Hidden flaws in e-cigarette industry-funded studies.

Electronic cigarette (e-cigarette) use has increased since e-cigarettes were introduced to the market nearly 20 years ago. Researchers continue to conduct studies to understand the health risks and benefits of e-cigarettes to inform health education and promotion efforts as well as public policy. Studies funded by the tobacco industry examining the potential risks and benefits of e-cigarettes have also been conducted and are sometimes published in the scientific literature. Frequently, tobacco and e-cigarette industry-funded researchers report findings that contradict research funded by other sources. While many industry-funded studies may appear methodologically sound at first glance, in some cases, industry-funded studies include methodological flaws that result in misleading conclusions. The tobacco industry's use of biased research to influence tobacco-related policy decisions in the past is well-documented. This commentary provides specific examples of recent e-cigarette research funded by the tobacco/e-cigarette industry in which methodological flaws result in misleading conclusions that support industry goals. Given the long history of biased research conducted by the tobacco industry, there is a need to assess whether research funded by the e-cigarette industry similarly contains methodological flaws. We emphasise the need for tobacco and e-cigarette-funded research to be scrutinised by non-industry-funded subject matter experts and call for journals to not consider manuscripts that have received support from the tobacco or e-cigarette industry.