A survey of experts to identify methods to detect problematic studies: stage 1 of the INveStigating ProblEmatic Clinical Trials in Systematic Reviews project

Background and objective: Randomized controlled trials (RCTs) inform health-care decisions. Unfortunately, some published RCTs contain false data, and some appear to have been entirely fabricated. Systematic reviews are performed to identify and synthesize all RCTs which have been conducted on a given topic. This means that any of these 'problematic studies' are likely to be included, but there are no agreed methods for identifying them. The INveStigating ProblEmatic Clinical Trials in Systematic Reviews (INSPECT-SR) project is developing a tool to identify problematic RCTs in systematic reviews of health care-related interventions. The tool will guide the user through a series of 'checks' to determine a study's authenticity. The first objective in the development process is to assemble a comprehensive list of checks to consider for inclusion.

Methods: We assembled an initial list of checks for assessing the authenticity of research studies, with no restriction to RCTs, and categorized these into five domains: Inspecting results in the paper; Inspecting the research team; Inspecting conduct, governance, and transparency; Inspecting text and publication details; Inspecting the individual participant data. We implemented this list as an online survey, and invited people with expertise and experience of assessing potentially problematic studies to participate through professional networks and online forums. Participants were invited to provide feedback on the checks on the list, and were asked to describe any additional checks they knew of, which were not featured in the list.

Results: Extensive feedback on an initial list of 102 checks was provided by 71 participants based in 16 countries across five continents. Fourteen new checks were proposed across the five domains, and suggestions were made to reword checks on the initial list. An updated list of checks was constructed, comprising 116 checks. Many participants expressed a lack of familiarity with statistical checks, and emphasized the importance of feasibility of the tool.

Conclusion: A comprehensive list of trustworthiness checks has been produced. The checks will be evaluated to determine which should be included in the INSPECT-SR tool.

Plain language summary: Systematic reviews draw upon evidence from randomized controlled trials (RCTs) to find out whether treatments are safe and effective. The conclusions from systematic reviews are often very influential, and inform both health-care policy and individual treatment decisions. However, it is now clear that the results of many published RCTs are not genuine. In some cases, the entire study may have been fabricated. It is not usual for the veracity of RCTs to be questioned during the process of compiling a systematic review. As a consequence, these "problematic studies" go unnoticed, and are allowed to contribute to the conclusions of influential systematic reviews, thereby influencing patient care. This prompts the question of how these problematic studies could be identified. In this study, we created an extensive list of checks that could be performed to try to identify these studies. We started by assembling a list of checks identified in previous research, and conducting a survey of experts to ask whether they were aware of any additional methods, and to give feedback on the list. As a result, a list of 116 potential "trustworthiness checks" was created. In subsequent research, we will evaluate these checks to see which should be included in a tool, INveStigating ProblEmatic Clinical Trials in Systematic Reviews, which can be used to detect problematic studies.