Agreed on the general principle, but note that the incidence of SJS varies by drug. For example, lamotrigine causes SJS in 10-30% of people taking it, depending

Agreed on the general principle, but note that the incidence of SJS varies by drug. For example, lamotrigine causes SJS in 10-30% of people taking it, depending on how fast the dosage is increased. There they don't address it by trying to predict who will show SJS symptoms and who won't; they just put people in it slowly (which reduces incidence) and take people off the drug (or hold at a given dose until the body accepts the drug) if they show symptoms.