Research on vaping is sparse, so each new paper is held in high regard. This is true of the paper published by the peer-reviewed journal Gastroenterology Research. The paper, Association of Smoking and E-Cigarettes in Chronic Liver Disease: An NHANES Study 1R. C. Chakinala, S. Dawoodi, S. P. Fabara, M. Asad, A. Khayyat, S. Chandramohan, A. Aslam, N. Unachukwu, B. Nasyrlaeva, R. Jaiswal, S. B. Chowdary, P. Malik, and R. Rabbani, Association of Smoking and E-Cigarette in Chronic Liver Disease: An NHANES Study, Gastroenterology Res, vol. 15, no. 3, pp. 113–119, Jun. 2022., was first published in June 2022. It concluded that e-cigarette users have ‘higher odds of having liver disease compared to non-smokers.’
Soon after the paper was published, the editor received a letter that questioned the validity of the paper. The letter to the editor has not been made public, but we know that the journal was concerned about the ‘methodology, source data processing […] and reliability of conclusions’ in the paper.
Researchers who conducted the study based their findings on the National Health and Nutrition Examination Survey (NHANES), a survey that is designed to assess the health of children and adults in the United States.
Ray Niaura, an epidemiology professor at New York University’s School of Public Health, highlighted the insubstantial focus on vaping in the survey. The only survey question on vaping was a broad one 2S. Nautiyal, Experts want Gastroenterology Research to publish letter that led to study paper retraction, PharmaBiz, Mumbai, Jul. 29, 2023., Niaura says. Researchers compared the answers to ‘Have you ever used an e-cigarette?’ to answers about combustible cigarettes.
“A lack of robust methodology seems to be the leading cause of flawed research.”
Researchers asked participants whether they had smoked ‘at least 100 cigarettes’ in their lifetime. As Niaura points out, this is a ‘weak variable’, but it is especially alarming that researchers tried to base their conclusions on it. The researchers also failed to consider the timing of the development of lung cancer, another vital metric for any sound conclusions.
The journal officially retracted the paper on June 11th, 2023, an entire year after its publication. This is not the first time that misinformation about vaping has been published.
Riccardo Polosa, Founder of the CoEHAR, and Konstantinos Farsalinos, a research fellow at the Onassis Cardiac Surgery Center in Athens, recently published A tale of flawed e-cigarette research undetected by defective peer review process 3R. Polosa and K. Farsalinos, A tale of flawed e-cigarette research undetected by defective peer review process, Intern Emerg Med, vol. 18, no. 4, pp. 973–975, Jun. 2023. in the journal of the Italian Society of Internal Medicine. The researchers emphasize that many studies ‘fail to include the information on the age of initiation of e-cigarette and combustible cigarette use’ and that this failure stops them from forming any evidence-based opinions.
Another group of researchers who operate under CoEHAR pointed out similar flaws in 24 of the most well-known vaping studies. The resulting review, titled Analysis of common methodological flaws in the highest cites e-cigarette epidemiology research 4C. Hajat, E. Stein, A. Selya, R. Polosa, and CoEHAR study group, Analysis of common methodological flaws in the highest cited e-cigarette epidemiology research, Intern Emerg Med, vol. 17, no. 3, pp. 887–909, Apr. 2022., found that many studies ‘lacked a clear hypothesis statement’ and that ‘the methods were not tailored to address the question of interest.’ Yet more problems arose, with the most eye-catching being the ‘failure to control for confounding factors.’
A lack of robust methodology seems to be the leading cause of flawed research, but why? The answer may lie in the relatively short time that vape devices have been around, compounded by frenzied anti-vape arguments and campaigns. The rush to find evidence one way or the other might have led researchers to rely on insufficient or unsuitable data sources, as is evident in the NHANES Study.
