LAUSR

BACKGROUND Controversy exists about the preferred initial treatment of appendicitis. We sought to compare the two treatments for initial management of simple appendicitis. METHODS In this post hoc analysis of the Multicenter Study for the Treatment of Appendicitis in America: Acute, Perforated, and Gangrenous database, subjects were divided into appendectomy or nonoperative management (NOM; antibiotics only or percutaneous drainage) cohorts. A novel topic-specific hierarchical ordinal scale was created with eight mutually exclusive categories: mortality, reoperation, other secondary interventions, readmission, emergency department visit, wound complication, surgical site infection, and no complication. Pairwise comparisons of American Association for the Surgery of Trauma Imaging Severity Grade 1 (simple appendicitis) patients were compared using win-lose-tie scoring and the sums of appendectomy/NOM groups were compared. RESULTS A total 3,591 subjects were included: 3,262 appendectomy and 329 NOM, with significant differences in baseline characteristics between groups. Across 28 sites, the rate of NOM ranged from 0% to 48%, and the loss to follow-up rate was significantly higher for NOM compared with appendectomy (16.5% vs. 8.7%, p = 0.024). In the simple appendicitis hierarchical ordinal scale analysis, 2,319 subjects resulted in 8,714,304 pairwise comparisons; 75% of comparisons resulted in ties. The median (interquartile range) sums for the two groups are as follows: surgical, 400 (400–400), and NOM, 400 (−2,427 to 400) (p < 0.001). A larger proportion of appendectomy subjects (88.1%) had an outcome that was equivalent (or better) than at least half of the subjects compared with NOM subjects (NOM, 70.5%; OR [95% confidence interval], 0.3 [0.2–0.4]). CONCLUSION In contemporary American practice, appendectomy (compared with NOM) for simple appendicitis is associated with lower odds of developing clinically important unfavorable outcomes in the first year after illness. LEVEL OF EVIDENCE Therapeutic/Care Management; Level III.