https://www.gov.uk/government/news/phe-publishes-independent...
I'm just going to say that this looks like the least rigorous assessment that I've ever seen. As far as I can tell, they went to a conference and over a 2 day period collectively came up with a list of "evaluation criteria" which is not at all limited to health. It includes (among other things) crime, environmental damage, family adversities, economic cost, community,etc, etc).
Then they scored each product against each criteria on a 100 point scale. This is not an evidenced based approach. It was a bunch of people sitting in a room arguing with each other how they think it should be scored.
Then they weighted the results. Finally they gave each a final score of "harm" base on a 100 point scale. Cigarettes ranked at 100. Pipe smoking ranked at 21 (nearly 5x "safer" than cigarettes!) ENDS ranked about 4 (based on what I can guess from the graph). There's your "at least 95% 'safer'" tag line.
Oh and the committee included a consultant working with companies on tobacco dependence, another consultant working with smoking cessation products, and another consultant working for an e-sig distributor. Several of the committee received grants from the nicotine industry.
[1] - https://www.karger.com/article/FullText/360220 [2] - https://www.gov.uk/government/uploads/system/uploads/attachm...
Here's an example of a gaping gap in research on e-cigs: "To our knowledge, there are no relevant study in humans on carcinogenic effects from pure nicotine including products, such as NRT and e-cigarettes." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4553893/
It's really hard to summarize a body of research if there's barely any research been done in an area.