Operative Versus Nonoperative Management of Appendicitis: A Long-Term Cost Effectiveness Analysis

Abstract

<b>Background.</b> Recent clinical trials suggest that nonoperative management (NOM) of patients with acute, uncomplicated appendicitis is an acceptable alternative to surgery. However, limited data exist comparing the long-term cost-effectiveness of nonoperative treatment strategies. <b>Design.</b> We constructed a Markov model comparing the cost-effectiveness of three treatment strategies for uncomplicated appendicitis: 1) laparoscopic appendectomy, 2) inpatient NOM, and 3) outpatient NOM. The model assessed lifetime costs and outcomes from a third-party payer perspective. The preferred strategy was the one yielding the greatest utility without exceeding a $50,000 willingness-to-pay threshold. <b>Results.</b> Outpatient NOM cost $233,700 over a lifetime; laparoscopic appendectomy cost $2500 more while inpatient NOM cost $7300 more. Outpatient NOM generated 24.9270 quality-adjusted life-years (QALYs), while laparoscopic appendectomy and inpatient NOM yielded 0.0709 and 0.0005 additional QALYs, respectively. Laparoscopic appendectomy was cost-effective compared with outpatient NOM (incremental cost-effectiveness ratio $32,300 per QALY gained); inpatient NOM was dominated by laparoscopic appendectomy. In one-way sensitivity analyses, the preferred strategy changed when varying perioperative mortality, probability of appendiceal malignancy or recurrent appendicitis after NOM, probability of a complicated recurrence, and appendectomy cost. A two-way sensitivity analysis showed that the rates of NOM failure and appendicitis recurrence described in randomized trials exceeded the values required for NOM to be preferred. <b>Limitations.</b> There are limited NOM data to generate long-term model probabilities. Health state utilities were often drawn from single studies and may significantly influence model outcomes. <b>Conclusion.</b> Laparoscopic appendectomy is a cost-effective treatment for acute uncomplicated appendicitis over a lifetime time horizon. Inpatient NOM was never the preferred strategy in the scenarios considered here. These results emphasize the importance of considering long-term costs and outcomes when evaluating NOM.