Neglecting the null: the pitfalls of underreporting negative results in preclinical research

Abstract

Heightened competition for funding and increased pressure to publish in high-impact journals has led to a modern-day publication culture that favours positive results. The underreporting of negative, or null, results is a form of publication bias that occurs when researchers and/or reviewers fail to communicate findings due to unfavourable directionality or perceived unimportance. For nearly three decades, recognition of this bias in clinical research has led to revised policies and guidelines in an effort to improve reporting transparency and accuracy. Only recently has the existence of this reporting bias been fully appreciated as a formidable problem in preclinical research. Considering that preclinical research provides the foundation on which many clinical trials are conceived, finding solutions to increase the reporting accuracy of preclinical studies is of paramount importance. In this commentary, we will explore how the underreporting of negative results in preclinical research distorts scientific knowledge and subsequently misguides clinical research. We will conclude with several suggestions for reducing this bias with the intention of transitioning towards a truly transparent and objective publishing landscape.