Naranjo ADR Probability Scale
Answer all ten questions. The total score gives the probability category. Points are shown beside each answer.
How the total is read
| Total score | Category |
|---|---|
| 9 or more | Definite |
| 5 to 8 | Probable |
| 1 to 4 | Possible |
| 0 or less | Doubtful |
Questions 4 and 6 need rechallenge or placebo data, which are rarely available. Without them the score usually stops at 7 or 8, so "Definite" is hard to reach for serious reactions (book, Appendix A.1.5).