Patients in the subgroup of extra high probability (score ≥18) could be scheduled to surgery without any further investigations or follow-up. In high probability group (score ≥16), diagnostic accuracy improved when clinical assessment was taken into account. Accuracy was best when score results and the actual diagnostics were combined. When both the score and the surgeon suggested surgery, half of all appendicitis patients were recognised with rate of negative appendectomies as low as 4.3%.