为什么科学新闻经常被夸大？

簡體傳統

众所周知，关于医学和健康的新闻经常存在错误，一般人或科学家可能觉得这是媒体记者的原因，但最近有一研究发现，导致这一问题的根源是科学家，而不是媒体记者。

首先要说明一下，理解医学进展有几个规矩，一是动物和细胞学研究不能等于人类的结果，因为生物体虽然是细胞组成的，但部分不等于整体，人和动物存在很多类似情况，但也存在巨大差别，所以细胞和动物研究结果只能作为人类的潜在可能结果，必须最终用人类实验才能作为最终的结论。当然在特殊情况下，用高等动物也能代替人类实验，例如关于埃博拉的研究，因为难以直接进行人类实验，用猴子的研究可以作为药物有效的依据。即使这样，也需要经过伦理学家和科学家进行讨论来临时决定。

二是存在相关性的因素不等于存在因果关系，关于因果关系不等于相关性的问题，有一个很有名的故事，生物学家把跳蚤的腿折断了，然后对跳蚤说：跳！跳蚤没有跳。于是生物学家得出结论，当跳蚤腿被折断的时候，跳蚤聋了。这就是将相关性简单推广到因果关系的形象说明。

这都应该是科学家和科技记者都非常明白的道理，但是到了具体文章中，出现这种错误的情况竟然非常普遍。

科学家总抱怨媒体在报道科技新闻经常存在错误或误导读者，但最新一项研究表明，至少在健康相关研究方面，导致这种问题的根源不是媒体，恰好是科学家自己。因为科技新闻几乎都是经过科学家同意的情况下公布的。英国国家卫生服务部营养师凯瑟琳柯林斯认为，学术领域应该为科技报道存在的错误负责。也有学者不认可这种说法，认为科技记者应该有自己的判断，应该为错误科技报道负责。

Abstract

Objective To identify the source (press releases or news) of distortions, exaggerations, or changes to the main conclusions drawn from research that could potentially influence a reader’s health related behaviour.

Design Retrospective quantitative content analysis.

Setting Journal articles, press releases, and related news, with accompanying simulations.

Sample Press releases (n=462) on biomedical and health related science issued by 20 leading UK universities in 2011, alongside their associated peer reviewed research papers and news stories (n=668).

Main outcome measures Advice to readers to change behaviour, causal statements drawn from correlational research, and inference to humans from animal research that went beyond those in the associated peer reviewed papers.

Results 40% (95% confidence interval 33% to 46%) of the press releases contained exaggerated advice, 33% (26% to 40%) contained exaggerated causal claims, and 36% (28% to 46%) contained exaggerated inference to humans from animal research. When press releases contained such exaggeration, 58% (95% confidence interval 48% to 68%), 81% (70% to 93%), and 86% (77% to 95%) of news stories, respectively, contained similar exaggeration, compared with exaggeration rates of 17% (10% to 24%), 18% (9% to 27%), and 10% (0% to 19%) in news when the press releases were not exaggerated. Odds ratios for each category of analysis were 6.5 (95% confidence interval 3.5 to 12), 20 (7.6 to 51), and 56 (15 to 211). At the same time, there was little evidence that exaggeration in press releases increased the uptake of news.

Conclusions Exaggeration in news is strongly associated with exaggeration in press releases. Improving the accuracy of academic press releases could represent a key opportunity for reducing misleading health related news.

http://www.bmj.com/content/349/bmj.g7015

这一发表在英国医学杂志(BMJ) 的研究论文，对2011年来自英国领先的20家学术机构462条新闻进行分析发现，在这些新闻中，大约40%的健康建议存在对原始引用文献的夸大。大约36%的新闻将细胞学和动物实验结果简单推广到人类。大约1/3的因果关系依据是相关性。在所有科技新闻中，这种现象更严重，58%存在夸大的健康建议，81%将相关关系作为因果关系，86%将动物和细胞研究随意推广到人类。