Thanks, both of you make good points. It probably would help if I called it "absolute" or "total risk" increase as that clarifies it. Of course stats is general

Thanks, both of you make good points. It probably would help if I called it "absolute" or "total risk" increase as that clarifies it. Of course stats is generally difficult for these vary reasons. > So ideally the information should be phrased as something like "this increases the chance of the thing from x% to y% over an average lifetime." I've personally never seen medicine info sheets give probabilities much less lifetime risks. > For context, if we simplify this to a binomial distribution for a 20 year old with 60 more years to live (i.e. we calculate for each year getting cancer=p), the lifespan chance of getting cancer increases from 26% to 45%. That would be more useful as well. > Also the probability of the event is actually around 1% here (around 1000 in 100000), so higher than the 0.5% you mentioned. It's really a rule of thumb for small values. In this case, I was interested in understanding the "4 extra people out of 100,000" as the article reports it (which is well below my 0.5% guideline) and not the baseline risk of illness per year. Ideally one compares both total and relative risks profiles. I'll be careful to add total risk vs relative risk to my descriptions in the future as that helps distinguish them.