Skip to main content

01.12.2019 | Research article | Ausgabe 1/2019 Open Access

BMC Medicine 1/2019

Claims of causality in health news: a randomised trial

BMC Medicine > Ausgabe 1/2019
Rachel C. Adams, Aimée Challenger, Luke Bratton, Jacky Boivin, Lewis Bott, Georgina Powell, Andy Williams, Christopher D. Chambers, Petroc Sumner
Wichtige Hinweise

Electronic supplementary material

The online version of this article (https://​doi.​org/​10.​1186/​s12916-019-1324-7) contains supplementary material, which is available to authorized users.



Misleading news claims can be detrimental to public health. We aimed to improve the alignment between causal claims and evidence, without losing news interest (counter to assumptions that news is not interested in communicating caution).


We tested two interventions in press releases, which are the main sources for science and health news: (a) aligning the headlines and main causal claims with the underlying evidence (strong for experimental, cautious for correlational) and (b) inserting explicit statements/caveats about inferring causality. The ‘participants’ were press releases on health-related topics (N = 312; control = 89, claim alignment = 64, causality statement = 79, both = 80) from nine press offices (journals, universities, funders). Outcomes were news content (headlines, causal claims, caveats) in English-language international and national media (newspapers, websites, broadcast; N = 2257), news uptake (% press releases gaining news coverage) and feasibility (% press releases implementing cautious statements).


News headlines showed better alignment to evidence when press releases were aligned (intention-to-treat analysis (ITT) 56% vs 52%, OR = 1.2 to 1.9; as-treated analysis (AT) 60% vs 32%, OR = 1.3 to 4.4). News claims also followed press releases, significant only for AT (ITT 62% vs 60%, OR = 0.7 to 1.6; AT, 67% vs 39%, OR = 1.4 to 5.7). The same was true for causality statements/caveats (ITT 15% vs 10%, OR = 0.9 to 2.6; AT 20% vs 0%, OR 16 to 156). There was no evidence of lost news uptake for press releases with aligned headlines and claims (ITT 55% vs 55%, OR = 0.7 to 1.3, AT 58% vs 60%, OR = 0.7 to 1.7), or causality statements/caveats (ITT 53% vs 56%, OR = 0.8 to 1.0, AT 66% vs 52%, OR = 1.3 to 2.7). Feasibility was demonstrated by a spontaneous increase in cautious headlines, claims and caveats in press releases compared to the pre-trial period (OR = 1.01 to 2.6, 1.3 to 3.4, 1.1 to 26, respectively).


News claims—even headlines—can become better aligned with evidence. Cautious claims and explicit caveats about correlational findings may penetrate into news without harming news interest. Findings from AT analysis are correlational and may not imply cause, although here the linking mechanism between press releases and news is known. ITT analysis was insensitive due to spontaneous adoption of interventions across conditions.

Trial registration

ISRCTN10492618 (20 August 2015)
Über diesen Artikel

Weitere Artikel der Ausgabe 1/2019

BMC Medicine 1/2019 Zur Ausgabe

Neu im Fachgebiet Allgemeinmedizin

Mail Icon II Newsletter

Bestellen Sie unseren kostenlosen Newsletter Update Allgemeinmedizin und bleiben Sie gut informiert – ganz bequem per eMail.