- The percentage of missed appendicitis; this should not exceed 1%. In theory the LAPP score might lead to an increase in missed appendicitis. This might happen when a patient has an early or mild appendicitis without any of the 5 laparoscopic criteria for appendicitis. The investigators have defined 'missed appendicitis' as a confirmed appendicitis or appendicular infiltrate on a CT-scan or during a re-operation (within 3 months).