AD, Austvoll-Dahlgren A, Ryan-Vig S, Pannell S, Sewankambo N, Semakula D, Nsangi A, Albarqouni L, Glasziou P, Mahtani K, Nunan D, Heneghan C, Badenoch D (2018). Key Concepts for Informed Health Choices: a framework for helping people learn how to assess treatment claims and make informed choices. BMJ Evid Based Med 23:29-33.

Dewey J (1933). The educational significance of concepts.  How We Think: A Restatement of the Relation of Reflective Thinking to the Educative Process. 2nd ed. Boston: DC Heath and Company p. 153-4.

Oxman A, Chalmers I, Dahlgren A (2022a). Key Concepts for Informed Health Choices: Where’s the evidence? F1000Res.

Oxman AD, Chalmers I, Austvoll-Dahlgren A, Informed Health Choices Group (2019). Key Concepts for assessing claims about treatment effects and making well-informed treatment choices. F1000Res 7:1784.

Oxman AD, Chalmers I, Dahlgren A, Informed Health Choices Group (2022b). Key Concepts for Informed Health Choices: a framework for enabling people to think critically about health claims (Version 2022). IHC Working Paper.