Jam. You need to look at the actual difference between that reported in the active arm vs that in the placebo arm
If as an example 4% in the Vascepa arm but only 3% in the placebo arm ... complained of joint pain THEN you can say that 1% of all those prescribed Vascepa will likely experience actual joint pain because of the drug
As Pharmagirl noted ... as far as CV drugs go ... Vascepa probably has fewest side effects of them all JMO Kiwi