Cost-effectiveness of prophylactic appendectomy: a Markov model

Appendectomy is the most common emergency surgery performed in the USA. Removal of a non-inflamed appendix during unrelated abdominal surgery (prophylactic or incidental appendectomy) can prevent the downstream risks and costs of appendicitis. It is unknown whether such a strategy could be cost saving for the health system.

We considered hypothetical patient cohorts of varying ages from 18 to 80, undergoing elective laparoscopic abdominal and pelvic procedures. A Markov decision model using cost per life-year as the main outcome measure was constructed to simulate the trade-off between cost and risk of prophylactic appendectomy and the ongoing risk of developing appendicitis, with downstream costs and risks. Rates, probabilities, and costs of disease, treatment, and outcomes by patient age and gender were extracted from the literature. Sensitivity analyses were conducted using complications and costs of prophylactic appendectomy.

With our base-case assumptions, including added cost of prophylactic appendectomy of $660, we find that prophylactic removal of the appendix is cost saving for males aged 18-27 and females aged 18-28 undergoing elective surgery. The margin of cost savings depends on remaining life-years and increases exponentially with age: a 20-year-old female undergoing elective surgery could save $130 over a lifetime by undergoing prophylactic appendectomy, while a 40-year-old female would lose $130 over a lifetime. When the risk of the prophylactic appendectomy exceeds the risk of laparoscopic appendectomy for appendicitis or the cost exceeds $1080, it becomes more cost saving to forego the prophylactic procedure.

Prophylactic appendectomy can be cost saving for patients younger than age thirty undergoing elective laparoscopic abdominal and pelvic procedures.