Prospective Validation of the APPEND Clinical Prediction Rule for Appendicitis: A Cohort Study

Area of Science:

• General Surgery
• Clinical Decision Making

Background:

• Right iliac fossa (RIF) pain is a common surgical presentation.
• Acute appendicitis is a frequent diagnosis, but clinical diagnosis remains challenging.
• Clinical prediction rules (CPRs) aim to enhance diagnostic accuracy and decrease negative appendicectomy rates.

Purpose of the Study:

• To prospectively assess the performance of the APPEND score CPR.
• To evaluate the APPEND score within a dedicated RIF pain management pathway.

Main Methods:

• A prospective cohort study was conducted from January to July 2016.
• This pathway was compared to a retrospective cohort used for APPEND score development.
• The primary outcome measured was the rate of negative appendicectomy.

Main Results:

• The prospective cohort showed a negative appendicectomy rate of 9.2%, significantly lower than the retrospective cohort's 19.8%.
• The odds of negative appendicectomy were 2.33 times higher in the retrospective cohort.
• The APPEND score demonstrated high specificity (≥5, 87%) and sensitivity (≥1, 100%) for diagnosing appendicitis.

Conclusions:

• Implementing the APPEND CPR within an RIF pain pathway led to a >50% reduction in negative appendicectomy rates.
• The APPEND score is effective in improving diagnostic accuracy for appendicitis.