{"id":34417,"date":"2026-02-20T09:45:46","date_gmt":"2026-02-20T09:45:46","guid":{"rendered":"https:\/\/clearingtheair.eu\/?p=34417"},"modified":"2026-02-20T09:45:53","modified_gmt":"2026-02-20T09:45:53","slug":"flawed-switching-label-may-skew-vape-health-findings-new-analysis-shows","status":"publish","type":"post","link":"https:\/\/clearingtheair.eu\/en\/post\/flawed-switching-label-may-skew-vape-health-findings-new-analysis-shows\/","title":{"rendered":"Flawed \u201cswitching\u201d label may skew vape health findings, new analysis shows"},"content":{"rendered":"\n<ul class=\"wp-block-list\">\n<li><strong>Two recent studies grouped some ongoing cigarette smokers under the label \u201cEC switchers,\u201d potentially distorting comparisons.<\/strong><\/li>\n\n\n\n<li><strong>In both papers, people classified as using vapes had significantly lower risks of certain major health outcomes than those who continued smoking.<\/strong><\/li>\n\n\n\n<li><strong>When complete switchers were analysed separately, effect sizes were similar to those who quit nicotine entirely, but small sample sizes limited statistical significance.<\/strong><\/li>\n\n\n\n<li><strong>One study recommended against switching despite reporting similar risk reductions to complete abstinence.<\/strong><\/li>\n<\/ul>\n\n\n\n<p><strong>A new critique has raised concerns about how two recent health studies defined \u201cswitching\u201d from cigarettes to vapes &#8211; and whether that definition could influence how the findings are understood.<\/strong><\/p>\n\n\n\n<p>In <a href=\"https:\/\/arielleselyaphd.substack.com\/p\/new-research-flaw-unlocked\" rel=\"nofollow noopener\" target=\"_blank\">a post<\/a> titled <strong>\u201cNew Research Flaw Unlocked?\u201d,<\/strong> behavioural scientist Arielle Selya, PhD, reviewed two Korean studies that analysed national health insurance data. Both followed patients who smoked cigarettes and had serious health conditions at baseline.\u00a0<\/p>\n\n\n\n<p>Researchers then compared health outcomes roughly five years later, based on whether participants continued smoking, used vapes, or quit nicotine entirely about one year after baseline.<\/p>\n\n\n\n<p>The <a href=\"https:\/\/link.springer.com\/article\/10.1186\/s12931-026-03545-1\" rel=\"nofollow noopener\" target=\"_blank\">first study<\/a> examined patients with chronic obstructive pulmonary disease (COPD) and tracked outcomes including lung cancer, COPD exacerbations, major adverse cardiac and cerebrovascular events (MACCE), and all-cause mortality. The <a href=\"https:\/\/doi.org\/10.1016\/j.ypmed.2026.108530\" rel=\"nofollow noopener\" target=\"_blank\">second<\/a> focused on patients with hepatitis B and tracked the development of hepatocellular carcinoma, a form of liver cancer.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>The definition of \u201cswitching\u201d<\/strong><\/h3>\n\n\n\n<p>According to Selya, the central issue lies in how the studies defined \u201cEC switchers.\u201d She wrote: \u201cThe critical flaw is that the \u2018EC switchers\u2019 group still includes cigarette smoking.\u201d<\/p>\n\n\n\n<p>She added: \u201c\u2018Switched\u2019 usually means they switched completely away from cigarettes. Here, it doesn\u2019t mean \u2018fully switched,\u2019 or even \u2018mostly switched\u2019; it just means they used e-cigarettes, and they don\u2019t distinguish from people who switched completely versus dual-used.\u201d<\/p>\n\n\n\n<p>In other words, some participants categorised as having switched were still smoking cigarettes as well as using vapes. That means <strong>the \u201cswitcher\u201d group may have included both complete switchers and dual users.<\/strong><\/p>\n\n\n\n<p>Dual use can carry ongoing risks associated with smoking. Grouping these participants together with complete switchers could make it harder to see differences between people who stopped smoking entirely and those who continued to smoke.<\/p>\n\n\n\n<p>Selya also suggested it was unclear whether the starting sample included only exclusive smokers, writing that \u201cIt\u2019s hard to tell because the sample inclusion criteria aren\u2019t described thoroughly.\u201d If some participants were already dual users at baseline, that could further complicate comparisons.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>What the studies found<\/strong><\/h3>\n\n\n\n<p>Despite the grouping issue identified in the critique, both studies reported statistically significant reductions in certain major health risks among participants classified as using vapes compared with those who continued smoking.<\/p>\n\n\n\n<p>In the COPD study, participants using vapes after one year had significantly lower odds of major adverse cardiac and cerebrovascular events at five years (adjusted hazard ratio, AHR = 0.80). Those who quit nicotine entirely showed a similar reduction (AHR = 0.85).<\/p>\n\n\n\n<p>Other outcomes in the COPD study, including COPD exacerbations and all-cause mortality, did not show statistically significant differences.<\/p>\n\n\n\n<p>In the hepatitis B study, participants using vapes after one year had significantly lower odds of developing liver cancer (AHR = 0.78), which was the same magnitude of risk reduction observed among those who quit nicotine completely (AHR = 0.78).<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Separate analyses of complete switchers<\/strong><\/h3>\n\n\n\n<p>Selya noted that additional analyses in the COPD study separated complete switchers from dual users. These analyses did not reach statistical significance, which she attributed to small sample sizes and wide confidence intervals.<\/p>\n\n\n\n<p>However, she wrote that \u201cwith the exception of lung cancer, all other outcomes have a similarly-sized reduction for complete switchers and complete nicotine abstainers.\u201d<\/p>\n\n\n\n<p>The critique also questioned how non-significant results were described. In the COPD paper, she wrote that non-significant findings were characterised as \u201cnot providing comparable.. benefits\u201d compared with quitting.<\/p>\n\n\n\n<p>In the hepatitis B paper, the authors concluded: \u201cComplete tobacco cessation should remain the primary strategy given superior behavioral sustainability, with no significant difference in HCC risk reduction versus switching.\u201d<\/p>\n\n\n\n<p>Selya summarised this as: \u201cSwitching to ECs was associated with the same risk reduction in liver cancer as complete nicotine abstinence, but we recommend against switching to ECs because it\u2019s not as stable\/sustainable.\u201d<\/p>\n\n\n\n<p>The hepatitis B paper also reported that only 12% of those classified as \u201cEC switchers\u201d eventually quit smoking, compared with 61% of those who initially quit.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Peer review and presentation<\/strong><\/h3>\n\n\n\n<p>The critique noted that analyses of complete switchers in the COPD paper appeared in red font in a pre-formatted version of the manuscript, suggesting they may have been added during peer review.<\/p>\n\n\n\n<p>Selya described this as \u201ca success of peer review because the paper would have been almost completely uninformative without it.\u201d<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>She concluded by warning that terminology matters in research and reporting. She wrote that sometimes \u201c \u2018EC switchers\u2019 means \u2018EC switchers and dual users,\u2019 in future research and in any media coverage these studies get.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p>The analysis highlights how definitions and grouping decisions in epidemiological studies can shape the way findings are presented &#8211; and how careful scrutiny of study methods is essential when interpreting research on smoking, vaping and long-term health outcomes.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A new critique has raised concerns about how two recent health studies defined \u201cswitching\u201d from cigarettes to vapes &#8211; and whether that definition could influence how the findings are understood. In a post titled \u201cNew Research Flaw Unlocked?\u201d, behavioural scientist Arielle Selya,&hellip;<\/p>\n","protected":false},"author":990002,"featured_media":34418,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[257,259],"tags":[186],"slider":[],"class_list":["post-34417","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","category-science","tag-nicotine"],"_links":{"self":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts\/34417","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/users\/990002"}],"replies":[{"embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/comments?post=34417"}],"version-history":[{"count":1,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts\/34417\/revisions"}],"predecessor-version":[{"id":34425,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/posts\/34417\/revisions\/34425"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/media\/34418"}],"wp:attachment":[{"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/media?parent=34417"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/categories?post=34417"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/tags?post=34417"},{"taxonomy":"slider","embeddable":true,"href":"https:\/\/clearingtheair.eu\/en\/wp-json\/wp\/v2\/slider?post=34417"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}