Evidence from a well-designed randomized controlled trial (RCT) is generally considered to be the gold standard that can inform clinical practice and guide decision-making. However, several deficiencies in the reporting of RCTs have frequently been identified, including incomplete, selective, and biased or inconsistent reporting. Such suboptimal reporting may lead to irreproducible results, substantial waste of resources, impaired study validity, erosion of public trust in science, and a high risk of research misconduct. In this article, we present an overview of the reporting of RCTs in the biomedical literature with a focus on the three most common reporting problems: (i) lack of adherence to reporting guidelines, (ii) inconsistencies between trial protocols or registrations and full reports, and (iii) inconsistencies between abstracts and their corresponding full reports. Unsatisfactory levels of adherence to guidelines and frequent inconsistencies between protocols or registrations and full reports, and between abstracts and full reports, were consistently found in various biomedical research fields. A variety of factors were found to be associated with these reporting challenges. Improved reporting can build public trust and credibility of science, save resources, and enhance the ethical integrity of research. Therefore, joint efforts from the various sectors of the biomedical community (researchers, journal editors and reviewers, educators, healthcare providers, and other research consumers) are needed to reduce and reverse the current suboptimal state of RCT reporting in the literature.
Keywords: guideline adherence; inconsistent reporting; randomized controlled trial; reporting quality; transparency.